Gram-Positive: Staphylococcus Report PDF

GRAM-POSITIVE: STAPHYLOCOCCUS BIO 125 - GROUP 2 INTRODUCTION STAPHYLOCOCCUS a genus of Gram-positive bacteria Classification family Staphyloccocaceae order Bacillales Normal Human Microflora (Skin) When it enters internal tissues and the bloodstream, it may cause infections (Taylor & Unakal, 20...

GRAM-POSITIVE: STAPHYLOCOCCUS BIO 125 - GROUP 2 INTRODUCTION STAPHYLOCOCCUS a genus of Gram-positive bacteria Classification family Staphyloccocaceae order Bacillales Normal Human Microflora (Skin) When it enters internal tissues and the bloodstream, it may cause infections (Taylor & Unakal, 2022). MORPHOLOGY SHAPE SIZE “cocci” round 0.5 – 1.0 μm in diameter ARRANGEMENT clusters short chains STRUCTURES thick peptidoglycan layer capsule (in some) no flagella / pili Images retrieved from: https://upload.wikimedia.org/wikipedia/commons/d/d3/Staphylococcus_aureus_VISA_2.jpg https://med.stanford.edu/news/all-news/2023/04/cancerbacteria/_jcr_content/main/image.img.476.high.jpg/Staphylococcus-epidermidis.jpg pairs nonmotile; spreading & comet formation ID Gram staining Catalase Test SPECIFIC STAPH STRAIN: Coagulase Test Novobiocin Sensitivity Test Image retrieved from: https://microbeonline.com/ezoimgfmt/i0.wp.com/microbeonline.com/wpcontent/uploads/2022/06/Identification-flow-chart-for-Staphylococcus-saprophyticus.png? ezimgfmt=ng%3Awebp%2Fngcb2%2Frs%3Adevice%2Frscb2-1&ssl=1&w=779 ANTIGENIC STRUCTURE Cytoplasmic Membrane Peptidoglycan Layer protective layer for surface protein attachment Teichoic Acid lipoteichoic acid (LTA) & wall teichoic acid (WTA) Protein A capture IgG molecules prevent phagocytosis Clumping Factor binds to blood plasma protein fibrinogen Capsule makes bacterial surface slippery inhibit phagocytosis Image retrieved from: https://d45jl3w9libvn.cloudfront.net/jaypee/static/books/9789351523802/Chapters/image s/164-1.jpg TOXINS Hemolysins lyse red blood cells Ex. Alpha Toxin Leukolycins lyse white blood cells Exfoliative Toxins split intracellular bridges in stratum granulosum Enterotoxins cause vomiting & diarrhea Toxic Shock Syndrome Toxin-1 cause hypotension, capillary leakage & shock ENZYMES Coagulase coats bacterial cells with fibrin making it antiphagocytic Fibrinolysin dissolve fibrin clots Hyaluronidase hydrolyzes hyaluronic acid Penicillinase inactivates penicillin Lipase hydrolyzes lipids Nuclease hydrolyzes DNA PATHOGENESIS S. aureus - Multifactorial pathogenesis - “Molecular Koch's Postulates” approach expression of many cell surfaceassociated and extracellular proteins Surface proteins that promote colonization of host tissues Factors that probably inhibit phagocytosis Toxins that damage host tissues and cause disease symptoms Adherence laminin fibronectin - present on epithelial and endothelial surfaces; component of blood clots fibrinogen/fibrin binding proteins promotes attachment to blood clots and traumatized tissue Avoidance of Host Defenses - Capsular polysaccharide, Protein A, Leukocidin PATHOGENESIS 1) Epithelial breach, dissemination from biofilm formed on indwelling medical devices 4) Invasion of tissue cells mediated by MSCRAMM surface proteins 5) Subsequent abscess formation impacted by specific surface proteins, toxins, and exoenzymes 2) Elimination of immune cells in the bloodstream via cytolytic toxins 3) Phagocytic activity of Kupffer cells Image source: https://www.researchgate.net/publication/348934977_Pathogenicity_and_virulence_of_Staphylococcus_aureus REGULATION OF VIRULENCE DETERMINANTS In S. aureus, the production of virulence determinants such as cell wall adhesins and exotoxins during the growth cycle is controlled by global regulators such as SarA and agr. sensitive to environmental signals consist of a sensor histidine kinase and a response regulator PATHOLOGY Causes diseases through: Formation of biofilm S. aureus Release of exotoxins Biofilm Collection of bacteria encased in exopolysaccharide layer. Process: 1. Adhesion 2. Aggregation 3. Maturation 4. Dispersion Image source: https://www.mdpi.com/2079-6382/12/1/12 PATHOLOGY Causes diseases through: Formation of biofilm Toxic shock syndrome toxin type 1 - act as superantigen - stimulates immune response to produce high amounts of IL-2 and TNF. Leukocidin - pore-forming toxin - causes leukocyte destruction and tissue necrosis Beta-hemolysin - destroy RBC and liberates hemoglobin S. aureus Release of exotoxins