Neisseria by Dr. Rakesh Prasad Sah
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This document provides information on the bacteria Neisseria gonorrhoeae and Neisseria meningitidis. It discusses their classification, characteristics, pathogenesis, diagnosis and treatment. Key points include: - They are Gram-negative diplococci within the family Neisseriaceae. N. meningitidis is encapsulated while N. gonorrhoeae is not. - N. meningitidis is a common cause of bacterial meningitis while N. gonorrhoeae causes the sexually transmitted infection gonorrhea. - Diagnosis involves culture, antigen detection and PCR. Treatment for gonorrhea is typically ceftriaxone or ciprofloxacin along
Neisseria by Dr. Rakesh Prasad Sah
- 1. By Dr. Rakesh Prasad Sah Assistant Professor Microbiology
- 2. Kingdom: Bacteria Phylum: Proteobacteriacea Class: Betaproteobacteria Order: Neisseriales Family: Neisseriaceae Genus: Neisseria Species: gonorrhoeae meningitidis lactamica,etc CLASSIFICATION
- 3. INTRODUCTION & HISTORY: Discovered Neisseria gonorrhoeae (1879) Albert stain Mycobacterium lepraeAlbert Ludwig Sigesmund Neisser
- 5. CONTAINS TWO IMPORTANT PATHOGENS Nesseria meningitidis Nesseria gonorrhoeae
- 6. IMPORTANT DIFFERENCE BETWEEN N.gonorrhoeae & N. meningitidis N.meningitidis N. gonrrhoeae Note:both can be differentiated by biochemical tests using serum sugar I have got an antibiotic resistant plasmid I have got a polysaccharide capsule
- 7. Meningococci Gonococci Capsulated Non capsulated Lens shape Kidney shape ( G for Gonococci and G looks like Kidney shape) Ferments both Glucose and Maltose (M for Meningococci and M for Maltose) Ferments only Glucose (G for Gonococci and G for Glucose) Extra/ Intracellular Mostly Intracellular ( Can live within Neutrophils)
- 8. NEISSERIA MENINGITIDIS (Meningococcus) Gram negative oval/spherical cocci 0.6 to 0.8 µm in size Arranged in pairs (adjacent sides flattened) Bean shaped Encapsulated Non motile, non spore forming Shape of Neisseria meningitidis
- 9. CULTURAL CHARACTERISTICS Media used: non selective media: Bloodagar Chocolateagar Mueller-Hinton starch casein hydrolysate agar Selective media Modified Thayer-MartinAgar Colony characteristics Color: Bluish grey Shape: Round Size: About 1mm Surface: Smooth Elevation: Convex Opacity: Transluscent Consistency: Butyrous
- 10. BIOCHEMICAL TESTS • Oxidase positive • Catalase positive • Ferments glucose and maltose with acid production • Doesn’t ferment lactose, sucrose and fructose • Nitrate negative • Colistin resistant • Gamma-glutamyl aminopeptidase positive • DNAase Positive
- 11. Virulence factors • Antigens • Capsular polysaccharide • 13 serogroups (A, B, C, D, W 135, X, Y, Z, H, K & L) • Used in vaccine • Serogroups A, B, C, Y, W 135 for about 90% of the epidemics • Antiphagocytic in nature • Outer membrane proteins • 5 classes • Serogroups further subdivided into 20 serotypes Protein I (por)- it is a porin & helps in adherence. Protein II (opa)- helps in adherence. Protein III (rmp)- it is associated with protein I.
- 12. • Pili – helps in meningeal invasion • Toxin • Endotoxin • Lipid A part of lipopolysaccharide • Induces septicemic shock • Enzyme • IgA protease – cleaves the IgA antibodies present in the respiratory mucosa.
- 13. Epidemiology • Reservoir and habitat • Upper respiratory tract of humans • Transmission • Direct contact and air borne droplets • Close contact with infectious person • Family members • Day care centers • Military barracks • Prisons and • Other institutional settings • Incubation period – 1 to 7 days • Carriage • 5 – 30% of normal persons may harbor meningococci in nasopharynx 5 lakh cases, out of which 10% die
- 14. Inhalation of contaminated droplets Adherence of organis to nasopharyngeal mucosa Local invasion and spread from nasopharynx to meninges through blood stream (directly along perineural sheath of olfactory nerve,cribriform plate to subarachnoid space) In meninges, organsims are internalised into phagocytic cells They replicate and migrate to subepithelial spaces Incubation period : 3-4 days PATHOGENESIS (STEPS)
- 15. CLINICAL FEATURES Febrile illness : Mild and self limiting Pyogenic meningitis : High fever, stiff neck, Kernig’s sign, severe headache, vomiting, photophobia, chills Meningococcemia : acute fever with chills, malaise, Waterhouse- frederichsen syndrome, DIC Other Syndrome : Pneumonia, arthritis, urethritis, respiratory tract infection
- 16. Hemorrhage in the adrenal glands in Waterhouse- Fridericksen syndrome Meningococcal disease is favoured by defieciency of the terminal complement components (C5-C9)
- 17. -Signs of meningitis seen - Characteristic Rash is seen : Fever + Hypotension + Headache + Tachycardia + Petechial rash Meningococcal septicemia
- 18. Gram staining : Pink colonies showing diplococci: Since Gram –ve Media : Thayer Martin media Muller Hilton Agar LABDIAGNOSIS Microbiology Biochem Pathology CSF Sample Divide sample in 3 sample bottles and Sendto
- 21. Direct Meningococcal Antigen Detection in CSF by: Latex Agglutination Report: within one hour to direct the antimicrobial therapy. Definitive diagnosis by culture is essential to apply the infection control measures
- 22. Culture Media • Blood agar • Chocolate agar • Selective medium – Modified Thayer-Martin medium with vancomycin, colistin and nistatin to avoid contamination. Growth characteristics • Oxygen requirement • Aerobic and facultative anaerobic • Temperature • Optimum growth at 370C • Growth promoted by 5 – 10% CO2 • Colony morphology • 1 – 2 mm diameter, convex, grey, translucent, non pigmented and
- 24. Biochemical reactions • Oxidase positive and catalase positive • Ferments glucose and maltose with production of gas but not sucrose or lactose
- 25. PROPHYLAXIS a. Chemoprophylaxis : Rifampicin Minocycline Ciprofloxacin b. Vaccination: A vaccine containing capsular polysaccharide of serotypes A and C : for infants below 2 years A quadrivalent vaacine constituted by polysaccharides of serotypes A,C,Y and W-135 : for children and adults conjugate vaccine: polysaccharide antigen is conjugated to diptheria toxoid
- 26. -Meningococcal conjugate vaccine -Vaccine includes Serotype A,C,Y & W but not against B serotype since its capsule is poorly immunogenic VACCINE
- 28. Introduction • causes the sexually transmitted disease gonorrhoea. •first described by Neisser in 1879 in gonorrheal pus. •resembles meningococci very closely in many properties.
