MICRO102A - Veterinary Bacteriology and Mycology Lec (2nd Semester 2025-2026) PDF

MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA to blood clots and traumatized tissues LESSON 1: STAPHY...

MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA to blood clots and traumatized tissues LESSON 1: STAPHYLOCOCCUS c.​ Collagen-binding factor MORPHOLOGICAL CHARACTERISTICS -​ Infections associated with in-dwelling medical devices such as -​ Perfectly spherical Gram (+) cocci IV catheters, prosthetic joints, approx. 0.5 to 1u in diameter replacements heart valves) -​ Grow in clusters like a bunch of ​ Biomaterial implanted in grapes (Greek word “staphylo”) human body becomes coated with complex Two pigmented colony types mixtures of host proteins ​ S. aureus and platelets (fibrinogen is -​ golden yellow dominant component) -> adherence of S. aureus ​ S. albus / S.epidermidis ​ If material is in the body for -​ white long periods, fibrinogen is degraded and no longer promote bacterial PATHOGENESIS attachment ​ Fibronectin becomes VIRULENCE FACTORS predominant ligand promoting attachment 1.​ SURFACE PROTEINS 2.​ FACTORS THAT INHIBIT PHAGOCYTOSIS - CAPSULE, -​ promote colonization of host tissues IMMUNOGLOBULIN-BINDING such as those that promote PROTEIN A attachment to host a.​ Capsular polysaccharide a.​ Surface proteins promote -​ surface polysaccharide of serotype attachment to host proteins such as 5 or 8 laminin and fibronectin that form -​ Called microcapsule because it can part of the extracellular matrix be visualized only by electron microscopy after antibody labelling -​ Fibronectin present on epithelial -​ Polysaccharide rapidly lost upon and endothelial surfaces as well as laboratory subculture component of blood clots -​ Function not clear but may impede phagocytosis b.​ Fibrinogen/fibrin binding (clumping factor) which promotes attachment MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA b.​ Protein A surface protein of S. -​ Classical test is the lysis of sheep aureus which binds with IgG the RBC, at 4’C-15’C produces wrong way by non-immune incomplete hot-cold lysis mechanism and disrupts opsonization and phagocytosis c.​ Delta - toxin c.​ Leukocidin -​ Small peptide toxin produced by -​ toxin that specifically acts on most strains of S. aureus polymorphonuclear leukocytes -​ A phospholipase which role in disease is not known 3.​ PROTEIN TOXINS d.​ Gamma - toxin and leukocidin -​ Responsible for symptoms during infections -​ Two-component toxin that damages -​ Membrane damaging toxins membrane of susceptible cells -​ Produced separately but act a.​ A - toxin (Alpha toxin) together to damage membranes -​ Expresses 3 proteins: B and C form -​ Best characterized and most potent leukotoxin with poor hemolytic membrane-damaging toxin; major activity whereas A and B are virulence factor hemolytic and weakly leukotoxic -​ Binds to membrane of susceptible -​ Panton and Valentine (PV) cells, its subunits oligomerize to leukocidin distinct from leukotoxin form hexameric rings, a central by gamma locus; has potent pore thru which cellular contents leukotoxicity but non-hemolytic leak -​ PV leucocidin is an important factor -​ Human platelets and monocytes in necrotizing skin lesions such as have high affinity to toxin dermonecrosis wnen injected SC in -​ A complex series of secondary rabbits reactions cause release of eicosanoids and cytokines which e.​ Superantigens trigger the production of inflammatory mediators that 1.​ Enterotoxins produce the symptoms of septic -​ 6 serotypes A, B, C, D, E shock and G -​ Cause diarrhea and vomiting (staphylococcal food poisoning) b.​ B - toxin (Beta toxin) -​ Can cause TSS -​ Sphingomyelinase C damages 2.​ Toxic Shock Syndrome membranes rich in this lipid Toxin (TSST1) MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​weakly related to -​ Coagulase extracellular protein enterotoxin and does not though small fraction is tightly have emetic activity bound on bacterial cell surface and -​ Responsible for 75% of reacts with prothrombin TSS including menstrual -​ Clumping factor is cases; tampon-related TSS fibrinogen-binding determinant on not true infection S. aureus cell surface, sometimes -​ Superantigens stimulate referred to as bound coagulase T-cells without normal antigenic recognition, 2.​ Staphylokinase results -​ Plasminogen activator -​ to release of cytokines in -​ Complex formed between large amounts causing staphylokinase and plasminogen symptoms of TSS -​ Activates plasmin-like proteolytic f. Epidermolytic (exfoliative) toxin - ET activity which dissolves fibrin clot -​ Causes scalded skin syndrome in 3.​ Enzymes neonates with widespread blistering -​ Proteases, lipases, and loss of epidermis deoxyribonuclease (Dnase) and -​ 2 forms: fatty acid modifying enzyme ​ ETA (FAME) ​ ETB -​ FAME important in abscesses -​ Protease activity where it could modify antibacterial -​ Possibly the toxin targets a specific lipids and prolong bacterial survival protein involved in maintaining the -​ First three provide nutrients for integrity of the epidermis bacteria g. Other extracellular proteins 4.​ Hyaluronidase -​ hydrolyzes hyaluronic acid 1.​ Coagulase (cementing substance) -​ Extracellular protein which binds -​ Spreading factor with prothrombin in host to form staphylothrombin which causes the S. EPIDERMIDIS activation of the protease activity of thrombin resulting to conversion of fibrinogen to fibrin and formation of -​ Most important coagulase-negative clot in plasma staphylococci (CNS) which is a -​ Traditional marker for identifying S. common commensal of the skin aureus -​ Major cause of infections -​ Coagulase and clumping factor associated with prosthetic devices separate entities and catheters MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Production of characteristic slime -​ Exudative dermatitis in rabbits and (biofilm) subcutaneous abscesses in older -​ Opportunistic invader animals Cultural and Biochemical Characteristics 7.​ Porcine necrotizing -​ S. aureus coagulase and catalase staphylococcal endometritis (+), S. epidermidis coagulase (-) but catalase (+) -​ Salt tolerant, S. aureus ferments mannitol, S. epidermidis does not S. INTERMEDIUS Epidemiology -​ Epidemiological tracing traditionally -​ Most prevalent in dogs and phage typing but has limitations carnivores Diseases S. HYICUS SUBSP. HYICUS S. AUREUS -​ Exudative epidermitis of swine 1.