Hiresave Srinivasa

Diabetes mellitus and HIV as co-morbidities in tuberculosis patients of rural south India.

OBJECTIVES Incidence of tuberculosis (TB) is greatest among patients with impaired immunity. India is experiencing a double epidemic of HIV and diabetes mellitus (DM), both of which are strongly associated with immuno-suppression. This study aimed to discover the prevalence of HIV and DM in both the pulmonary and extra-pulmonary TB patients of rural south India, retrospectively. METHODS Medical records of 192 microbiologically diagnosed pulmonary TB and 37 extra-pulmonary TB patients were thoroughly studied and data were extracted. The frequency distribution of HIV and DM was evaluated along with other demographic details such as age, sex and occupation in both groups. RESULTS The mean age of the pulmonary TB patients was 41.11±15.7 years, with significantly higher (p<0.0001) preponderance of DM (31.8%) over HIV (8.9%). 72.13% of the diabetic patients belonged to the age group of 41-60 years. Extra-pulmonary TB patients had a mean age of 34.62±12.9, years with a significantly higher (p<0.006) HIV prevalence of 32.43% over DM (5.4%). 75% of the HIV patients belonged to the age group of 41-60 years. Occupationally, the majority of the pulmonary TB patients were agricultural labourers (25.2%) while the majority of the extra-pulmonary TB patients were housewives or self employed (18.92%). CONCLUSION Though more importance is being given to HIV-TB coinfection, we cannot overlook DM, which showed a significantly higher prevalence in pulmonary TB patients compared to HIV. The rising prevalence of DM in high TB burden countries may adversely affect TB control.

Magnitude of drug resistant shigellosis: A report from Bangalore

Shigella is an important cause of acute invasive diarrhea in children and others. Antimicrobial susceptibility of Shigella spp. isolated from diarrhoeal/ dysenteric patients in Bangalore was studied in our hospital from January 2002 to December 2007. One hundred and thirty-four isolates were identified as Shigella species. S. flexneri, S. sonnei , S. boydii and S. dysenteriae were accounted respectively for 64.9%, 21.6%, 8.2% and 3.7% of the total number of Shigella isolated. Of these 56 (41.8%) were from children (0 to 14 years) and 78 (58.2%) were from adults and elderly patients. Over 70% of Shigella isolates were resistant to two or more drugs including Ampicillin and Co-trimoxazole. During 2002 to 2007, resistance to Ampicillin had increased from 46.7% to 68%. For Co-trimoxazole, though the resistance had gradually decreased from 100% to 72%, but still the resistance is high. Chloramphenicol resistance showed sudden decline from 73.3% to 25% from 2002 to 2003, but gradually has reached 48%. Nalidixic acid resistance was more than 70%. All isolates were sensitive to Ciprofloxacin during the period 2002 to 2004, but over the years the resistance pattern gradually increased up to 48%. Ceftriaxone had shown no resistance. The results of the study revealed the endemicity of Shigellosis with S. flexneri as the predominant serogroup. Children were at a higher risk of severe shigellosis. The results also suggest that Ampicillin, Co-trimoxazole, Chloramphenicol, Nalidixic acid and Ciprofloxacin should not be used empirically as the first line drugs in the treatment of Shigellosis. Periodic analysis and reporting of antibiotic susceptibility is an important measure to guide antibiotic treatment.

Isolation of bacteriophages to multi-drug resistant Enterococci obtained from diabetic foot: A novel antimicrobial agent waiting in the shelf?

INTRODUCTION While foot infections in persons with diabetes are initially treated empirically, therapy directed at known causative organisms may improve the outcome. Many studies have reported on the bacteriology of diabetic foot infections (DFIs), but the results have varied and have often been contradictory. The purpose of the research work is to call attention to a frightening twist in the antibiotic-resistant Enterococci problem in diabetic foot that has not received adequate attention from the medical fraternity and also the pharmaceutical pipeline for new antibiotics is drying up. MATERIALS AND METHODS Adult diabetic patients admitted for lower extremity infections from July 2008 to December 2009 in the medical wards and intensive care unit of medical teaching hospitals were included in the study. The extent of the lower extremity infection on admission was assessed based on Wagners classification from grades I to V. Specimens were collected from the lesions upon admission prior to the initiation of antibiotic therapy or within the first 48 h of admission. RESULTS During the 18-month prospective study, 32 strains of Enterococcus spp. (26 Enterococcus faecalis and 06 E. faecium) were recovered. Antibiotic sensitivity testing was done by Kirby-Bauers disk diffusion method. Isolates were screened for high-level aminoglycoside resistance (HLAR). A total of 65.6% of Enterococcus species showed HLAR. Multidrug resistance and concomitant resistance of HLAR strains to other antibiotics were quite high. None of the Enterococcus species was resistant to vancomycin. CONCLUSION Multidrug-resistant Enterococci are a real problem and continuous surveillance is necessary. Today, resistance has rendered most of the original antibiotics obsolete for many infections, mandating the development of alternative anti-infection modalities. One of such alternatives stemming up from an old idea is the bacteriophage therapy. In the present study, we could able to demonstrate the viable phages against MDR E. faecalis.