- 29. -Gram-ve, non capsulated -Kidney shape -Ferments only glucose -Mostly intracellular -MC in females but is mostly asymptomatic -More severe in males -DOC:3RD GENERATION CEPHALOSPORINS
- 30. . Culture characters: - Enriched media: Chocolate agar - Selective media: Modified Thayer Martin (Chocolate agar + antibiotics) . 5-10% CO2
- 31. 1) Outer membrane protein 2) Pili : Virulence 3) Lipopolysaccharide 4) Capsular polysaccharide : Not responsible for symptoms 5) Lactoferin and transferrin VIRULENCE FACTORS Same as Meningococci
- 32. PATHOGENICITY: Source of infection: 1. Asymptomatic carriers 2. Patients Mode of infection: 1. Venereal infection (sexual contact) 2. Nonvenereal infection
- 33. Mechanism of pathogenesis Gonococci adhere to epithelial cells of urethra or other mucosal surface through pili penetrate through the intercellular space reach the sub epithelial connective tissue & causes inflammation Leads to clinical manifestations Incubation period: 2-8 days.
- 34. Disease A) In men: The disease starts as an acute urethritis with a mucopurulent discharge extends to the prostate, seminal vesicles & epididymis In some it may become chronic urethritis leading to stricture formation The infection may spread to the periurethral tissues, causing abscesses & multiple discharging sinuses (Watercan perineum)
- 35. Water can perineum Urethral Discharge
- 36. B) In women: The initial infection is urethritis & cervicitis but vaginitis does not occur in adult female (vulvovaginitis can occur in prepubertal girls) The infection may extend to Bartholin’s glands, endometrium & fallopian tubes causing Pelvic Inflammatory Disease (PID) Rarely peritonitis may develop with perihepatic inflammation (Fitz-Hugh-Curtis syndrome)
- 38. C) In both the sexes: Proctitis, pharyngitis, conjunctivitis, bacteraemia which may lead to metastatic infection such as arthritis, endocarditis, meningitis, pyemia & skin rashes. D) In neonates: Opthalmia neonatorum (a nonvenereal gonococcal conjunctivitis in the newborn) results from direct infection during passage through birth canal.
- 40. LABORATORY DIAGNOSIS Specimens collected: A) In men: a) Acute infection- Urethral discharge b) Chronic infection- iii) i) Morning drop ii) Discharge collected after prostatic massage Centrifuged deposit of urine B) In women: i) Urethral discharge ii) Cervical swabs
- 41. C) In both the sexes: Blood, CSF, synovial fluid, throat swab, rectal swab & material from skin rashes. Transport: If there is delay in processing than the specimens should be sent in “ Stuart’s medium”.
- 42. Methods of examination: A) Direct microscopy: 1. Gram staining: Smear provides a presumptive evidence of gonorrhea in men. Gram negative diplococci are found. But it is unreliable in women.
- 44. B) Culture: Media used: Colony morphology: Gram’s smear: Reveals Gram negative cocci in pairs with adjacent sides concave. Biochemical reactions:
- 45. C) Serology: Complement fixation test, Precipitation, Passive agglutination, Immunofluorescence, Radioimmunoassay.(uses whole-cell lysate,pilus protein and lipopolysaccharide antigen)
- 46. TREATMENT: Previously Penicillin was drug of choice but resistance developed rapidly. Penicillin resistant is due to production of penicillinase enzyme & the strains are called as penicillinase producing Neisseria gonorrhoeae (PPNG). Now Ceftriaxone or Ciprofloxacin plus
- 47. PROPHYLAXIS: Early detection of cases, Tracing of contacts, Health education, General measures,
- 48. NONGONOCOCCAL (NONSPECIFIC) URETHRITIS Urethritis due to causative agents other than gonococcus. Etiology: a) Bacteria- Chlamydia trachomatis Mycoplasma urealyticum Ureaplasma urealyticum b) Parasites- Trichomonas vaginalis c) Viruses- Herpes simplex Cytomegalovirus d) Fungi- Candida NGU can be a part of Reiter’s syndrome- a clinical condition characterized by urethritis, arthritis & conjunctivitis.
- 49. STEP TO PG-MD/MS -DR.AKIF A.B