Viridans and bovis group streptococci that cause infective endocarditis in two regions with contrasting epidemiology.

Viridans group (VGS) or bovis group streptococci (BGS) are the major causes for streptococcal infective endocarditis (IE). However, the causative isolates are not sufficiently characterized. Using multilocus sequence analysis we have examined VGS and BGS (VGS/BGS) isolates that caused IE in southern India and Germany, two distant geographic regions with a contrasting IE epidemiology. Other than in Germany, the majority of patients (68%) in Chennai, southern India had an underlying rheumatic heart disease (RHD). In accord with the high prevalence of RHD in the younger population and with the expansive age structure of India, the median age (24 years) of the VGS/BGS endocarditis patients was lower than in Germany (63 years), where RHD is rare and the age structure is contractive. Both in Germany and in southern India, the majority of cases were caused by mitis group streptococci, however, with considerable differences in the spectra of causative (sub)species. BGS endocarditis was more frequent in Germany. The spectrum of VGS/BGS that cause IE differs considerably between distant geographic regions in which different predisposing conditions prevail. Therefore, improved microbiological diagnosis in IE may facilitate determination of the optimal therapy.

Chromogenic medium versus PCR-RFLP in the speciation of Candida: a comparative study.

OBJECTIVE: Candida species is implicated in a wide array of clinical infections. Speciation of Candida strains is of prime importance in the epidemiological survey and laboratory diagnosis as there is an upswing of antifungal resistance and changing trends in the antifungal resistance pattern among C. albicans and non albicans Candida. Varied phenotypic methods are available for the identification of Candida species which vary in principles and cost factors. Chromogenic agar medium (HiCrome Candida differential agar) is one of the preferred phenotypic methods in limited resource laboratories. Hence, this study was aimed to assess the reliability of HiCrome Candida differential agar, M1297A (HiMedia) in the identification of Candida species compared polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Oral Candida isolates (n = 194) were inoculated onto HiCrome Candida differential agar and the potential of Candida differential Agar was compared with PCR-RFLP. RESULTS: The results were not in agreement with PCR-RFLP. Percentage of disagreement was 40.2, 50.0, 100.0 and 25.0 for Candida albicans, Candida krusei, Candida glabrata and Candida tropicalis respectively. PCR-RFLP demonstrated a very high discriminatory power in the identification of Candida species compared to agar.

Mutant Prevention Concentration of Ciprofloxacin against Klebsiella pneumoniae Clinical Isolates: An Ideal Prognosticator in Treating Multidrug-Resistant Strains.

BACKGROUND: Fluoroquinolone-resistant Klebsiella pneumoniae poses a therapeutic challenge when implicated in urinary tract infections, pyelonephritis, pneumonia, skin infections, osteomyelitis, and respiratory infections. The mutant prevention concentration (MPC) represents a concentration threshold above which increase of resistant mutants occurs rarely. The aim of the present study is to determine the MPC among ciprofloxacin-resistant K. pneumoniae clinical isolates. MATERIALS AND METHODS: A total of 240 clinical isolates of K. pneumoniae were collected from a tertiary care hospital. The MPCs were determined for 24 selected strains using an inoculum of 1010 CFU/ml in Müller-Hinton agar plates with serial/various concentrations (0.003-100 µg) of ciprofloxacin. In addition to the MPC, phenotypic screening for ESBL, AmpC, and carbapenemase was performed. The detection of qnr genes for 24 isolates and DNA sequencing for six isolates were performed. RESULTS: Ciprofloxacin resistance was observed in 19.6% of the K. pneumoniae clinical isolates. Among the ciprofloxacin-resistant isolates, 14 isolates showed an MPC value of more than 100 µg. The MPC ranged between 100 µg and 20 µg for ciprofloxacin-resistant isolates. ESBL producers and qnr gene-producing strains had a high MPC. 11 isolates showed the presence of either qnrB or qnrS genes. None of the samples showed the presence of the qnrA gene. CONCLUSION: From our study, we infer that ESBL producers and qnr gene-possessing strains are frequently resistant to ciprofloxacin. Estimation of the MPC in the case of multidrug-resistant isolates in the clinical setup may help in treating these drug-resistant strains.