High concordance of genotypic coreceptor prediction in plasma-viral RNA and proviral DNA of HIV-1 subtype C: implications for use of whole blood DNA in resource-limited settings

OBJECTIVES Genotypic tropism testing (GTT) of HIV is increasingly used prior to the initiation of CCR5 antagonist therapy in HIV-infected individuals. Normally performed on plasma-derived virus, the test is challenging when performed in patients with suppressed viraemia. We aimed to evaluate the performance of cell-associated proviral DNA against plasma-derived viral RNA as the genetic material for GTT in an Indian clinical setting. METHODS From 52 HIV-1-infected individuals, the env V3 region was successfully amplified and sequenced from both proviral DNA and plasma RNA paired samples having a viral load >2500 copies/mL (n = 42) and from proviral DNA only in 10 antiretroviral therapy (ART)-experienced patients with a viral load <500 copies/mL. GTT was performed using the Geno2Pheno algorithm with the interpretative false positive rate (FPR) cut-off of 10%. RESULTS Among paired samples, 40 of 42 patients harboured subtype C strains. Plasma RNA tropism prediction revealed X4 tropism in 4 of 42 (9.5%). A high concordance of 97.6% in tropism prediction was noted in simultaneous RNA/DNA samples (38 R5 and 3 X4). Discordance was observed in one sample showing R5 tropism in proviral DNA and X4 tropism in plasma RNA. Comparison of Geno2Pheno FPRs in both the plasma and proviral compartments showed good correlation (overall, r = 0.87; ART-naive patients, r = 0.79; ART-failing patients, r = 0.97). GTT was successfully performed in all 10 whole blood DNA samples having a viral load <500 copies/mL, all showing R5 tropism. CONCLUSIONS High concordance in tropism prediction from proviral DNA and plasma-viral RNA suggests that prediction of viral tropism using proviral DNA is accurate and feasible in resource-limited clinical settings, particularly in patients with low or suppressed viraemia.

Ceftriaxone resistant Shigella Flexneri, an emerging problem

Shigellosis is a disease of public health importance in developing countries. It may cause self-limited diarrhea to severe dysentery. Emergence of multi drug resistant (MDR) strains is a growing concern globally. Ceftriaxone and ciprofloxacin are the drugs of choice for MDR cases. Here, we report a case of MDR Shigella flexneri from an immunocompromised patient. The strain was resistant to ceftriaxone [minimum inhibitory concentration (MIC) ≥ 64 μg/ml], limiting the treatment option. Simultaneously, the strain was also found to be resistant to ciprofloxacin (MIC ≥ 4 μg/ml). However, it was susceptible to ceftazidime (MIC 4 μg/ml). This is the first case of ceftriaxone resistant Shigella spp. reported from our hospital.

Performance of Genotypic Tools for Prediction of Tropism in HIV-1 Subtype C V3 Loop Sequences

Currently, there is no consensus on the genotypic tools to be used for tropism analysis in HIV-1 subtype C strains. Thus, the aim of the study was to evaluate the performance of the different V3 loop-based genotypic algorithms available. We compiled a dataset of 645 HIV-1 subtype C V3 loop sequences of known coreceptor phenotypes (531 R5-tropic/non-syncytium-inducing and 114 X4-tropic/R5X4-tropic/syncytium-inducing sequences) from the Los Alamos database (http://www.hiv.lanl.gov/) and previously published literature. Coreceptor usage was predicted based on this dataset using different software-based machine-learning algorithms as well as simple classical rules. All the sophisticated machine-learning methods showed a good concordance of above 85%. Geno2Pheno (false-positive rate cutoff of 5-15%) and CoRSeqV3-C were found to have a high predicting capability in determining both HIV-1 subtype C X4-tropic and R5-tropic strains. The current sophisticated genotypic tropism tools based on V3 loop perform well for tropism prediction in HIV-1 subtype C strains and can be used in clinical settings.

HIV-1 coreceptor tropism in India: increasing proportion of X4-tropism in subtype C strains over two decades.