​ Botryomycosis in horses -​ Thru breaks on the skin -​ Stump of spermatic cord after -​ Moist, greasy exudate on entire castration become infected, body of animal enlarged and sclerotic with pockets -​ Biotin requirement of pus containing granules similar to actinomycosis Diagnosis 1.​ Smears 2.​ Mastitis 2.​ Culture on BAP -​ suppurative lesions in cattle, 3.​ Mannitol salt agar (MSA) organisms colonize tips of teats 4.​ Coagulase 5.​ Deoxyribonuclease 3.​ Tick pyemia in lambs -​ Acute septicemia or bactermia Immunity along with toxemia kills lamb -​ No effective vaccine -​ Ixodes ricinus Antimicrobial Resistance 4.​ Facial or periorbital eczema in 1.​ Beta lactamase sheep 2.​ Methicillin resistant S. aureus (MRSA) or multiple-drug resistant 5.​ Purulent synovitis in poultry -​ Bumblefoot in turkey LESSON 2: STREPTOCOCCUS 6.​ Cutaneous staphylococcosis MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ CHO or polysaccharide Ag found in MORPHOLOGICAL CHARACTERISTICS cell wall or between the cell wall and cell membrane teichoic) -​ Gram (+), non-motile, non-spore forming coccus in pairs or chains, CULTURAL CHARACTERISTICS capsulated -​ Individual cells are round to ovoid, -​ More fastidious organisms require 0.6-1.0 um in diameter enrichment with blood or serum -​ Catalase (-) facultative anaerobe -​ Small, delicate, translucent colonies about 1 mm in diameter Habitat -​ Grow well in milk producing lactic -​ saprophytes in milk, parasites of acid mucous membranes and intestines VIRULENCE FACTORS CLASSIFICATIONS 1.​ Hyaluronic acid capsule interferes 1.​ Sherman with phagocytosis a.​ Pyogenic 2.​ Protein M responsible for virulence -​ pathogenic species -​ type-specific immunity, Inhibits phagocytosis immunotoxic effect on b.​ Viridans polymorphs and platelets -​ alpha/green hemolysis 3.​ Lipoteichoic acid in hair-like fimbrae c.​ Lactic responsible for attachment of -​ associated with milk streptococci to epithelial cells d.​ Enterococcus 4.​ Extracellular products -​ intestinal inhabitant a.​ Hemolysins 2.​ Lancefield -​ Streptolysins O and S responsible for beta -​ Serologically active carbohydrate hemolysis (C substance) which is antigenically -​ Antibodies to Streptolysin different from one species to O good indicator of present another or past infections -​ Six groups – A,B,C,D,E, and N -​ Streptolysin O oxygen -​ Add 14 – F, G, H, K, L, M, O, P, Q, sensitive, streptolysin S is R, S, T, U, V​ not -​ Both toxic for neutrophils and macrophages MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Streptolysin O is protein, S. AGALACTIAE elicits neutralizing antibodies -​ Streptolysin S, peptide, -​ Long chains in secretions from non-antigenic infected udder -​ Brick reddish growth on solid b.​ Streptokinase medium containing starch -​ Fibrinolysin -​ Activates plasminogen to CAMP Test (Christie, plasmin leading to Atkins,Munch-Peterson) digestion of fibrin clots -​ synergistic hemolysis produced by sequential action of staphylococcal c.​ Dnases A, B, C, D sphingomyelinase (B-toxin) and -​ Streptodornase ceramide-binding protein (N-acyl -​ Extracellular enzymes that sphingosine) of Streptococcus assist in production of agalactiae substrates for growth -​ Reduce viscosity of fluid PATHOGENESIS containing DNA (pus) -​ In mammary glands of cows, d.​ Hyaluronidase sheep and goats -​ Promotes spread of -​ Spread thru milker’s hand, infection in tissues contaminated milking machine, mouth of calves e.​ Erythrogenic toxin (A, B, C) -​ Enters thru teats and colonize -​ Low molecular weight mammary glands resulting to proteins inflammation and fibrosis of -​ Group A responsible for adjoining area, milk becomes rashes in scarlet fever alkaline and WBC counts exceeds 500,000/ml -> milk reduced, thin f.​ NADases and watery -​ Kill phagocytes produced -​ To count wbc - comprehensive by some Group A metabolic panel (CMP) streptococci PREVENTION g.​ Proteinase -​ Broad substrate specificity, -​ Vaccination not an effective means produced by group A of controlling streptococci DIAGNOSIS 1.​ Direct smears MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA 2.​ Colony characteristics and -​ Most common cause of wound biochemical test infections in horse -​ Secondary invader of viral infections of upper respiratory tract S. DYSAGALACTIAE of foals and young horse -​ Mastitis in cows -​ Acute, severe mastitis -​ Fibrinous pleuritis, pericarditis and -​ Lancefield group C pneumonia in lambs -​ Often produces a distinct greenish discoloration S. UBERIS PATHOGENESIS -​ Bovine mastitis -​ Infection much less frequent than -​ Does not react in Lancefield Streptococcus agalactiae grouping system -​ Produces hyaluronidase -​ Acute but mild S. EQUISIMILIS -​ Closely related to S. zooepidemicus PATHOGENESIS -​ Most frequent cause of suppurative arthritis in pigs -> lameness, swelling of joints and necrosis of joint surfaces -​ Tonsillar tissues and draining lymph nodes S. ZOOEPIDEMICUS PREVENTION -​ Normal commensal of the skin and -​ Vaccine shown to stimulate upper respiratory tract, tonsils and protective immunity lymphoid tissues of horses -​ Closely related to Streptococcus S. EQUI equi and S.equisimilis PATHOGENESIS -​ Causes strangles, a severe purulent infection of the upper respiratory tract and draining lymph nodes in horses MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Long chains in exudates and fluid cytotoxin produced by cultures microorganism damages -​ Sometimes with definite capsular phagocytes -> extracellular material multiplication of microorganisms -​ Outer surface of organism with -​ Other virulence factors: M protein peach-fuzz like coating of protein and hyaluronic acid capsule -> high under electron microscope rate of intracellular survival CULTURAL AND BIOCHEMICAL SYMPTOMS FEATURES -​ High fever -​ Colonies matt or mucoid -​ Serous nasal discharge -> -​ Matt colonies with irregular surface mucopurulent -> nasopharyngeal folding and look dried -> due to mucosa inflamed and small phage-controlled hyaluronidase abscesses develop in lymphoid action on the hyaluronic acid follicles of soft palate -> capsule submandibular and retropharyngeal -​ O2 sensitive Streptolysin O-like lymph nodes hemolysin produces a wide zone of -​ Abscesses rupture in1-2 weeks and B-hemolysis animals recover quickly and -​ carries R antigen (acid, heat and completely after drainage of trypsin resistant but pepsin purulent material sensitive, cross-reacts with S. -​ Bastard strangles -> formation of zooepidemicus) and M antigen abscesses in thorax and abdomen (provides antiphagocytic action) -> rupture results to death PATHOGENESIS COMPLICATIONS -​ Obligate parasite of family Equidae 1.