Hydrogen sulfide-negative variant of Citrobacter

Area of Science:

• Microbiology
• Clinical Microbiology
• Bacterial Pathogenesis

Background:

• Citrobacter species are Gram-negative bacteria.
• Some Citrobacter strains can be opportunistic pathogens.
• Hydrogen sulfide production is a biochemical characteristic used in bacterial identification.

Purpose of the Study:

• To characterize hydrogen sulfide-negative Citrobacter isolates.
• To determine the clinical significance of these isolates.
• To evaluate the antimicrobial susceptibility patterns of these strains.

Main Methods:

• Isolation and identification of bacterial strains.
• Biochemical testing (hydrogen sulfide production).
• Antimicrobial susceptibility testing using standard antibiotic panels.

Main Results:

• Twenty-five hydrogen sulfide-negative Citrobacter strains were identified.
• Most isolates originated from respiratory tract specimens.
• The clinical significance of these isolates was generally indeterminate.
• All strains exhibited high susceptibility to polymyxin B, gentamicin, kanamycin, nalidixic acid, and nitrofurantoin.

Conclusions:

• Hydrogen sulfide-negative Citrobacter strains are found in clinical settings, primarily the respiratory tract.
• These strains typically have indeterminate clinical significance.
• The isolates are highly susceptible to a range of clinically relevant antibiotics, suggesting effective treatment options are available.