Background:Recent studies show an increase in the frequency of X4-tropism in African HIV-1 subtype C (HIV-1C) strains and among Indian children with a longer duration of infection. There is limited availability of comprehensive data on HIV-1 tropism in Indian HIV-1C strains and impact on coreceptor antagonist drug susceptibility. We evaluated coreceptor tropism trends over 2 decades and maraviroc resistance-associated V3 loop substitutions among the Indian HIV-1C strains. Methods:We performed genotypic tropism testing using Geno2Pheno10% on primary samples from patients (n = 224) and on Indian HIV-1C sequences downloaded from the Los Alamos database (n = 528, 1991–2010). We also studied maraviroc resistance–associated substitutions in R5-tropic HIV-1C (n = 992) and subtype B sequences (n = 576). Results:Among primary samples, 88% belonged to HIV-1C and 11.2% was predicted as X4-tropic, with higher prevalence noted among patients from north-eastern India (19.1%) and significant association with intravenous drug users (P = 0.04). X4-tropism prevalence was higher among antiretroviral therapy–experienced (18.8%) compared with antiretroviral therapy–naive patients (9.1%). Indian database HIV-1C sequences showed X4-tropism at 4%. An increase in the X4 tropism frequency was seen over the years 1991 (1.6%) through 2012 (10%). We found a high frequency of 19T substitution (826/992; 83.3%) among HIV-1C V3 loop compared with subtype B. Conclusions:The predominance of R5-tropism in Indian HIV-1C strains despite a marginal temporal increase in X4-tropism prevalence highlights the likely effectiveness of coreceptor antagonists in India. Our frequent observation of common maraviroc resistance–associated substitutions among Indian R5-tropic HIV-1C raises the possibility that they may be natural polymorphisms, indicating the need for further elucidation.

The detection of ESBL-producing Escherichia coli in patients with symptomatic urinary tract infections using different diffusion methods in a rural setting

OBJECTIVES This study aimed to determine the prevalence of extended spectrum of beta lactamases (ESBLs), to compare different phenotypic methods for ESBL confirmation and to evaluate the antibiotic resistance patterns among ESBL-producing urinary Escherichia coli. METHODS Urinary E. coli isolates that were resistant to at least one of the three indicator cephalosporins (cefotaxime, cefpodoxime and ceftazidime) were tested for ESBL production using the double disc synergy test (DDST), the inhibitory potentiated disc diffusion (IPDD) test and the quantitative E-strip method. RESULT Of the 163 E. coli strains isolated, 80 (49%) were resistant to at least one of the three cephalosporins, and 38 (47.5%) tested positive for ESBLs by the IPDD test and the E-strip test. However, only15 (18.7%) strains tested positive by the DDST. Among the third-generation cephalosporins, cefpodoxime (46.1%) was the best screening indicator, followed by ceftazidime (43%) and cefotaxime (39.9%). Most of the ESBL producers (97.3%) were resistant to three or more drugs, compared with 51.2% of non-ESBL producers. CONCLUSION Compared with the DDST, the IPDD and E-strip tests appear to be preferable methods for detecting ESBLs, with better sensitivity (100%) and specificilty (97.6%) and positive predictive values (97.3%). ESBL producers showed significantly (p<0.05) higher resistance to tobramycin, co-amoxyclav and amikacin than did non-ESBL producers.

Multi-drug-resistant tuberculosis: the experience of an urban tertiary care hospital in South India using automated BACTEC 460 TB.

The emergence of multi-drug-resistant (MDR) strains has been a major obstacle in the tuberculosis (TB) control programme. In the present study we looked into the prevalence of MDR-TB in an urban tertiary care hospital in South India over four years (2007–2010). During this period, 641 clinical specimens (317 respiratory specimens and 324 non-respiratory specimens) were received for mycobacteriological culture and drug susceptibility testing for first-line drugs, using the BACTEC 460 TB system. Mycobacterium tuberculosis (MTB) was isolated in 34.8% (n = 223) specimens. Of the total 223 MTB isolates 83 (37.2%) were MDR. Forty-two percent of the pulmonary MTB isolates (n = 72) and 20.4% of the extra-pulmonary isolates (n = 10) were MDR. Although we observed a high percentage of drug resistance, the prevalence of MDR was not observed to vary significantly within the four years which suggested good management.

Epidemiology of culture isolates from peritoneal dialysis peritonitis patients in southern India using an automated blood culture system to culture peritoneal dialysate.

Aim:  Continuous ambulatory peritoneal dialysis (CAPD) is a major form of therapy for chronic end stage renal disease patients, which may lead to CAPD‐associated peritonitis. The spectrum of organisms associated with CAPD peritonitis varies geographically. Not much data is available regarding this from southern India. The aim of this study was to characterize the spectrum of organisms associated with CAPD peritonitis in this region and observe the utility of automated blood culture systems to culture peritoneal dialysate.