Bacteria: Gram Negative and Beyond

Neisseria meningitidis

Neisseria meningitidis

Which gram negative diplococci is transmitted by droplets (respiratory and throat secretions) and causes meningitis and meningococcemia?

Neisseria meningitidis

Which gram negative diplococci is a carrier state in the nasopharynx of 5% of the population (naturally immune)?

• causes meningitis

military recruits and college students

Which populations are common/concerning for Neisseria meningitidis infection with meningitis and meningococcemia?

Neisseria meningitidis

Which gram negative diplococci causes sudden onset of fever, headache, stiff neck, vomiting, petechial rash, and myalgias and has vaccination and chemoprophylaxis?

meningitis/meningococcemia

Which condition involves sudden onset of fever, headache, stiff neck, vomiting, petechial rash, and myalgias though infection by a gram negative diplococci?

Neisseria gonorrhoeae

Which gram negative cocci infects through sexual or vertical transmission causing sudden onset of burning/frequent urination, purulent discharge, swelling and erythema in genitals, vaginal itching/burning (often co-infected with chlamydia)?

Complications

• Pelvic inflammatory disease (PID)

• Neonatal conjunctivitis

• Septic arthritis

gonorrhea

Which condition involves sudden onset of burning/frequent urination, purulent discharge, swelling and erythema in genitals, vaginal itching/burning though infection by a gram negative cocci?

Moraxella catarrhalis

Which gram negative cocci causes otitis media and COPD exacerbations and is a carrier state in the upper respiratory tract in 28-100% of humans in the first year of life, and 1-10.4% in adults?

airborne droplet

What route is Moraxella catarrhalis transmitted?

• causes otitis media, COPD exacerbations

Vibrio cholera

Which enteric tract gram negative bacilli causes watery diarrhea (rice water) without cell invasion and causes cholera, with vaccination available for travelers?

fecal-oral

What route is Vibrio cholera transmitted (contaminated water)?

• causes abrupt onset of watery diarrhea (rice-water)

Escherichia coli (E. coli)

Which enteric tract gram negative bacilli causes watery diarrhea without cell invasion and causes:

• UTIs

• Neonatal meningitis (at birth/first 28 days of life)

• Gram-negative sepsis (hospitalized patients)

• Nosocomial (hospital-acquired) pneumonia

Escherichia coli (E. coli)

What bacteria causes watery diarrhea without cell invasion from these common risk foods: undercooked hamburger, unpasteurized beverages, raw cheeses?

gut

Where is E. coli located in the body as part of normal flora?

Escherichia coli (E. coli)

Which enteric tract gram negative bacilli is transmitted through fecal-oral, urethral migration, or aspiration routes and is a common cause of UTIs?

Enterotoxigenic Escherichia coli (ETEC)

Which enteric tract gram negative bacilli causes watery diarrhea without cell invasion through fecal-oral route causes traveler’s diarrhea (rice water, self-limited)?

Shigella sp.

Which enteric tract gram negative bacilli causes bloody diarrhea with mucus and fever?

• never part of normal gut flora

fecal-oral

What route is Shigella spp. transmitted?

• contaminated water

Nontyphoidal Salmonella sp.

Which enteric tract gram negative bacilli causes bloody diarrhea, fever, nausea/vomiting, abdominal pain?

• most common cause of bacterial enterocolitis in US

• never part of normal gut flora

zoonotic

What route is Nontyphoidal Salmonella spp. transmitted?

• turtles, undercooked eggs, chickens

Salmonella typhi

Which enteric tract gram negative bacilli causes fever, headache, bacteremia and disseminates to liver, gallbladder, spleen? tdiarrhea with systemic invasion?

• never part of normal gut flora

• can become chronic carrier (Typhoid Mary)

• Travel Vaccines are available

fecal-oral

What route is Salmonella typhi transmitted?

• contaminated water or food

• humans are the only reservoir

Yersinia enterocolitica

Which enteric tract gram negative bacilli causes fever, headache, bacteremia, and diarrhea and spreads from small intestine to underlying lymphoid tissue?

• most commonly affects young individuals (5-15yo)

fecal-oral

What route is Yersinia enterocolitica transmitted?