​ Laryngeal hemiplegia -​ Thru nasal and oral route, 2.​ Guttural pouch empyema ingestion most common portal of 3.​ Purpura hemorrhagica – side effect entry;inhalation of infective droplets of vaccination -​ Incubation period -6 days to 3 weeks or longer IMMUNITY -​ Epithelial cells of oropharynx -> -​ Immunity after recovery from first lesion interiorized -> lymph vaccination drainage to submandibular and -​ Animals can contract the disease retropharyngeal Lymph nodes -> again abscess formation -​ Complement-derived chemotactic DIAGNOSIS factors C3a and C5a) release and attract PMN cells -> powerful 1.​ RIA MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA 2.​ ELISA S. EQUINUS 3.​ Mouse protection test 4.​ Gel diffusion precipitin test -​ Abundant in feces of horses PREVENTION -​ Not known to be pathogenic -​ Heat inactivated bacterin or S. LACTIC M-protein rich extracts -> not useful -​ Avirulent, genetically modified -​ No pathogenic properties but strain stimulates local omnipresent in milk nasopharyngeal antibodies -​ Common milk-souring organism ; short chains S. PORNICUS S. BOVIS -​ cervical lymphadenitis -​ Group E strepiococci -​ Always present in mouth and -​ Swine strangles intestinal tract of cattle -​ Abscessation of mandibular, retropharyngeal and parotid nodes -> jowl abscessation LESSON 3: BACILLUS -​ Almost all are non-pathogenic and S. SUIS saprophytic -​ Most pathogenic is B. anthracis -​ Meningitis and septicemia in young pigs -​ Lancefield group D BACILLUS ANTHRACIS -​ Zoonotic -​ Causes anthrax, milzbrand (German), charbon (French) S. CANIS -​ Herbivores highly susceptible, carnivores and birds resistant -​ Mucous membranes of dogs and -​ Fatal in humans cats -​ Lancefield Group G MORPHOLOGY -​ Metritis and vaginitis in bitches -​ Large, Gram (+) rods, 1um x 3-6 um -​ In cultures, forms long chains which appear as solid filaments because of square ends that fit closely together MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ In tissues, short chains with ends of PATHOGENESIS cells rounded -​ Single capsule enclose organisms ​ Major anthrax enzootic zones in in chain tropics and subtropics such as -​ Spores formed at 15-40’C in the India, Pakistan, Africa, South presence of air -> sporulation America inhibited by high CO2 tension such as carcasses 1.​ Alkaline soil with high nitrogen level -​ Spores central to subterminal and caused by decaying vegetation not swollen 2.​ Alternating period of rain and drought 3.​ Temperatures beyond 5.5 ‘C ​ Source of infection CULTURAL AND BIOCHEMICAL FEATURES 1.​ Soil 2.​ Bone mean and vegetable protein -​ Grows well on most lab media 3.​ Wool and hair -​ Spores germinate at 65’C for 15 4.​ Tannery effluents mins 5.​ Bloodsucking flies and carrion -​ Ground glass-like appearance on eaters surface colonies on agar with irregular margins -> under LPO ​ Infection via the skin and resemble locks of wavy hair known respiratory tract usually by as Medusa-head colonies ingestion of spores -> germination -​ Deep colonies small, ragged and of spores in the mucosa of throat stringy and intestinal tract -> multiplication -​ Biochemically, much less active at site of primary invasion -> than other bacilli lymphatic channel -> lymph nodes -​ Non-motile -> multiplication -> bloodstream -> -​ Capsule made up of polymers of spleen D-glutamic acid and some ​ If splenic clearance exceeded, polysaccharide animal dies -> 80% of organisms in -​ Spores resistant to boiling but killed blood, 20% in spleen by autoclaving ​ Death due to extracellular toxin -​ Resistant to disinfectants and remain viable for more than 50 ​ Toxin complex or holotoxin years -​ Vegetative cells killed at 60’C for 30 1.​ Edema factor (EF) mins and quickly destroyed by -​ Adenylate cyclase -> increases enzymes and putrefactive bacteria intracellular cyclic AMP MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA 2.​ Protective antigen (PA) -​ Often becomes generalized -​ plasma-encoded, necessary for -​ In swine and dogs, localized form biological activity of EF and LF; with pharyngeal involvement and probably a receptor binding gastroenteritis -> inflammatory molecule edema of head and neck -> suffocation 3.​ Lethal factor (LF) 2.​ Generalized anthrax Net effect of holotoxin -​ airborne spores; pulmonary or 1.​ Damage and kill inhalation anthrax; woolsorter’s phagocytes disease 2.​ Increased capillary cell permeability 3.​ Damage clotting mechanism 4.​ Inhibit bactericidal activity of serum DIAGNOSIS Capillary thrombosis -> fluid leaks -​ By methods that release minimum thru damaged endothelium -> blood number of anthrax organisms in the pressure falls -> shock environment; blood samples from ears veins ​ Blocks opsonizing activity of C3 factor of complement -> reduced 1.​ Mc Fadyean’s stain phagocytosis -​ organisms blue, capsules pink ​ Symptoms 2.​ Capsular antigen detected by agar 1.​ Edema gel precipitation test /AGPT known 2.​ Shock as Ascoli test 3.​ Hemorrhaging before death 3.​ Ground glass-like non-hemolytic ​ Peracute form 1-2 hours, acute colonies on BAP -> Medusa-head form less than 24 hours or judge’s wig-type colonies FORMS OF ANTHRAX 4.​ String of pearl test -​ in presence of penicillin, organisms 1.​ Localized anthrax grow with cell wall impairment -> -​ thru wound on skin; cutaneous organisms resemble string of pearls form; malignant carbuncle or pustule 5.​ Bacteriophage (gamma phage) -> -​ More often in humans than in only B. anthracis lysed animals MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA 6.​ Animal test MORPHOLOGY -​ pathogenic in guinea pigs and mice, death within 24 hrs -​ Straight slender rod, 0.4-0.6 um x 2-5 um IMMUNITY -​ Occurs singly in tissues and culture -​ Spores formed after 24-48 hours at -​ Recovered animals have end of rods 2-3x width of the rod permanent immunity -> badminton-racket or -​ Immunization with Sterne’s live, drumstick-like non capsulated, avirulent spore -​ Gram variable, peritrichous flagella vaccine or culture filtrate of avirulent, non capsulated strain CULTURAL CHARACTERISTICS PREVENTION AND CONTROL -​ Colonies in deep agar fluffy, cottony spheres -​ Reportable disease -​ Brush-like effect in gelatin -​ Should be treated, uninfected -​ Does not ferment CHO animals immunized RESISTANCE -​ Highly resistant to sporicidal agents and techniques -​ Boiling kills spores of most strains in 15 mins ANTIGEN AND SEROTYPES -​ glycopeptide antigen, heat labile flagellar or somatic antigen -​ 9 serotypes LESSON 4: CLOSTRIDIUM PATHOGENESIS I.