Exfoliative toxin - damages desmoglein-1 - loss of connection between keratinocytes Enterotoxin - targets enterocytes within epithelial lining of GI tract - intestinal cells lose its absorption function PATHOLOGY Causes diseases through: Biofilms form in: Vascular devices Urinary catheters Prosthetic valves and joints S. epidermidis Formation of biofilm Effects: wound infections endocarditis inflammations PATHOLOGY Causes diseases through: S. saprophyticus Formation of biofilm Biofilms form in: Urinary catheters Effect: urinary tract infections infections Release of urease enzyme Urease will: breakdown urea into CO2 and 2NH3 cause pH to increase forms struvite crystals Effects: bacterial growth obstruct urinary tract CLINICAL FINDINGS S. aureus Image source: https://skinsight.com/skinconditions/furunculosis-boil/ Image source: https://www.cdc.gov/groupastrep/diseases -public/impetigo.html Image source: https://www.dermatologyinc.com/cellulitis Furuncle Impetigo Cellulitis reddish bumps filled with pus grows larger until they rupture and drain red, itchy sores with yellow scabs painful, red, and tender skin skin may blister scabbing occurs Image source: https://www.nhs.uk/conditions/skinabscess/ Abscess red lump containing pus feel painful and warm soft when touched CLINICAL FINDINGS Image source: https://my.clevelandclinic.org/health/disea ses/22408-pyomyositis Pyomyositis swollen muscles due to abscess causes difficulty in moving Image source: https://www.britannica.com/science/osteo myelitis Osteomyelitis destroys porous bone and bone marrow causes swelling and redness S. aureus Image source: https://radiopaedia.org/articles/septicarthritis Septic arthritis destructive arthropathy permanent damage to joint CLINICAL FINDINGS Image source: https://emedicine.medscape.com/article/9 69239-overview Toxic shock syndrome causes fever, chills, rash and hypotension Image source: https://www.healthline.com/health/scalded -skin-syndrome#symptoms Ritter’s disease red, tender skin broken blisters peeling skin S. aureus Image source: https://www.careinsurance.com/blog/healthinsurance-articles/gastroenteritis-know-the-symptomscauses-and-treatment Gastroenteritis causes body ache, watery diarrhea, and vomiting CLINICAL FINDINGS Image source: https://www.readersdigest.co.uk/health/he alth-conditions/top-10-tips-for-living-witha-catheter Catheter-associated disease S. epidermidis Image source: https://www.aljazeera.com/news/2022/7/1/ uks-contaminated-blood-scandal-inquiryall-you-need-to-know Image source: https://www.youtube.com/watch? v=09TUnwxfW54 Blood cultures contamination Prosthetic infections CLINICAL FINDINGS Image source: https://www.newsmedical.net/health/What-is-ChronicCystitis.aspx Cystitis pain or burning feeling when urinating blood in the urine pelvic pain S. saprophyticus Image source: https://www.verywellhealth.com/pyeloneph ritis-1124158 Pylenophritis pain when urinating blood in the urine pain in lower back or side DIAGNOSTIC LAB TEST A medical professional will usually do the following to detect a staph infection: Conduct a physical examination. Looks for skin sores or inflamed areas Take a sample for analysis Looking for bacteria in blood, urine, skin, infected material, or nasal secretions Other tests should be suggested Recommendation of echocardiography TREATMENT Antibiotics - Antibiotics for antibiotic-resistant staph infections must be injected intravenously (via a vein) Cefazolin, Nafcillin, Oxacillin, Daptomycin, and Linezolid Vancomycin - for serious staph infection Wound drainage - Incision into the sore to drain the accumulated fluid Device removal - If your infection includes a medical device, such as a urinary catheter, cardiac pacemaker, or artificial joint, the device should be removed as soon as possible. SEVERAL MECHANISM OF DRUG RESISTANCE B-lactamase B-lactam ABX MSSA Antibiotics: Oxacillin S. aureus Nafcillin SEVERAL MECHANISM OF DRUG RESISTANCE mecA gene S. aureus methicillin efficacy PBP2a MRSA Antibiotics: Vancomycin Clindomycin Doxycycline TMP-SMX SEVERAL MECHANISM OF DRUG RESISTANCE vanA gene peptidoglycan VRSA Antibiotics: Linezolid S. aureus vancomycin efficacy SEVERAL MECHANISM OF DRUG RESISTANCE gyrase S. epidermidis vs. S. saprophyticus stabilizes DNA + susceptibility test stabilizes DNA - susceptibility test (due to mutations in the DNA) NSSE gyrase NRSS NOVOBIOCIN SUSCEPTIBILITY TEST S. saprophyticus vs S. epidermidis