Batterjee Medical College

Dr. Manal El Said Head of Microbiology Department Aerobic Gram-Negative Cocci

Batterjee Medical College Dr. Manal El Said Head of Microbiology Department Neisseria

Batterjee Medical College - Meningitis (inflammation the meninges of the brain or spinal cord) - Meningococcemia. Neisseria meningitidis (Meningococcus) Diseases Characteristics Gram-negative "kidney-bean" diplococci. Oxidase-positive. Large polysaccharide capsule. One of the three classic encapsulated pyogenic bacteria (Streptococcus pneumoniae and Haemophilus influenzae are the other two). Habitat and Transmission Habitat is the human upper respiratory tract Transmission is via respiratory droplets.

Batterjee Medical College Pathogenesis Neisseria meningitidis (Meningococcus) The organism reaches the meninges via the bloodstream. Endotoxin in cell wall causes symptoms of septic shock. IgA protease produced. Capsule is antiphagocytic. Deficiency in late complement components recurrent meningococcal infections. The characteristic skin rash (purpura) of meningococcal septicemia, caused by Neisseria meningitidis

Batterjee Medical College Laboratory Diagnosis Gram-stained smear and culture. Oxidase-positive colonies on chocolate agar. Ferments maltose in contrast to gonococci, which do not. Neisseria meningitidis (Meningococcus)

Batterjee Medical College Laboratory Diagnosis Neisseria meningitidis (Meningococcus) N. meningitidis - proper streaking and growth on blood agar plate. Round, moist, glistening & convex colonies

Batterjee Medical College Laboratory Diagnosis Neisseria meningitidis (Meningococcus) Suc - Lac - Mal + Glu +

Batterjee Medical College Treatment Penicillin G (no significant resistance). Neisseria meningitidis (Meningococcus) Vaccine contains capsular polysaccharide of strains A, C, Y & W-135. One form of the vaccine contains the polysaccharides coupled to a carrier protein (diphtheria toxoid) and one contains only the polysaccharides. Rifampin or ciprofloxacin given to close contacts to decrease oropharyngeal carriage. Prevention

Batterjee Medical College Neisseria gonorrhoeae (Gonococcus) Diseases Characteristics Gonorrhea. Neonatal conjunctivitis Pelvic inflammatory disease. Gram-negative "kidney-bean" diplococci. Oxidase-positive. Insignificant capsule.

Batterjee Medical College Pathogenesis Habitat and Transmission Habitat is the human genital tract. Transmission in adults is by sexual contact. Transmission to neonates is during birth. Organism invades mucous membranes inflammation. Endotoxin weaker than that of meningococcus less severe disease when bacteremiaoccurs. IgA protease & pili are virulence factors Neisseria gonorrhoeae (Gonococcus)

Batterjee Medical College Laboratory Diagnosis Neisseria gonorrhoeae (Gonococcus) Gram-stained smear and culture. Organism visible intracellularly within neutrophils in urethral exudate. Oxidase-positive colonies. Gonococci do not ferment maltose (meningococci do). Left: Neisseria gonorrhoeae Gram stain of pure culture; Right: Neisseria gonorrhoeae Gram stain of a pustular exudate.

Batterjee Medical College Laboratory Diagnosis Neisseria gonorrhoeae (Gonococcus)

Batterjee Medical College Treatment Neisseria gonorrhoeae (Gonococcus) Ceftriaxone for uncomplicated cases. Tetracycline added for urethritis caused by Chlamydia trachomatis. High-level resistance to penicillin is caused by plasmid- encoded penicillinase. Low-level resistance to penicillin is caused by reduced permeability and altered binding proteins.

Batterjee Medical College Prevention Neisseria gonorrhoeae (Gonococcus) No drug or vaccine. Trace contacts and treat to interrupt transmission. Treat eyes of newborns with erythromycin ointment or silver nitrate to prevent conjunctivitis.

Batterjee Medical College Small coccobacillary gram-negative rod It causes : -Otitis media & sinusitis in children. -Bronchitis & pneumonia in older people with chronic obstructive pulmonary disease It is found only in humans It transmitted by respiratory aerosol. Moraxella catarrhalis

Batterjee Medical College Dr. Manal El Said Head of Microbiology Department Anaerobic Gram-Negative Cocci

Batterjee Medical College Veillonella parvula is an anaerobic gram-negative diplococcus It is a normal flora of the mouth, colon & vagina. It is a rare opportunistic pathogen that causes abscesses of the sinuses, tonsils & brain It is usually in mixed anaerobic infections. Veillonella