​ TOXIN-FORMING, -​ Found in the soil, common in horse NON-INVASIVE GROUP manure -​ Contamination of wounds and umbilicus especially deep CLOSTRIDIUM TETANI penetrating wound which become necrotic with reduced O2 and -​ Causative agent of tetanus lowered Eh (measure of redox, -​ Best known of all anaerobic measurement of electrical potential spore-forming bacilli expressed in volts) MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Produces 3 toxins -​ Paralytic action on PNS and inactivation of inhibitory nerve 1.​ Tetanospasmin network -> inhibition of protein -​ Tetanospasmin responsible synthesis in brain for characteristic feature of -​ Neuromuscular activity favors tetanus migration of toxin along both motor and sensory nerves 2.​ Tetanolysin -​ Toxin travels up regional motor -​ causes local tissue nerves where tetanus develops first necrosis which is favorable -> spreads upward in opposite for multiplication; hemolytic limbs and subsequently in muscles for RBC and lethal in lab of the trunk (ascending tetanus) animals -​ Tetanus develops first in susceptible motor nerves of the 3.​ Peripherally active non – head and neck then descends to spasmogenic toxin voluntary muscles of forelimbs, upper trunk and hindlimbs -> Tetanospasmin descending tetanus, usually in -​ Two subunits, heavy and light humans and horses, affecting chains which are non-toxic when nictitating membrane, facial and jaw separated muscles causing lockjaw or risus -​ Destroyed by gastric juices, heat sardonicus resistant, poorly absorbed across -​ Shorter incubation period, worse mucous membranes prognosis -​ Extremely potent, LD50 for mice is -​ Non-spasmogenic toxin equivalent to 2 x 10-8 mg -​ Binds gangliosides which are bound to cerebrosides, 2 PORTALS OF ENTRY gangliosides to 1 molecule toxin -​ Reaction difficult to reverse and Ab 1.​ Nails wounds in horses ineffective when toxin is bound 2.​ Castration and docking in lambs -​ Travels along nerve trunk to spinal 3.​ Calving, dehorning, castration and cord nose ringing in cattle -​ Action: prevents the release of 4.​ Autointoxication glycine, transmitter substance 5.​ Castration in swine responsible for inhibitory nerve 6.​ Wound infection in dogs and cats network of spinal cord -> prevents 7.​ Umbilical cord in newborn contraction of muscle when its opposite counterpart contracts -> IMMUNITY continuous stimulation and tetanic spasms of groups of muscles 1.​ Birds – naturally resistant, no Abs, brain has no affinity MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA 2.​ Sheep and goats neutralizing Abs 3.​ Horse, dogs, pigs and human no FORMS antitoxin, power of binding with toxin 1.​ Intoxication 4.​ Hyperimmuned serum from horse, 2.​ Wound infection 1,500 units protective for 2-3 weeks 3.​ Infant botulism – intestinal 5.​ Vaccines colonization -​ 0.4% formalin -> precipitated with aluminum potassium sulfate MORPHOLOGY suspended in saline -​ 3 doses at 3-week intervals -​ Spores oval, centric and excentric -​ Horses: toxoids at 6 to 8-week intervals followed by booster 6-12 CULTURAL AND BIOCHEMICAL months later, then annual booster CHARACTERISTICS TREATMENT -​ Acetic acid major metabolic product of all strains -​ Antitoxin asap in single IV or -​ Non-proteolytic type acidify but do intracisternal dose of 100,000 to not coagulate milk 200, 000 units -​ Proteolytic type slowly curdle milk -​ Large doses of penicillin and partially digest and darken curd -​ All strict anaerobes but not DIAGNOSIS fastidious -​ 6 serotypes, 7 toxin types -​ Characteristic symptoms -​ Drumstick-like spores Strain Hosts Disease -​ Injection to mice A Humans, Botulism, cattles, Forage CLOSTRIDIUM BOTULINUM horses, Poisoning, chicken, Limberneck, -​ Source of potent neurotoxin which Mink causes botulism, a disease B Humans, Botulism characterized by flaccid paralysis Cattle, and eventual death due to Horse, respiratory failure Chicken, -​ First discovered in Belgium from Mink, Foal imperfectly smoked ham C Ducks. Wild Shaker foal birds, syndrome, Human Limberneck, Western MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Lameness associated with duck disease, phosphorus deficiency -> lamsiekte Botulism or lame sickness -​ Toxicoinfectious botulism, toxin in D Cattle Lamsiekte necrotic areas of the body (foal) -> shaker foal syndrome -> E Humans Botulism characterized by dysphagia, F Humans Botulism tremors, weakness, recumbency followed by death G Humans Botulism MECHANISM OF INFECTION BOTULINUM TOXIN -​ Ingestion -> intestinal wall (protected by hemagglutinins from -​ Complex consisting of toxin digestive processes) -> ruminal molecules and hemagglutinin bacteria inactivate substantial moiety quantity of ingested toxin -> -​ Toxins of non-proteolytic strains bloodstream -> peripheral nervous require proteolytic enzymes such system -> binds to gangliosides at as trypsin to fully express its toxic neuromuscular junction -> inside activity surface of cell membrane -> -​ Toxin released during lysis of cells functional change, vesicles containing acetylcholine no longer PATHOGENESIS able to release AC ​ Toxin only affects cholinergic -​ From ingestion of food nerves of the PNS blood-brain contaminated with preformed toxin barrier protect cholinergic nerves -​ From decaying carcass, ingested or ​ Effect is flaccid paralysis which contaminating other food stuffs progresses to involve the respiratory muscles resulting to 1.​ Fly larvae carry toxins to birds that death feed on them ​ Disturbance in vision, locomotion 2.​ Decaying vegetation on edges of difficult, paralysis of the tongue, ponds and lakes -> ducks can pharyngeal paralysis, respiratory develop botulism paralysis 3.​ Offal and fish meals ​ In poultry, nictitating membrane ​ Swine and carnivores resistant to -​ Aphosphorosis causes depraved toxin appetite for decaying carcasses -> occurrence of botulism IMMUNITY MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Homologous antitoxin protective noyvi rams, Black but not universally practiced in birds diseases -​ Polyvalent toxoid (necrotic -​ Polyvalent antitoxin no longer hepatitis in effective once toxin is bound to sheep) nerve membranes Clostridium Blackleg, black chauvoei quarter, Quarter DIAGNOSIS evil, symptomatic anthrax -​ Demo of toxin in serum, intestinal contents and suspected foodstuffs Clostridium Malignant septicum edema, Braxy or bradsot II.