Mlynarczyk-Bonikowska et al. (2022) SEVERAL MECHANISM OF DRUG RESISTANCE aureus (MSSA) B-lactamase (in blaZ gene) - Blactam antibiotics treated w/ oxacillin, nafcillin (MRSA) mecA gene - (SCCmec) - PBP2a low methicillin efficacy treated w/ vancomycin, doxycycline, clindomycin, tmp-smx (VRSA) vanA gene - alters peptidoglycan - low vancomycin efficacy treated w/ linezolid epidermidis B-lactamase (in blaZ gene) - B-lactam antibiotics treated w/ oxacillin, nafcillin mecA gene - (SCCmec) - PBP2a - low methicillin efficacy treated w/ vancomycin, doxycycline, clindomycin, tmp-smx vanA gene not detectable novobiocin-sensitive (affects DNA gyrase) Summary saprophyticus B-lactamase (in blaZ gene) - B-lactam antibiotics treated w/ oxacillin, nafcillin mecA gene - (SCCmec) - PBP2a - low methicillin efficacy treated w/ vancomycin, doxycycline, clindomycin, tmp-smx vanA gene not detectable novobiocin-resistant (mutations in the DNA cause resistance) EPIDEMIOLOGY skin/mucuos membrane S. aureus half of all adults (15% in nares) Mode of Transmission: person-to-person contact fomites risk for health workers/pers ons who use needles regularly EPIDEMIOLOGY nosocomial blood infections S. epidermidis people w/ prosthetic valves, cardiac devices, catheters Mode of Transmission: person-to-person contact fomites neonates EPIDEMIOLOGY UTI/urinary discomfort (women) S. saprophyticus 60% recurrent UTI gastrointestinal tract of pigs and cows Mode of Transmission: eating pork and beef sexual transmission THANK YOU! REFERENCES Davies, M., & Pollitt, E. (2016, October 3). Spotlight on Grants: The motility of Staphylococcus aureus. Microbiologysociety.org. https://microbiologysociety.org/blog/spotlight-on-grants-the-motility-of-staphylococcusaureus.html Ehlers, S., & Merrill, S. (n.d.). Staphylococcus saprophyticus Infection. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK482367/#:~:text=saprophyticus%20has%20resistance%20to%20antibiotic,t he%20previously%20mentioned%20antibiotics%2C%20S. Foster, T. (1996). Staphylococcus (S. Baron, Ed.). PubMed; University of Texas Medical Branch at Galveston. https://www.ncbi.nlm.nih.gov/books/NBK8448/#:~:text=Staphylococci%20are%20Gram%2Dpositive%20cocci%20ab out%200.5%20%E2%80%93%201.0%20%CE%BCm%20in Herman-Bausier, P., Labate, C., Towell, A. M., Derclaye, S., Geoghegan, J. A., & Dufrêne, Y. F. (2018). Staphylococcus aureus clumping factor A is a force-sensitive molecular switch that activates bacterial adhesion. Proceedings of the National Academy of Sciences, 115(21), 5564–5569. https://doi.org/10.1073/pnas.1718104115 Kong, C., Neoh, H., & Nathan, S. (2016). Targeting Staphylococcus aureus Toxins: A Potential form of Anti-Virulence Therapy. Toxins, 8(3), 72. https://doi.org/10.3390/toxins8030072 REFERENCES Kumari, R. (2021, October 18). Staphylococcus aureus-Epidemiology, Pathogenesis & Treatment. Microbiology Notes. https://microbiologynotes.org/staphylococcus-aureus-epidemiology-pathogenesis-treatment/ Mayo Clinic. (2017). Staph infections - Diagnosis and treatment - Mayo Clinic. Mayoclinic.org. https://www.mayoclinic.org/diseases-conditions/staph-infections/diagnosis-treatment/drc-20356227 Młynarczyk-Bonikowska, B., Kowalewski, C., Krolak-Ulinska, A., & Marusza, W. (2022). Molecular Mechanisms of Drug Resistance in Staphylococcus aureus. International Journal of Molecular Sciences, 23(15), 8088. https://doi.org/10.3390/ijms23158088 Ninja Nerd. (2021, October 21). Staphylococcus: aureus, epidermidis, saprophyticus [Video]. YouTube. https://www.youtube.com/watch?v=6BkqWKOG8E0 Sharif, S., Singh, M., Kim, S. J., & Schaefer, J. (2009). Staphylococcus aureusPeptidoglycan Tertiary Structure from Carbon-13 Spin Diffusion. Journal of the American Chemical Society, 131(20), 7023–7030. https://doi.org/10.1021/ja808971c REFERENCES Taylor, T. A., & Unakal, C. G. (2022). Staphylococcus Aureus. PubMed; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK441868/#:~:text=S. van Dalen, R., Peschel, A., & van Sorge, N. M. (2020). Wall Teichoic Acid in Staphylococcus aureus Host Interaction. Trends in Microbiology. https://doi.org/10.1016/j.tim.2020.05.017 Votintseva, A. A., Fung, R., Miller, R. R., Knox, K., Godwin, H., Wyllie, D. H., Bowden, R., Crook, D. W., & Walker, A. S. (2014). Prevalence of Staphylococcus aureus protein A (spa) mutants in the community and hospitals in Oxfordshire. BMC Microbiology, 14(1), 63. https://doi.org/10.1186/1471-2180-14-63