Introduction of Morgenella
Morgenella morganii is a member of the family Enterobacteriaceae which was earlier called Proteus morganii. This genus Morgenella has only one species, M. morganii. It can be found in human and animal tissues and sewage, soil, and water.
Pathogenecity of Morgenella
It cause rarely urinary tract infections (UTI),hospital-acquired infections and it has also been reported as causing diarrhea in infants.
Laboratory Diagnosis of Morgenella
Gram stain: Gram-negative bacilli
Culture: Non-lactose fermenting colonies on MacConkey agar. Blood agar is lacking swarming type growth i.e. having individual colonies.
In triple sugar iron agar (TSI) test-
Red slant, yellow butt
No hydrogen sulfide (H2S) production
About gas formation- different strains give different results
Motility indole and urease (MIU) test –
Generally motile ( a few strains may be non-motile)
Indole test- positive
Urea hydrolyzation test-Positive
Citrate utilization test
Phenylalanine deaminase (PDA) also called phenyl pyruvic acid (PPA) test
Treatment of Morgenella
M. morganii strains are intrinsic resistant to penicillin, ampicillin, ampicillin, and combination of sulbactam, oxacillin, first-generation and second-generation cephalosporins, erythromycin, tigecycline, colistin, and polymyxin B and susceptible to piperacillin, ticarcillin, mezlocillin, third-generation, and fourth-generation cephalosporins, carbapenems, aztreonam, fluoroquinolones, aminoglycosides, and chloramphenicol. Even the widespread use of third-generation cephalosporins has been associated with the emergence of highly resistant M. morganii.
A 47 years old female patient having signs and symptoms of urinary tract infection (UTI) so the clinician requested a urine routine examination. The report was suggestive for UTI having plenty of pus cells and few red blood cells and thus clinician finally ordered urine culture and sensitivity.
Morgenella morganii isolated (>105CFU/ml)
The patient was treated with ofloxacin and finally, she was cured of UTI.
Supportive features of lab diagnosis as shown above figure.
- Topley and Wilson’s microbiology and microbial infection- Bacteriology-2-10th Edition
- Manual of Clinical Microbiology-Patrick R. Murray -8th Edition
- Bailey and Scott’s Diagnostic Microbiology-13th Edition
- Mackie & Mc Cartney Practical Medical Microbiology- 14th Edition
- Diagnostic Microbiology-Connie R. Mahon & George Manuselis
- District Laboratory Practice in Tropical Countries- Part-2- Monica Cheesebrogh- 2nd Edition Update