​ TISSUE-INVADING, ENTEROTOXIGENIC GROUP Clostridium Ulcerative colinum enteritis or quail ds Clostridia Disease Clostridium lota spiroforme enterotoxemia in Clostridium A Yellow lamb rabbits perfringens disease Clostridium Enterotoxemia in B Lamb dysentery, difficile hamsters Hemorrhagic enteritis of sheep Clostridium Subcutaneous and goats villosum abscesses in cats C Necrotic enteritis, stuck in sheep CLOSTRIDIUM PERFRINGENS D Enterotoxemia – overeating ds, pulp kidney ds -​ Synonym: ​ C. welchii, gas bacillus, E Enterotoxemia in Welch bacillus lambs and calves -​ Five types, A to E, four major lethal toxic Clostridium Red water -​ Spores oval, not much swelling hemolyticu disease, m Hemorrhagic -​ Old cultures pleomorphic, clubbed disease, Inf. types, ballooned cells and filaments icterohemoglobin -​ Capsules in tissues, non-flagellated uria CULTURAL AND BIOCHEMICAL Clostridium Big head in CHARACTERISTICS MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Pulpy kidney disease, overeating -​ Inner zone of complete and outer disease zone of incomplete hemolysis -​ Epsilon toxin which requires trypsin -​ Produces lecithinase or chemotrypsin activation and has (phospholipase C) a permease effect on the intestinal -​ Stormy fermentation of litmus milk mucosa enhancing absorption -> -​ 4 toxins: alpha (phospholipase), results to foci of liquefactive beta, epsilon, iota necrosis, perivascular edema and hemorrhages especially in the PATHOGENESIS meninges -> receptor site on vascular endothelium of the brain -​ Ubiquitous in nature, part of normal -> breakdown of intercellular intestinal flora junctions and escape of fluids -​ Strain A in soil, B-E in intestines -​ Activated epsilon has pressure -​ Most common cause of necrotizing activity which increases blood myositis in horses pressure ​ C. perfringens Type A ​ C. perfringens Type E -​ Alpha toxin in small intestine is -​ Hemorrhagic, necrotic enteritis in absorbed into circulation causing calves massive intravascular hemolysis and capillary damage IMMUNITY ​ C. perfringens Type B -​ Alum precipitated type-specific -​ Lamb dysentery toxoid -​ Beta toxin produces hemorrhagic zones and ulcerations of the small DIAGNOSIS intestines -​ Toxin in intestinal contents ​ C. perfringens Type C -​ Enterotoxemia CLOSTRIDIUM HEMOLYTICUM -​ Beta toxin, labile and denatured by enzymes in the intestines -​ Acute hemorrhagic enteritis in pigs -​ Closely related to C. novyi (type D) -​ Struck or Romney Marsh disease -​ Spores are oval and subterminal, -​ Sheep causes bulging -​ Beta toxin produces necrosis of -​ Motile mucosa in the abomasum and small intestine CULTURAL AND BIOCHEMICAL FEATURES ​ C. perfringens Type D MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Exacting in cultural requirements good anaerobic conditions, medium -​ Culture from liver lesions must contain tryptophan -​ Demonstration of phospholipase C in liver lesions ANTIGENS AND TOXINS CLOSTRIDIUM NOYVI -​ C. hemolyticum, beta toxin only; C. novyi, type B, alpha and beta toxins -​ Novy’s bacillus edematis maligni II PATHOGENESIS -​ Three types: A, B, C MORPHOLOGY -​ Predilection for alkaline water -​ Site of toxin production is liver -​ Tissue destruction caused by -​ Spores oval and subterminal migration of liver flukes which -​ Motile provides suitable microenvironment for germination CULTURAL AND BIOCHEMICAL FEATURES of spores -​ Beta toxin (phospholipase C) -​ More strictly anaerobic and requires causes massive intravascular cysteine in reduced form hemolysis and capillary damage -> hemorrhage into lumen of intestine PATHOGENESIS and Hb in urine -> dark red or port-colored, clear but foamy -> no -​ In soil and intestinal tract of intact RBC herbivores -​ At time of hemoglobinuria, 40 to -​ Multiply in wounds contaminated 50% of hemoglobin destroyed by soil and cause gas gangrene -​ Death caused by anoxemia due to -​ Big head in rams as result of massive destruction of infection of wounds sustained in fighting RBC -​ Alpha toxin damages capillary endothelium at site of invasion, -​ Most characteristic lesion is large brain, muscle, liver, heart -> infarct in liver as a result of elevation of intracellular enzymes occluding thrombosis lactic dehydrogenase and glutamic oxaloacetic transaminase IMMUNITY Black disease – necrotic hepatitis in sheep -​ Alum-precipitated, formalinized whole culture -​ Liver damage from migration of immature Fasciola hepatica DIAGNOSIS MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Alpha and lesser beta toxin -​ Flagellar, somatic and spore -​ Necrotic areas on surface of liver antigens -​ Extensive blood-stained edema -​ Toxins include alpha, hyaluronidase under skin -> black disease and deoxyribonuclease IMMUNITY PATHOGENESIS -​ Alum precipitated, formalinized -​ In soil, unknown if it lives in the soil whole culture and multiplies in the intestine -​ Vaccination before heavy fluke -​ Entry via oral route during grazing activity -> multiplies in the intestine -> lymphatic and blood circulation -> DIAGNOSIS muscle and liver -> dormant until muscle mass becomes altered or -​ Demo of alpha toxin in tissues and damaged exudates -​ May enter thru alveoli of the teeth -​ FAT – fluorescein antibody -​ necrotizing, leukocidic and technique spreading factor of alpha toxin and hyaluronidase promote development of myonecrosis CLOSTRIDIUM CHAUVOEI -​ Area reddish brown to black, crepitant with spongy texture due to -​ Synonym: Clostridium feseri trapped gas, dry on cut surface -​ Blackleg in ruminant -​ Affected area first swollen, painful and crepitant -> sensation lost and MORPHOLOGY skin becomes tighter -​ Spores oval and excentrical IMMUNITY -​ Swelling rods into lemon-shaped structures -​ Formalinized whole culture or anacultures with alum CULTURAL AND BIOCHEMICAL FEATURES DIAGNOSIS -​ Strictly anaerobic 1.​ Organism in heart, liver and -​ Blood or serum favors growth in peritoneal fluid ordinary media 2.​ FAT -​ High requirement for cysteine ANTIGENS CLOSTRIDIUM SEPTICUM MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Ghon-Sachs bacillus, Malignant -​ Cause of swine erysipelas in young edema bacillus pigs -​ Malignant edema DISEASE FORMS MORPHOLOGY 1.​ Diamond skin disease -​ Spore oval, excentrical and swell 2.​ Septicemia cells 3.​ Polyarthritis 4.​ Endocarditis CULTURAL AND BIOCHEMICAL 5.