Gram Negative Disease

Meningitis

inflammation of the meninges of the brain and spinal cord

1. Streptococcus pneumonia (actually gram positive)
2. Neisseria meningiditis
3. Hemophilius influenza
4. Listeria monocytogenes (actually gram positive)

What bacteria cause meningitis?

Meningococcal meningitis

An inflammation of the meningeal coverings of the brain and spinal cord; can be highly contagious.

Neisseria meningitidis
-serotype C most common

What causes Meningococcal meningitis?

Transmitted by droplets

How is Meningococcal meningitis transmitted?

1. Classic triad= fever, nuchal rigidity, and a change in mental status
2. Chills, headache, photophobia, N, V, and neck/back pain very common
3. Petechial rash beginning at lower extremities
4. May develop seizure and coma

Clinical presentation of Meningococcal meningitis

1. Brudzinski sign
2. Kernig sign

Physical exam of Meningococcal meningitis

1. Blood culture and lumbar puncture immediately
-CSF may appear purulent, high protein, low glucose, many WBCs, gram - diplococci seen
2. Order a CT before the lumbar puncture if increased intracranial pressure is suspected
3. May see papilledema with fu

Diagnostics of Meningococcal meningitis

1. Antibiotics ASAP
- 2 to 50= vancomycin + 3rd generation cephalosporin
- >50= vancomycin + ampicillin + 3rd generation cephalosporin
2. IV dexamethasone if S. Pneumonia revealed on SF
3. Prophylaxis for close contacts
-rifampin 2 doses, or ciprofloxacin

Treatment of Meningococcal meningitis

1. 10-15% mortality rate
2. 11-19% have serious long term sequelae including hearing loss, loss of limb, brain damage, and CNS damage
*best prognosis with early detection and initiation of antibiotics

Meningococcal meningitis prognosis

1. Quadrivalent conjugate vaccine for adults
2. MenB vaccine for younger patients

Meningococcal meningitis prevention

Neisseria gonorrheae
Co-pathogen= Chlamydia trachomatis
Most commonly seen in teens and young adults

What causes gonnococcal/chlamydial infections?

Sexual contact- invasion of mucus membranes

How are gonnococcal/chlamydial infections spread?

1. Dysuria (serous or milky discharge)
2. Over 1-3 days, pain increases, discharge becomes profuse, yellow, and creamy
3. May have primary infection of pharynx or rectum
4. May be asymptomatic in chlamydia

Clinical presentation of gonnococcal urethritis

Cervicitis

What is gonnococcal urethritis most frequently associated with?

1. May progress to prostatitis
2. May progress to epididymitis
3. Long standing disease may cause urethral stricture

gonnococcal urethritis prognosis

1. Dysuria
2. Urinary frequency and/or urgency
3. Purulent urethral or vaginal discharge
4. May be asymptomatic
*most often symptomatic after menses
*uterine cervix is the most common site

Clinical presentation of gonnococcal cervicitis

1. Chorioamionitis
2. Premature rupture of membranes
3. Preterm birth, low birth weight, small for gestational age infants
4. Spontaneous abortion

What can gonnococcal cervicitis cause?

1. Neonatal conjunctivitis
2. Pharyngitis
3. Gonococcemia
4. Arthritis

What diseases can a mother with gonnococcal cervicitis pass on to her child during birth?

1. Triad= rash, arthralgia, tenosynovitis
2. Purulent arthritis
-monoarticular, larger joints, less common form

Clinical presentation of disseminated gonococcal

1. Profuse, purulent discharge
2. Conjunctival infection
3. Rapid progression to panophthalmitis and loss of eye
* may be transmitted to infant during vaginal delivery

Clinical presentation of gonococcal conjunctivitis

1. Gold standard= culture (gives sensitivities)
2. Cervical or urethral smear looking for gram negative diploccoci
3. Nucleic amplification tests
4. Chlamydia, gonorrhea, HIV, and syphilis tests

Diagnostics for gonococcal infections

1. All sexual partners within the past 60 days must be treated for gonnorrhea and chlamydia and tested for HIV and syphilis
2. Ceftriaxone 250mg IM + azithromycin 1g PO x 1 OR doxycycline 100mg PO bid x7 days
3. If disseminated gonococcal infection= Ceftr

Treatment for gonococcal infections

Moraxella catarrhalis
Most commonly seen in children with significance decreasing with age

What causes Moraxella catarrhalis

Respiratory droplets and fomites

How is Moraxella catarrhalis spread?

