Bacteriology Lecture Finals Lesson 1.pdf

BACTERIOLOGY LECTURE S.Y. ‘24 - ‘25 | SEM 1 FINALS WEEK 1: NEISSERIA 1.0 NEISSERIA General Characteristics: 1.1 Pathogenic Neisseria spp....

BACTERIOLOGY LECTURE S.Y. ‘24 - ‘25 | SEM 1 FINALS WEEK 1: NEISSERIA 1.0 NEISSERIA General Characteristics: 1.1 Pathogenic Neisseria spp. Virulence Factors: Receptors for human transferrin Most Neisseria spp. are: Capsule (N. meningitidis) Aerobic Pili (fimbriae) Non-motile Cell membrane proteins Non-spore forming Lipooligosaccharide (LOS) or endotoxin Gram negative diplococci (except: N. elongate, Immunoglobulin A (IgA) protease that cleaves N. weaver, N. bacilliformis) IgA on the mucosal surface All species are: Cytochrome oxidase 1.2 Neisseria gonorrhoeae Catalase negative (except: N. elongate subsp., Nitroreducens, N. bacilliformis) Human–only natural host Agent of the sexually transmitted disease Many Neisseria spp. are CAPNOPHILIC, they (gonorrhea) can grow anaerobically if alternative electron Primary site: acceptors (ex. nitrites) are available. ❖ Urethra Natural habitat: mucous membranes of ❖ Endocervix respiratory and urogenital tracts. ❖ Anal Canal Primary human pathogens: N. gonorrhoeae, N. ❖ Pharynx meningitidis ❖ Conjunctiva Pathogenic Neisseria spp. are: Epidemiology: Fastidious organisms Most commonly transmitted through sexual Sensitive to unfavorable environmental contact conditions Asymptomatic carrier–primary reservoir Requires iron for growth National reportable disease ❖ Confirmed cases must be reported to Neisseria weaveri: state health laboratories Commensal in the upper respiratory tract of Highest rates of infection dogs. ❖ Men and women between age of 20 All other Neisseria spp. are considered and 24 opportunistic pathogens. Gonorrhea is second to Chlamydia trachomatis of confirmed sexually transmitted bacterial infection in the US. PPT | LECTURE BACTE LEC FINALS PAGE 1  BACTERIOLOGY LECTURE S.Y. ‘24 - ‘25 | SEM 1 FINALS WEEK 1: NEISSERIA Clinical Infections: Gonococcal arthritis Incubation period: ❖ Purulent arthritis ❖ Approx. 2 to 7 days ❖ Result of disseminated gonococcal Gonorrhea bacteremia ❖ Acute pyogenic infection of the: Extragenital infections urogenital tract, pharynx, conjunctiva ❖ Oropharyngeal infections: pharyngitis of the eye Anorectal infections Less likely infections: ❖ Most common in men who have sex ❖ Disseminated infections with men ❖ Anal canal ❖ 30% to 60% of women with genital infection can get anorectal infection Clinical Infections in Men: ❖ Rectal pain or bloody stools possible Incubation period: Most infections are asymptomatic or have ❖ Approx. 2 to 7 days non-specific symptoms Transmitted only by intimate sexual contact Disease in Newborns Asymptomatic gonococcal infection is ❖ Ophthalmia neonatorum - gonococcal uncommon. eye infection occurs during vaginal 90% of infected men show symptoms of acute delivery through an infected birth infection. canal. Common manifestation: ❖ If not treated immediately, newborn ❖ Acute urethritis blindness can occur ❖ Dysuria ❖ Infection is preventable with the 10% are asymptomatic application of eye drops at birth Complications: (erythromycin). ❖ Prostatitis ❖ Every infant at birth, must be treated. ❖ Epididymitis ❖ Urethral stricture Specimen Collection and Transport: Rectal culture Clinical Infections in Women: ❖ Insert swab 4 to 5 cm into the anal Common site of infection: canal ❖ Endocervix Oral/pharyngeal Symptoms: Eye ❖ Dysuria Blood/joint fluids ❖ Cervical discharge When possible, notification of pending ❖ Lower abdominal pain Neisseria samples should be made to the 50% are asymptomatic laboratory. Complications: Preferred swabs for specimen collection: ❖ Pelvic inflammatory disease ❖ Dacron or rayon ❖ Sterility ❖ Calcium alginate and cotton swabs ❖ Ectopic pregnancy or are inhibitory to N. gonorrhoeae (DO ❖ Fitz-Hugh-Curtis Syndrome NOT USE) ❖ Direct plating of specimens to Clinical Infections in other Sites: gonococcal-selective media gives Blood-borne dissemination (