​ Abortion FEATURES ​ In swine, lambs, calves, turkeys, -​ Grows readily on all ordinary media ducks w/ good anaerobic condition ​ Skin lesions in human known as erysipeloid ANTIGENS MORPHOLOGY -​ Somatic and flagellar agglutinogens -​ Gram (+) but easily decolorized and PATHOGENESIS stain unevenly -​ Rough forms exhibit long filaments -​ Common in soil and intestinal tract -​ No spores, no flagella -​ In lambs thru wounds, umbilicus -​ Cell wall does not contain and abomasal lining (braxy or DL-diaminopimelic acid bradsot) (differentiated from L. -​ Wound infection -> malignant monocytogenes) edema -> swellings are soft and pit on pressure -> large amounts of CULTURAL CHARACTERISTICS gelatinous exudate, muscular tissue dark red but contains little or no gas -​ Colonies on serum or blood agar -​ Parablackleg bacillus tiny, clear and glistening -​ 4 toxins -​ On BAP, first a greenish ​ alpha discoloration and later a definite ​ beta clearing ​ gamma -​ Bottle brush-like in gelatin ​ delta -​ 22 serotypes, 1 and 2 most commonly found in cases of LESSON 5: ERYSIPELOTHRIX septicemia and in tonsils -​ Protective antigen is a glycoprotein -​ Swine rotlauf bacillus PATHOGENESIS MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA DISEASES IN SWINE become necrotic -> dries -​ Resistant to drying, smoking, into dense scabs and peel pickling and salting off -> bleeding if removed -​ Common in areas with alkaline soil too soon -​ Carried in tonsils and reticuloendothelial tissue 3.​ Severe septicemic phase -​ Stress such as excessive heat and -​ Increased levels of SGOT humidity predisposing factors and marked hypoglycemia -​ Ubiquitous in nature -​ Increased RBC destruction, -​ Organism shed in urine, feces, decreased Hb and PCV saliva, vomitus -​ Late stages spleen enlarged and pulphase ​ Route of infection -​ Hemagglutinating activity 1.​ Oral -​ Neuramidase associated 2.​ Skin scarification with generalized coagulopathy -> thrombi in -​ Facultative intracellular parasite blood vessels, fibrin in with high rate of survival in pig joints, heart valves and neutrophils -> subsequent killing of muscles phagocytes -> blocking of RES due -​ High fever due to to depletion of phagocytes endotoxin, a glycoprotein which produces shock ​ Forms effect 1.​ Acute - high fever 41.1’C 4.​ Chronic form -​ Deep red patches on skin -​ Vegetative endocarditis -> particularly in ears, mitral valves eroded and abdomen, inside of legs covered with fibrin deposits -​ Spleen and lymph nodes -> functioning seriously enlarged and reddened impaired -​ Stomach and intestines inflamed, hemorrhagic 5.​ Arthritic form -​ Kidneys with ecchymotic -​ Older animals, sequel to hemorrhages more acute forms of -​ High mortality disease -​ Joint enlarged and painful 2.​ Less severe form -> reluctant to move , gaits -​ Urticarial skin lesions -> stilted, growth stunted red rhomboidal blotches in -​ Synovial lining hypertrophy abdomen-> with villous projections into diamond-shaped (diamond joint space skin disease) -> areas MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Erosion of cartilage, increase in synovial fluid DIAGNOSIS with high neutrophil content -​ As disease advances, Hog cholera Erysipelas organism difficult to isolate -​ More severe in vaccinated Lethargic Bright and alert swine and with autoantibodies (rheumatoid Do not eat Contine to eat factor) Diarrhea Not common DISEASES IN SHEEP unchanges or Spleen enlarged, -​ Polyarthritis wedge-shaped bluish-red -​ Route of entry: docking and infarct castration Not often found Stomach highly DISEASES IN CATTLE inflamed, dark, -​ Arthritis: tibio-tarsal, stifle, carpal bluish joint Lymph node Lymph node not hemorrhagic congested DISEASES IN BIRDS -​ Bluecomb, cyanotic skin Petechiae in Ecchymoses -​ Droopy, develop diarrhea and die subserosa -​ Massive hemorrhage and petechiae in muscles of breast and legs -​ Human erysipeloid, human erysipelas caused by hemolytic DISEASES IN LAB ANIMALS streptococci sp. -​ White mice highly susceptible DISEASES IN AQUATIC ANIMALS LESSON 6: LISTERIA -​ Crocodile, bottle-nosed dolphins -​ Only one species pathogenic for IMMUNITY warm-blooded animals and humans, Listeria monocytogenes -​ Protective immunity: serum and cell-mediated MORPHOLOGY -​ Growth-agglutination test Wachstumsprobe test -​ Gram +, non-acid fast, small rods -​ First attenuated vaccine by Pasteur -​ Shows slight clubbing, diphtheroid and Thiullier appearance, coccoid forms found -​ EVA erysipelas vaccine avirulent -> -​ Peritrichous flagella with tumbling attenuated vaccine motility -​ Killed vaccines MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Gram (–) in young cultures and -​ Central nervous system signs almost entirely in old culture include unilateral ataxia and meningitis CULTURAL AND BIOCHEMICAL -​ Microabscesses found in brain FEATURES stem -​ Keratoconjunctivitis and -​ Grows on most ordinary media ophthalmitis described in cattle and though growth never abundant sheep -​ Deep colonies minute points with -​ Abortion in cow and ewes without narrow zone of beta-hemolysis neural manifestations; organism in -​ Surface colonies small, flat, aborted fetus and uterus bluish-white, transparent -​ In chickens and turkeys, takes -​ In gelatin inverted fir tree septicemic form; necrotic foci of the -​ Unlike E. rhusiopathiae, , it liver and myocardium produces catalase -​ Visceral or septicemic form with liver necrosis in rabbits, guinea ANTIGENS pigs, chinchilla -​ 15 O antigens, 5 H antigens; 16 PATHOGENESIS serotypes, 14 subtypes -​ Ubiquitous in nature, in animal and MODE OF INFECTION human feces -​ Major factor of survival is pH, below -​ Mode of infection of neural and pH 5, survival is poor visceral form different -​ More heat tolerant than most -​ In neural form, infection via non-spore forming bacteria branches of trigeminal nerve and -​ In silage, tonsils of swine the eye, nose and oropharynx -​ Facultative intracellular parasite -​ In visceral form, ingestion is major mode of infection 1.​ Cell wall surface protein internalin -​ Most infections exogenous interacts with E-cadhedrin, a protein receptor on epithelial PATHOGENICITY surface, facilitating phagocytosis into phagocytic and non-phagocytic -​ Disease is listeriosis, neural form cells known as “circling disease” 2.​ Bacterium enclosed in phagosome, -​ Neural form most common in produces hemolysin listeriolysin O ruminants (thiol-activated cytolysin that can -​ Outbreaks occur in feedlots, lyse cholesterol-containing associated with feeding of silage membranes of eukaryotic cells) -​ Increase in iron consumption which lyses membrane of thought to contribute to listeriosis phagosome allowing the bacteria to MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA escape into the cytoplasm of the host cell 3.