WKI Sales Training Feb 2014

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Unique Clinical Features

Summaries of bacteria and their diseases

Gram (+) cocci

• Catalase (+) • Nonmotile • Donot form spores • Round cocci tending tooccur inbunches likegrapes • Facultativeanaerobic organisms • Culturedon enrichedmedia containingbroth and/or blood

Colonies are yellow

Staphylococcus species

Summary of common diseases

Staphylococcus aureus

• Skin and soft

• Septicemia • Necrotizingpneumonia • Toxicshocksyndrome • Foodpoisoning (antibiotic therapy not used)

tissue infections

URINARY TRACT INFECTIONS

• Osteomyelitis • Septicarthritis • Endocarditis

Staphylococcus aureus on blood agar surrounded by zoneof β hemo- lysis.

A

Classification of pathogens B

Common causes of UTI 1

Staphylococcus aureus cultured fromawound infection

Methicillin susceptible

1 Oxacillin

1 Nafcillin

Escherichia coli

Staphylococcus epidermidis

Staphylococcus saprophyticus

Gram (+)cocci

• Infectionsof catheters andheartvalves

• Cystitis inwomen

Methicillin resistant (health-careassociated)

Staphylococcus saprophyticus

Staphylococcus saprophyticus

Ciprofloxacin

Gram (–) rods

1 Oxacillin

1 Vancomycin

Escherichia coli

Klebsiella

1 Nafcillin

Proteus Klebsiella

Methicillin resistant (community-acquired; mild-moderate infection)

Proteus

Pseudomonas aeruginosa

2 Vancomycin 2

Pseudomonasaeruginosa

1Most isolates resistant topenicillinG 2Used inmethicillin-resistant isolates

1 Trimthoprim/ sulfmethoxazole

0 10

60 70 80 90 50 40 30 20

1 Doxycycline

Approximateprevalence (%)

Common complaints

C

Pseudomonas aeruginosa • P.aeruginosa isa significantopportunistic pathogen,andamajor causeofhospital-acquired (nosocomial) infections suchasUTI,particularly inpatientswhohavebeen subjected to catheterization, instrumentation, surgery,or renal transplantationor topriorantibiotic therapy. • P.aeruginosadisease beginswith attachment and colonizationof host tissue.Pilion the bacteriamediate adherence, and glycocalyx capsule reduces the effectiveness of nor al clearancemechanisms.Host tissue damage facilitates adherence and colonization.Because pseudomonas infections typically occur in patientswith impaired defenses, aggressive antimicrobial therapy is generally required. Other enterobacteria • OthergeneraofEnterobacteriaceae, uch as Klebsiella,Enterobacter,Proteus, andSerratia, which canbe found as normal inhabitants of the large intestine, includeorganisms that are primarily opportunisticand often nosocomial pathogens.Theyall frequently colonize hospitalized patients,especially in association withantibiotic treatment, indwelling catheters, or invasiveprocedures, causing extra-intestinal infections such as those of the urinary tract. • These organisms produce exotoxins. Wide-spread antibiotic resistance among these organismsnecessitates sensitivity testing to determine theappropriate antibiotic treatment.

Methicillin resistant (community-acquired; severe infection)

Staphylococcus saprophyticus • S. saprophyticus isa frequent causeof cystitis inwomen,probably related to itsoccurrence as part ofnormal vaginal flora. It is alsoan importantagentof hospital-acquired infections associatedwith the use of catheters. • S. saprophyticus isa coagulase-negative staphylococcal species. It tends tobe sensitive tomostantibiotics,evenpenicillinG. It canbe distinguished frommostother coagulase-negative staphylococci by itsnatural resistance tonovobiocin. Escherichia coli • E. coli is themost common causeof urinary tract infections (UTI), including cystitisand pyelonephritis.Women are particularly at risk for infection.Transmission is frequently from the patient’s flora. • Uncomplicated cystitis (themost commonly encounteredUTI) is caused by uropathogenic strains ofE. coli, characterized byP fimbriae (an adherence factor).ComplicatedUTI (pyelonephritis)oftenoccurs in settingsof obstructed urinary flow,andmay be causedby nonuropathogenic strainsofE. coli.UTI require treatmentwith antibiotics.

2 Teicoplanin dalfopristin 2 1 Vancomycin 1 Linezolid 1 Daptomycin Quinupristin-

Carbuncle caused by Staphylococcus aureus

Furuncle caused by Staphylococcus aureus

Note:TreatmentofMRSAmayvaryby the typeand locationof infection.

DYSURIA LUMBARPAIN

108 104 100 98

Normal

94

FEVER

Staphylococcal scalded skin syndrome

Superficial impetigo

Folliculitis causedby Staphylococcus aureus

Figure 8.12 Summary of staphylococcal disease.

1 2 Indicates first-line drugs; indicates alternative drugs.

CHILLS

Figure 33.4 (continued on the next page)

Disease summary of urinary tract infections. 1 Uncomplicated cystitis.

Illustrated Case Studies

Case 1: Man with necrosis of the great toe

second postoperative day he became disoriented and his temperature reached 105.2 o F. His amputation stump was mottled with many areas of purplish discoloration, and the most distal areas were quite obviously necrotic (dead). Crepitus (the sensation of displacing gas when an area is pressed with the fingers) was palpable up to his patella. An X-ray of the left lower extremity showed gas in the soft tis- sues, extending beyond the knee to the area of the distal femur. A Gram stain of a swab from the necrotic tissue is shown in Figure 34.2.

This 63-year-old man with a long history of diabetes mellitus was seen in consultation because of an abrupt deterioration in his clinical status. He was admitted to the hospital for treatment of an ulcer, which had been present on his left great toe for several months. Figure 34.1 shows a typical example of perforating ulcer in a diabetic man. Because of the inability of medical therapy (multiple courses of oral antibiotics) to resolve the ulcer, he underwent ampu- tation of his left leg below the knee. On the first postopera- tive day he developed a temperature of 101 o F, and on the

Quick Review

Herpesviridae Epstein-Barr virus

Common characteristics • Linear, double-stranded DNA genome • Replicate in the nucleus

Polymorphonuclear leukocyte

Double stranded Enveloped

Grampositive bacillus Herpes simplex virus,Type 1 Herpes simplex virus,Type 2 Human cytomegalovirus Human herpesvirus,Type 8 Varicella-zoster virus

• Envelope contains antigenic, species-specific glycoproteins • In the tegument between the envelope and capsid are a number of virus-coded enzymes and transcription factors essential for initiation of the infectious cycle • All herpesviruses can enter a latent state following primary infection, to be reactivated at a later time

Figure 34.2 Gram stain of material swabbed from deep within a crepitant area. There are numerous polymorpho- nuclear leukocytes, and many large gram-positive bacilli, as well as a few gram-negative bacilli and cocci.

Figure 34.1 Perforating ulcer of the great toe.