1. Otitis media (one of the top three causes of it in children)
2. Acute exacerbation of COPD
3. Acute bacterial rhinosinusitis

Clinical presentation of Moraxella catarrhalis

Typically only culture if non-responsive to first line treatments

Diagnostics of Moraxella catarrhalis

1. Depends on site of infection
2. Typically treated empirically
3. Almost all strains produce beta lactamase and are thus resistant to penicillin, ampicillin, amoxicillin, clindamycin, and vancomycin
-use a macrolide instead (clarithromycin)

Treatment of Moraxella catarrhalis

non-contagious- typically transmitted to humans via inhalation of aerosols derived from water or soil

How is Legionella bacterium spread?

Bacterial, atypical pneumonia caused by Legionella species- most commonly Legionella pneumophilia

What causes Legionnaire's disease?

1. High fever
2. Low pulse (bradycardia)
3. N, V, D

Clinical presentation of Legionnaire's disease

1. Hyponatremia
2. Elevated hepatic transaminases
3. C reactive protein levels >100mg/L
4. Failure to respond to treatment for pneumonia with beta lactam monotherapy

Diagnostic results of Legionnaire's disease

1. Macrolides
2. Quinolones
3. Tetracyclines
*no vaccine for prevention

Treatment of Legionnaire's disease

Legionella species

What causes Pontiac fever?

1. Headache
2. Fever
3. Muscle aches
4. Fatigue
*easily mistaken with the flu

Clinical presentation of Pontiac fever

Usually an acute self limited febrile illness (3-5 days)

Why are diagnostic tests and treatments not needed for Pontiac fever?

Pseudomonas aeruginosa
Opportunistic pathogen

What causes Pseudomonas skin disease (aka. Hot tub folliculitis), ecthyma gangrenosum, burn and wound infections, and nail infections?

Contact with infected water (most commonly from hot tubs)

How is Pseudomonas skin disease spread?

1. Malaise
2. Low grade fever
3. Erythematous pustules in occluded areas

Clinical presentation of Pseudomonas skin disease

1. Usually self limited
2. Fluoroquinolones for persistent disease or if very bothersome to patient

Treatment of Pseudomonas skin disease

Ulcerative lesion that extends through the epidermis and deep into the dermis
-appears as a punched out ulcer covered in crust surround by a raised violaceous margin

Clinical presentation of ecthyma gangrenosum

perivascular bacterial invasion of the media and adventitia of arteries and veins with secondary ischemic necrosis

What causes ecthyma gangrenosum?

1. Discoloration of scar
2. Erythema of tissue
3. May have a blue/green tinted drainage often with a sweet smell

Clinical presentation of burn and wound infections

Require surgical debridgement + multi drug treatment

Treatment of burn and wound infections

Green discoloration of finger or toe nail

Clinical presentation of nail infections

1. Confirm with culture before possible removal of nail
2. Bacitracin ointment 2-4 times a day for 1-2 months

Diagnostics and treatment of nail infections

1. Bronchitis/pneumonia (patients with cystic fibrosis)
2. Bacteremia (from medical intervention)
3. Endocarditis (prosthetic valves)
4. Malignant OE
5. Meningitis and brain abscess
6. Keratitis or endophthalmitis of eye
7. Osteomyelitis
8. GI infections

Clinical presentation of pseudomonal diseases

1. Gram stain
2. Culture of blood, urine, and/or sputum

Diagnostics of pseudomonal diseases

1. Varies with type of infection
2. Beta lactam antibiotics with an aminoglycoside
3. 2 antipseudomonal drugs from two different classes
4. Fluoroquinolones

Treatment of pseudomonal diseases

Brucella species

What causes brucellosis?

Ingestion of contaminated meat or milk, direct inoculation, or inhalation while animal is giving birth

How is brucellosis spread?

Cattle and other animals (this is a zoonotic infection)

What are some reservoirs of brucellosis?

Category B bioterrorism weapon

What are brucellosis and tularemia classified as?

1. Has a broad clinical spectrum ranging from asymptomatic disease to severe and/or fatal illness
2. Fever, myalgia, fatigue, headache, night sweats with strong odor, and depression are common

Clinical presentation of brucellosis

1. Isolation of organism on culture of blood or bone marrow
2. Serological testing

Diagnostics of brucellosis

1. Doxycycline
2. Rifampin
3. Streptomycin or gentamicin
*difficult to treat so you actually need to prescribe all three

Treatment of brucellosis

Francisella tularensis

What causes tularemia (aka. Rabbit fever)?

Infection through tick bite, food or water contamination, handling infected animal tissue, and/ or inhalation of aerosols
*no human to human transmission

How is tularemia spread?