​ Bacteria proliferate and induce polymerization of host cell actin which moves them to the cell membrane where they push against the cell membrane and form TREATMENT protrusions called filopods 4.​ Filopods ingested by adjacent -​ Of little value macrophages and other cells, -​ Chloramphenicol, tetracycline, released and cycle repeats itself sulfonamides, penicillin -​ In humans, erythromycin and ISOLATION AND CULTIVATION ampicillin -​ Difficult to recover from brain -​ Ground brain stored at refrigerator temperature (cold enrichment) and recultured for as long as 12 weeks -​ Grows well on ordinary media but routinely isolated on blood agar -​ Primary growth stimulated by 5-10% CO2 -​ Smooth colonies approx. 2 mm in diameter, round, entire, glistening and bluish by transmitted light, with narrow zones of beta-hemolysis -​ Small, Gram (+) rods, occur singly, in pairs or in short chains resembling diptheroids and streptococci -​ Resistant to drying -​ Can survive for months in food, straw, soil and shavings IMMUNITY -​ Most part depends on T-cell mediated activation of macrophages -​ Role of humoral response not clear -​ Immunization not widely practiced MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Produces diphtheric inflammation of bladder, ureters, kidney, pelvis LESSON 7: CORYNEBACTERIUM -​ Bacillary pyelonephritis of cattle, specific pyelonephritis of cattle, -​ Pleomorphic, Gram-positive rods infectious pyelonephritis of cattle that stain irregularly -​ Occur in angular and palisade MORPHOLOGY AND STAINING arrangements (fence of stakes) -​ Club-shaped swellings at one or -​ Large diphtheroid bacillus, 0.5 x 1.3 both ends, hence the name to 2.6 um Corynebacterium (club bacterium) -​ Short, stumpy rods that are a little -​ No spores, non-acid fast, thicker at one end than at the other non-motile -​ In exudates and cultures, organism -​ Pathogenic species are facultative in clumps anaerobes -​ Non-motile, non-sporeforming, non-capsulated Reclassification of some species as: -​ Strongly Gram-positive, with bars and granules when stained with 1.​ Corynebacterium equi methylene blue -​ Rhodococcus equi -​ Pili present but fewer in C. renale 2.​ Corynebacterium pyogenes CULTURAL AND BIOCHEMICAL -​ Actinomyces CHARACTERISTICS 3.​ Corynebacterium suis -​ Growth commonly enhanced by -​ Eubacterium addition of blood or serum ​ C. diphtheriae (human diphtheria) is 1.​ C. renale type species, others termed as -​ colonies opaque, ivory-colored and diphtheroid bacilli dull with uneven margins Corynebacterium renale Group 2.​ C. pilosum -​ C. renale (type I) -​ cream colored to pale yellow, -​ C. pilosum (type II) circular. Opaque, above 1 mm in -​ C. cystitidis (type III) diameter CORYNEBACTERIUM RENALE 3.​ C. cystitidis -​ white, entirely circular, semitranslucent and pinpoint -​ Most frequently isolated from bovine mastitis, ureteritis, -​ In culture, growth slightly cloudy pyelonephritis with with granular sediment -​ Predominantly in female animals MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ C. renale in litmus milk: reduction in IMMUNITY the bottom of the tube then formation of soft curd which is -​ Serum antibody response in cows slowly digested; medium alkaline at with pyelonephritis and urethritis all times; medium separates into but not with cystitis alone dark red fluid and heavy sediment -​ Protective response of host -​ Only C. renale produces caseinase; ineffective and untreated animals multiplies in bovine urine producing seldom recover ammonia from urea DIAGNOSIS ANTIGENS 1.​ Characteristic symptoms -​ Antigenic pilus protein different in 2.​ Blood clots and bits of necrotic each of the 3 species tissue in urine – Gram stain EPIZOOTIOLOGY AND PATHOGENESIS ANTIMICROBIAL SUSCEPTIBILITY - Each species highly adapted to bovine -​ Sensitive to penicillin, streptomycin, and ovine urinary tract kanamycin, erythromycin and -​ Transmission via contaminated polymyxin B urine droplets, adherence -​ Penicillin in large doses antibiotic pilus-mediated of choice -​ Penetration and colonization of UT from adherence to aging epithelial CORYNEBACTERIUM cells PSEUDOTUBERCULOSIS -​ C. renale most frequently isolated from cases of pyelonephritis -​ C. ovis, Preisz-Nocard bacillus -​ C. pilosum occurs in urine and -​ Causes caseous lymphadenitis vagina of healthy cows causing prevalent in sheep and goats cystitis and vaginitis occasionally -​ Also in horses, camels, mules, -​ C. cystitidis causes severe rarely in cattle and humans hemorrhagic cystitis followed by -​ Suppuration and necrosis of lymph pyelonephritis; commensal on nodes prepuce of bulls; disease involves urinary bladder including one or MORPHOLOGY AND STAINING both ureters and one or both kidneys; -​ Pleomorphic rod, so short and often -​ Ovine posthitis (pizzle rot) believed mistaken for a coccus; rod form in to be caused by irritating effect of caseous pus from lymph nodes ammonia released by urease from -​ Non-spore forming, non-motile C. renale in the prepuce -​ Non-acid fast -​ MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Ability to survive and produce CULTURAL AND BIOCHEMICAL abscesses in sheep and goats due CHARACTERISTICS to: -​ Grows slowly on all ordinary media ​ Phospholipase D -​ Takes several days to reach -​ increases vascular maximum size; fully developed permeability have papilliform centers surrounded ​ Heat=stable pyogenic factor by concentric rings that parallel the -​ attracts leukocytes irregular margin ​ Large amounts of surface lipids -​ Colonies grayish or yellowish with -​ toxic for phagocytes dry and dry surface -​ Cell wall with high lipid content -​ Disease primarily a wound -​ Slight hemolysis on blood agar infection; starts with local inflammation at site of entry -> ANTIGENS proceed to regional lymph node -> enlarges and become filled with pus 2 Serotypes which is green and odorless, ​ Serotype I initially thin then thick and caseous, -​ predominates in sheep and gaots, arranged in concentric layers infrequent in cattle resembling an onion ​ Serotype 2 -​ Causes ulcerative lymphangitis in -​ in befalo and cattle horses, similar to cutaneous glanders (farcy) in horses; nodules -​ Exotoxin is phospholipase D which appear on legs and break down to causes intravascular hemolysis, form ulcers which exude thick necrosis, pulmonary edema and greenish pus usually mixed with shock; acts synergistically with blood, usually around the fetlock; phospholipase C of Rhodococcus lesions fill with