• contaminated water or food

Campylobacter jejuni

Which enteric tract gram negative bacilli causes bloody diarrhea, headache, fever, abdominal cramps?

• more common in children

• transmitted by poultry/unpasteurized milk/contaminated water

fecal/oral/zoonotic

What route is Campylobacter jejuni transmitted?

• contaminated water/unpasteurized milk

• poultry

Helicobacter pylori (H. pylori)

Which enteric gram negative bacilli is the most common cause of duodenal ulcers and chronic gastritis?

• second leading cause of gastric (stomach) ulcers behind NSAIDs

• Unknown route of transmission

• Many endoscopy medical professionals acquire this bacteria

Bacteroides sp.

Which enteric gram negative bacilli is normal flora of GI and upper respiratory and common cause of anaerobic infections (sepsis, peritonitis, abscesses)?

• Most common post-op infection most common following bowel surgery

Fusobacterium sp.

Which enteric gram negative bacilli is normal flora of GI and upper respiratory and causes:

• periodontal disease

• aspiration pneumonia

• otitis media

• abdominal/pelvic abscesses

Klebsiella pneumoniae

Which nosocomial gram negative bacilli is normal flora of colon and mouth and causes:

• sepsis

• UTIs in hospitalized patients (nosocomial)

• pneumonia (currant jelly sputum) - alcohol use disorder

person-to-person

What route is Klebsiella pneumoniae transmitted in hospital-settings?

• not airborne

alcohol use disorder patients

Which population is common/concerning for Klebsiella pneumoniae infection with pneumonia (currant jelly sputum)?

• usually transmitted in hospital settings

Proteus mirabilis

Which nosocomial gram negative bacilli is normal flora of colon, found in soil and causes UTIs (nosocomial and community-acquired)?

Enterobacter sp.

Which nosocomial gram negative bacilli is normal flora of colon and causes hospital-acquired infections by invasive procedures?

Serratia sp, Acinetobacter sp

Which nosocomial gram negative bacilli are part of normal flora, found in soil and water, and cause hospital-acquired infections through invasive procedures?

Pseudomonas aeruginosa

Which common nosocomial gram negative bacilli is normal flora in the colon and skin of 10% of patients and is resistant to many antibiotics, causing:

• pneumonia

• UTIs

• wound infections (osteomyelitis, burn infection, surgical wounds)

• sepsis via IV lines

• endocarditis

• malignant external otitis - elderly diabetic patients

Pseudomonas aeruginosa

Which nosocomial gram negative bacilli is transmitted via medical devices and hands of health care workers and causes:

• pneumonia

• UTIs

• wound infections (osteomyelitis, burn infection, surgical wounds)

• sepsis via IV lines

• endocarditis

• malignant external otitis - elderly diabetic patients

elderly diabetic patients

Which population is common/concerning for Pseudomonas aeruginosa infection with malignant external otitis (otitis externa migrates to mastoid bone)?

burns
endocarditis
pneumonia
sepsis
external malignant otitis
UTI
diabetic osteomyelitis

What conditions are frequently caused by Pseudomonas aeruginosa? (BE PSEUDO)

Haemophilus influenzae

Which respiratory tract gram negative bacilli is a common cause of otitis media and chronic bronchitis (non-encapsulated strains) transmitted by airborne droplet?

Type B: meningitis, epiglottitis, septic arthritis - Vaccination Available

Bordetella pertussis

Which respiratory tract gram negative bacilli causes pertussis (whooping cough) transmitted by airborne droplet?

Vaccination Available

Legionella pneumophila

Which respiratory tract gram negative bacilli causes Pontiac Fever and Legionnaires’ Disease transmitted through aerosolized contaminated water?

• Pontiac Fever: flu-like with sudden onset and sudden resolution

• Legionnaires’ Disease: very high fevers and severe pneumonia

Yersinia pestis

Which zoonotic tract gram negative bacilli causes plague through contact with contaminated fluid or tissue of infected animal or inhalation of droplets (person-to- person)?

• rodents harbor disease, fleas are vectors that carry to humans

• high suspicion of patient with high fever camping in Southwest US

• Can be fatal

Francisella tularensis

Which zoonotic tract gram negative bacilli causes high fever and ulceroglandular reaction (ulcer at site of invasion and high fever) from handling infected rabbits, tick bites, deerfly bites?