1. Rapid onset of fever, chills, myalgia, anorexia, and dry cough
2. May have abdominal pain and D

Clinical presentation of tularemia

1. Ulceroglandular tularemia- most common
2. Glandular tularemia
3. Oculoglandular tularemia
4. Oropharyngeal tularemia
5. Pneumonic tularemia
6. Typhoidal tularemia

Specific manifestations of tularemia

1. High index of clinical suspicion
2. Specimen sent to Biosafety level 3 lab
3. Polymerase chain reaction and immunofluorescence testing of tissue samples
*poor yield with culture

Diagnostics of tularemia

1. Streptomycin or gentamicin for 7-14 days
2. Prophylaxis/mild disease= 14 day course of doxycycline or ciproflaxacin

Treatment of tularemia

Yersinia pestis

What causes plague?

Rodents with a vector (usually a flea)
-zoonotic

How is plague spread?

1. sudden onset of fever and chills
2. weakness
3. headache
4. followed by intense pain and swelling of lymph nodes

Clinical presentation of bubonic plague

1. disseminated intravascular coagulation
2. possible organ failure
3. blackening of the finger tips

Clinical presentation of septicemic plague (Black Death)

1. sudden onset of dyspnea
2. high fever
3. pleuritic chest pain
4. cough
5. may be accompanied by a bloody sputum

Clinical presentation of pulmonic plague (red death)

Primary= inhalation of respiratory droplets
Secondary= homogenous spread

How does pulmonic plague spread?

1. Gram stain of material from buboes
2. PCR on tissues
3. Serology- will see a rise in antibody titer to Y. Pestis
4. Cultures are slow growing so notify lab of suspicion

Diagnostics of plague

1. Immediate treatment for 10 days
-gentamycin loading dose then every 8hrs IV or streptomycin 1g every 12hrs IV
-if unable to tolerate, use doxycycline or tetracyclines
2. Prophylaxis= doxycycline 100mg bid for 7 days
* keep isolated until sputum is clea

Treatment of plague

Recketsia Rickettsii

What causes Rocky Mountain Spotted Fever?

Tick bite (American dog tick)

How is Rocky Mountain Spotted Fever spread?

1. Fever, malaise, headache, and arthralgia very common
2. Rash occurs in 90% of patients between days 3-5
-blanching erythematous rash with macules 1-4mm in size that become petechial
3. May present with abdominal pain, bleeding, and edema with CNS findi

Clinical presentation of Rocky Mountain Spotted Fever

1. Serological testing
2. Use of special stains on a skin biopsy preferably before antibiotics are started
*can not be cultured in most clinical labs

Diagnostics of Rocky Mountain Spotted Fever

Doxycycline 100mg daily IV or PO continued for 3 days after patient is afebrile

Treatment of Rocky Mountain Spotted Fever

Campylobacter jejuni or Campylobacter coli

What causes Campylobacter jejuni infection?

Largely food borne
-live in intestines of animals (especially chickens)

How is Campylobacter jejuni infection spread?

Late onset reactive arthritis or Guillain-Barr� syndrome

Clinical presentation of Campylobacter jejuni infection

1. Usually self limited with no need of antibiotics
2. Severe cases= azithromycin or Fluoroquinolones

Treatment of Campylobacter jejuni infection

1. Wash hands after handing raw chicken
2. Clean surfaces
3. Cook thoroughly

Campylobacter jejuni infection prevention

Salmonella

What causes Salmonellosis?

1. Typhoid
2. Nontyphoid

Types of Salmonellosis

Ingestion of poultry, eggs, milk, meats, and other food stuff or contact with pets (especially reptiles)

How is nontyphoid Salmonellosis spread?

Enteric fever

Clinical presentation of typhoid Salmonellosis

1. Generally self limited
2. Severe cases= ceftriaxone or Fluoroquinolones

Treatment of Salmonellosis

Shigella

What causes shigellosis?

1. High fever
2. Abdominal cramps
3. Frequent small bloody bowel movements

Clinical presentation of shigellosis

Typically self limited

Treatment of shigellosis

If severe, should do susceptibility testing as increase in resistant strains

Diagnostics of shigellosis

Vibrio cholerae

What causes cholera?

Contaminated water or food (most commonly rice and vegetables)

How is cholera spread?

1. Severe watery diarrhea that is white and fishy smelling
2. Severe fluid loss
3. Electrolyte imbalances

Clinical presentation of cholera

1. Aggressive fluid resuscitation (IV or PO)
2. Antibiotics for severe cases= tetracyclines, macrolides, Fluoroquinolones based on resistance patterns

Treatment of cholera

1. Clean water consumption
2. Vaccine

cholera prevention

Gonorrhea

What is the most common cause of urethritis in men under 30?

Gonorrhea

What is the second most common cause of reported communicable disease?

Chlamydia

What is the most common bacterial cause of STI?

Uterine cervix

What is the most common site of mucosal infection with Neissaria gonorrheae?