Infectious Diseases Plate Rounds 6-19-24.pptx

Infectious Diseases Plate Rounds 6-19-24.pptx

1. Plate Round Discussion 6/19/24 Case 1 : E. coli and Citrobacter farmeri in pericarditis Case 2: R elapse MAC, now resistant to amikacin Case 3: Peptoniphilus asaccharolyticus bacteremia

2. Escherichia Coli Widely distributed in nature, water, soil, foods, and clinical samples. Occupies the intestines in humans and warm-blooded animals. Good indicator if the water is clean (fecal contamination)

3. Diagnostic testing Gram Negative Bacilli Non-swarming, oxidase negative, Indole Positive, Lactose positive, catalase positive C olonies appear round, smooth, low convex, moist and gray with a shiny surface. Some strains may demonstrate β-hemolysis. Susceptibility- Ampicillin, Pip/ Tazo , Ciprofloxacin, Cephalosporins, Levofloxacin, SXT,

4. Citrobacter Farmeri Many Citrobacter infections are nosocomially acquired; however, they can also be community acquired. Citrobacter  species are commonly found in water and human feces, soil, food, and the intestinal tracts of animals. Slower lactose fermenter

5. Diagnostic Testing Citrobacter species are straight, facultative anaerobic, Gram-negative bacilli and are typically motile by means of flagella Part of the Enterobacteriaceae Family Indole=pos, ornithine=pos, ONPG=pos, Catalase=pos, H2S=neg Slower lactose fermenter Susceptibility- aminoglycosides, fluoroquinolones, carbapenems, and the fourth-generation cephems, such as cefepime and cefpirome, would appear to be preferred therapeutic 

6. Mycobacterium Avium Complex Mycobacterium avium complex (MAC)  is a group of bacteria related to tuberculosis. MAC includes two closely related species:  Mycobacterium avium  and  Mycobacterium intracellulare . These bacteria are commonly found in soil, water, and dust. usually causes infection in those who are immunocompromised or those with severe lung disease.

7. Diagnostic Testing Gram-Negative, non-motile, rod-shaped bacteria Morphology= Most are yellow pigment with spreading colonies with a characteristic fruity odor Grows on most media including MAC Oxidase neg, catalase neg, and urease neg Susceptibility= They often exhibit resistance to penicillin, cephalosporins, and carbapenems. variable susceptibility to aminoglycosides, quinolones, and SXT.

8. Peptoniphilus asaccharolyticus Peptoniphilus asaccharolyticus is present as part of the microbiota of the lower reproductive tract of women and has been recovered from women with pelvic inflammatory disease. Peptoniphilus are gram positive anaerobic cocci Peptoniphilus was formerly classified in the genus Peptostreptococcus.

9. Diagnostic testing gram positive anaerobic cocci Indole neg, urease neg, catalase pos, not many biochems reactions so molecular ID is best Formally in the peptostreptococcus family Susceptibility=penicillin, cephalosporins, clindamycin, carbapenems