Brucella sp

Which zoonotic tract gram negative bacilli causes Brucellosis from direct contact with infected meat/ingestion of milk products → undulant fever?

Pasteurella multocida

Which zoonotic tract gram negative bacilli causes wound and bone/joint infections from cat/dog bites?

Chlamydia trachomatis

Which obligate intracellular gram negative bacilli causes chlamydia infection of eyes and genitals?

• conjunctivitis, urethritis, cervicitis, pelvic inflammatory disease, epididymitis, lymphogranuloma venereum

• Complications: Reactive arthritis syndrome, Perihepatitis

Chlamydia psittaci

Which obligate intracellular gram negative bacilli causes fever of abrupt onset, pronounced headache, and dry cough from birds, infection by inhaling dust from feathers or dried feces?

psittacosis

What condition involves fever of abrupt onset, pronounced headache, and dry cough?

• usually a recent history of bird exposure

• infection can also be asymptomatic

bird handlers

Which population is common/concerning for Chlamydia psittaci infection with psittacosis?

• fever of abrupt onset, pronounced headache, and dry cough in otherwise healthy patient

Chlamydia pneumoniae

Which obligate intracellular gram negative bacilli causes bronchitis and pneumonia?

Rickettsia rickettsi

Which obligate intracellular gram negative bacilli causes fever and rash of palms and soles transmitted by tick bite?

patients in North Carolina, Tennessee, Missouri, Arkansas, and Oklahoma

Which population is most common/concerning for Rickettsia rickettsi infection by tick bite with Rocky Mountain Spotted Fever (RMSF)?

Bartonella henselae

Which obligate intracellular gram negative bacilli requires cat bite or scratch causing regional lymph node enlargement, low grade fever/malaise, and rash?

• “cat scratch fever”

• usually self-limited

• Complications: bacteremia and endocarditis

Treponema pallidum

Which gram negative spirochete causes painless ulcers marking syphilis, transmitted through sexual contact or vertical transmission?

• always test during pregnancy due to vertical transmission

Borrelia burgdorferi

Which gram negative spirochete is transmitted via tick bite to produce the classic bullseye rash of Lyme disease?

• Northeast, Midwest, and Northwestern US

• Most common tick-borne illness in the US

Haemophilus ducreyi

Which gram negative bacilli is transmitted sexually and through skin-to-skin contact causes chancroid - painful skin ulcer and inguinal lymphadenopathy with ulceration?

• US cases are low, seen more in other countries

Mycobacterium tuberculosis

Which acid-fast bacteria is transmitted via inhaled respiratory secretions and causes tuberculosis (TB) latent or active disease of the lungs?

• ¼ of world population is infected with TB bacteria

• cell-mediated immunity → PPD injection local skin swelling/redness

Mycobacterium leprae

Which acid-fast bacteria is transmitted via inhaled respiratory secretions and causes leprosy (Hansen’s disease)?

Nontuberculous Mycobacteria spp.

Which acid-fast bacteria is transmitted via inhalation or ingestion and causes lung infections in immunocompromised patients?

• NTM or mycobacteria other than tuberculosis (MOTTs)

• rare in healthy immunocompetent people

• usually infects those on chemotherapy, low CD4 counts

  • mycobacterium avian-complex (MAC) disease

Mycoplasma pneumoniae

Which bacteria without cell walls is transmitted via respiratory droplets and causes mild, self-limited bronchitis and pneumonia?

• gradual onset fever, sore throat, malaise, dry hacking cough (mild symptoms)

• number one cause of “Walking Pneumonia” in teens/adults

Ureaplasma urealyticum

Which bacteria without cell walls causes urethritis (lower urinary tract infection) and is:

• normal flora of the GU tract

• transmitted via sexual contact

Actinomyces israelii

Which gram positive anaerobe bacilli that looks like fungi causes hard, nontender swelling that drains pus through sinus tracts and is:

• normal flora of the oral cavity

• transmitted via broken tissue

Nocardia asteroides

Which gram positive/acid fast aerobe that looks like fungi causes lung infection, nodules, empyema (pus in pleural cavity) in immunocompromised hosts and may disseminate to the body:

• transmitted via inhalation or traumatic inoculation (contaminated water/soil contact with damaged skin)