cicatricial tissue; equi spread thru lymphatic system EPIZOOTIOLOGY AND PATHOGENESIS ​ Pigeon fever -​ large painful abscesses in -​ caseous lymphadenitis commonly the pectoral, lower spreads directly fro open abdominal and inguinal abscesses and enters thru skin regions; lesions in adult abrasions horses develop slowly, -​ Ulcerative lymphangitis on fetlocks sometimes recur after of horses and pectoral abscesses opening and draining; (pigeon fever) in horses generalization results in -​ Facultative intracellular parasite death -​ Rarely isolated from cattle MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Cystitis and pyelonephritis in sows IMMUNITY MORPHOLOGY AND STAINING -​ Detection of antibodies thru agglutination test, toxin -​ Pleomorphic, slim, Gram positive neutralization in mice and rabbits, -​ Does not form spores, non-motile antihemolysin inhibition test, -​ Exhibits branching and Chinese hemolysin inhibition test, double letter patterns immunodiffusion technique and ELISA CULTURAL AND BIOCHEMICAL -​ No proven vaccination to give high CHARACTERISTICS level of protection -​ Optimum growth under anaerobic DIAGNOSIS conditions at 37’C -​ Colonies on BAP gray, tiny and 1.​ Lesions shiny after 24 hours, but as they 2.​ Dry, scaly colonies which produce mature becoe flattened with gray hemolysis on BAP matt appearance -​ No hemolysis on BAP, enrichment ANTIMICROBIAL SUSCEPTIBILITY with tryptic soy, urea enhances growth -​ Sensitive to penicillin, ampicillin, chloramphenicol, erythromycin, EPIZOOTIOLOGY AND PATHOGENESIS gentamycin and tetracycline; in vivo responses poor -​ Most male pigs in enzootic areas carry organism in their prepuce, DISEASES IN HUMANS rarely in females -​ Colonization of bladder leads to -​ Localized adenopathy and cystitis hepatomegaly accompanied by -​ Urine contains clots of blood and fatigue and myalgia purulent material -​ Infection of bladder can ascends to kidneys causing urethritis and CORYNEBACTERIUM BOVIS pyelonephritis -​ In milk from healthy udders, DIAGNOSIS reproductive tract of cows and bulls; occasional primary pathogen 1.​ Blood and pus in urine of breeding in outbreaks of mastitis sows 2.​ Smears of urine sediment and pus Genus Eubacterium showing Gram positive, slender -​ C. suis coryneform organism MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA 3.​ Urine aerobic and anaerobic culture CULTURAL AND BIOCHEMICAL on BAP and CNA agar – Gram FEATURES positive anaerobic coryneform -​ Grows well on all ordinary media ANTIMICROBIAL SUSCEPTIBILITY (not fastidious) -​ Colonies 1 cm in diameter, raised, -​ Penicillin moist, translucent and regular outline; white then become rose pink especially those grown on LESSON 8: RHODOCOCCUS potato -​ Grows poorly in milk -​ Belongs to the order -​ Catalase and urease positive, Actinomycetales consisting of 9 cytochrome c negative soil-associated species that -​ Does not ferment CHO, reduces produce a red pigment nitrate, does not form indole, is not -​ Fast forming hemolytic -​ Only R. equi has been reported to -​ Produces phospholipase and cause lesions in animals cholesterol oxidase that reacts with (particularly in horse) phospholipase D of C. -​ Purulent pneumonia, mesenteric pseudotuberculosis, the beta toxin lymphadenitis and arthritis in foals of S. aureus and the hemolysin of and lesions similar to tuberculosis L. monocytogenes to completely in the cervical lymph nodes of hemolyze sheep, cattle and rabbit swine and cattle Rhodococcus equi RC > rapid presumptive test for id -​ Causative agent of purulent of R. equi pneumonia in foals ANTIGENS MORPHOLOGY AND STAINING -​ Polysaccharide capsule -​ Large organism, pleomorphic -​ 4 groups, 14 serotypes forming bacillary and coccoid forms -​ Serotypes; klase ng antibody -​ Coccoid on solid media, bacillary in fluid, sometimes short chains EPIZOOTIOLOGY AND -​ Metachromatic granules (iba ang PATHOGENESIS kulay kesa sa original) usually demonstrated if grown in milk -​ Acquired from the soil -​ Gram positive, variably acid fast, -​ Gut contents and feces of stains readily with other ayes herbivores -​ Non-spore forming, has a lamellar -​ Heat resistant, killed at 60'C for 1 polysaccharide capsule hour (pasteurized), resists extreme MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA pH (acidic), 0.01% sodium azide, 0.5% formaldehyde, sunlight and IMMUNITY desiccation (drying) -​ Route of infection in foals is respiratory tract -​ Involves cell-mediated immune ​ Entry into alveoli→ responses phagocytosis by -​ Surface component inhibit macrophages -> massive bactericidal mechanisms of PMNS infiltration of macrophages -​ Antibody production measured by and multinucleated giant precipitin reaction, complement cells into alveolar space -> fixation, agglutination, indirect foci of alveolar necrosis in hemagglutination and ELISA which bacteria-laden Antibodies present in Serum of macrophages undergo normal mares and passively degeneration -> transferred to their foals granulomatous response of -​ Poor antibody responses the lung > massive invasion of PMNs DIAGNOSIS (polymorphonuclear neutrophils) -> suppurative 1.​ Recognized on basis of source bronchopneumonia with isolate prominent abscesses 2.​ Gram staining reaction -​ Pneumonia in foals 2 to 5 months 3.​ Pleomorphism and older 4.​ Pinkish, mucoid, spreading colonies 5.​ Catalase and urease positivity Manifestations: 6.​ Lack of fermentative activity on -​ Anorexia, nasal discharge, arthritis CHO and diarrhea 7.​ Equi factor test of Prescott -​ 64% mortality confirmatory -​ Lymphadenitis, with lymph nodes abscessed -​ Transtracheal aspirates and -​ In contrast to strangles cultures with Gram staining of great (Streptococcus equi), lymph nodes value of the head seldom involved -​ Selective medium: Nalidixic acid, -​ Pneumonia in foals most common novobiocin, cycloheximide and but also found in internal abscesses potassium tellurite (NANAT in pleurisy medium) > colonies are black In swine -​ infection of submandibular and ANTIMICROBIAL SUCEPTIBILITY cervical lymph nodes, sometimes in association with the tubercle bacilli MICRO102A - VETERINARY BACTERIOLOGY AND MYCOLOGY LEC DOCTOR OF VETERINARY MEDICINE 2ND SEMESTER A.Y. 2025 – 2026 DR. JOCELYN MIRANDA -​ Sensitive to penicillin G, doxycycline, erythromycin, lincomycin, gentamycin, neomycin and streptomycin -​ Combination of erythromycin and rifampicin or penicillin; penicillin and gentamycin DISEASES IN HUMANS -​ With AIDS or undergoing immunosuppressive therapy for malignant neoplasms