Flavobacterium indologenes

Flavobacterium indologenes is a species of Gram-negative bacteria belonging to the genus Flavobacterium. It is known for its distinctive yellow pigmentation and its ability to produce indole, a compound that is often used as a diagnostic marker in microbiology.

Morphology and Physiology

Flavobacterium indologenes is a rod-shaped, non-motile bacterium. It is characterized by its yellow pigmentation, which is due to the production of flexirubin-type pigments. The cells are typically 0.5-0.7 µm in width and 2-3 µm in length. This bacterium is aerobic, meaning it requires oxygen for growth, and it is capable of growing at temperatures ranging from 10°C to 37°C.

Biochemical Characteristics

Flavobacterium indologenes is oxidase positive and catalase positive. It is capable of producing indole from tryptophan, which is a key biochemical feature used to differentiate it from other species in the genus Flavobacterium. The bacterium can also hydrolyze gelatin and esculin, but it does not ferment glucose.

Habitat and Ecology

Flavobacterium indologenes is commonly found in soil and water environments. It has been isolated from various natural sources, including freshwater and marine ecosystems. The bacterium is also known to colonize hospital environments, where it can be found on medical equipment and surfaces.

Pathogenicity

Although Flavobacterium indologenes is not typically considered a major human pathogen, it has been associated with opportunistic infections, particularly in immunocompromised individuals. Infections can include bacteremia, pneumonia, and wound infections. The bacterium's ability to form biofilms on medical devices can contribute to its pathogenic potential in hospital settings.

Antibiotic Resistance

Flavobacterium indologenes exhibits resistance to multiple antibiotics, including beta-lactams and aminoglycosides. It is generally susceptible to quinolones and trimethoprim-sulfamethoxazole. The presence of intrinsic resistance mechanisms, such as efflux pumps and beta-lactamase production, complicates treatment options for infections caused by this bacterium.

Clinical Significance

In clinical settings, Flavobacterium indologenes is often isolated from respiratory secretions, blood, and wound cultures. Its identification in clinical specimens should prompt consideration of its potential role in infection, especially in patients with underlying health conditions or those who are immunocompromised.

Laboratory Identification

The identification of Flavobacterium indologenes in the laboratory involves a combination of phenotypic and genotypic methods. Phenotypic identification includes observing the characteristic yellow pigmentation, performing biochemical tests such as indole production, and assessing antibiotic susceptibility patterns. Molecular techniques, such as 16S rRNA gene sequencing, can provide definitive identification.

Prevention and Control

Preventing infections caused by Flavobacterium indologenes involves strict adherence to infection control practices in healthcare settings. This includes proper sterilization of medical equipment, hand hygiene, and environmental cleaning. Monitoring and surveillance of hospital-acquired infections can help in early detection and management of outbreaks.

Research and Future Directions

Ongoing research on Flavobacterium indologenes focuses on understanding its mechanisms of antibiotic resistance, biofilm formation, and pathogenicity. Advances in genomic and proteomic technologies are expected to provide deeper insights into the biology of this bacterium and its interactions with host organisms.