Multiple drug resistant carbapenemases producing Acinetobacter baumannii isolates harbours multiple R-plasmids.

BACKGROUND & OBJECTIVES: The nosocomial human pathogen Acinetobacter baumannii has high propensity to develop resistance to antimicrobials and to become multidrug resistant (MDR), consequently complicating the treatment. This study was carried out to investigate the presence of resistant plasmids (R-plasmids) among the clinical isolates of A. baumannii. In addition, the study was performed to check the presence of common ß-lactamases encoding genes on these plasmids. METHODS: A total of 55 clinical isolates of A. baumannii were included in the study and all were subjected to plasmid DNA isolation, followed by PCR to check the presence of resistance gene determinants such as blaOXA-23, blaOXA-51, blaOXA-58 and blaIMP-1 on these plasmids that encode for oxacillinase (OXA) and metallo-ß-lactamase (MBL) type of carbapenemases. Plasmid curing experiments were carried out on selected isolates using ethidium bromide and acridine orange as curing agents and the antibiotic resistance profiles were evaluated before and after curing. RESULTS: All the isolates were identified as A. baumannii by 16SrDNA amplification and sequencing. Plasmid DNA isolated from these isolates showed the occurrence of multiple plasmids with size ranging from 500bp to ≥25 kb. The percentage of blaOXA-51 and blaOXA-23 on plasmids were found to be 78 and 42 per cent, respectively and 20 isolates (36%) carried blaIMP-1 gene on plasmids. Significant difference was observed in the antibiograms of plasmid cured isolates when compared to their parental ones. The clinical isolates became susceptible to more than two antibiotic classes after curing of plasmids indicating plasmid borne resistance. INTERPRETATION & CONCLUSIONS: Our study determined the plasmid mediated resistance mechanisms and occurrence of different resistance genes on various plasmids isolated from MDR A. baumannii. The present findings showed the evidence for antibiotic resistance mediated through multiple plasmids in A. baumannii clinical isolates. This indicates towards a need for preventive measures to avert the dissemination of plasmid resistance determinants in clinical environments.

A rare case report of subcutaneous phaeohyphomycotic cyst caused by Exophiala oligosperma in an immunocompetent host with literature review.

We report a rare case of phaeohyphomycotic cyst in an immunocompetent patient caused by Exophiala oligosperma. This fungus is earlier known to cause infections in the immunocompromised. Identification of black fungi at species level is more challenging by conventional methods, and hence final identification of the fungi was based on sequencing of rDNA. The patient was managed with surgical excision. To the best of our knowledge, this is the first case report of E. oligosperma human infection from India.

Regional variations in antimicrobial susceptibility of community-acquired uropathogenic Escherichia coli in India: Findings of a multicentric study highlighting the importance of local antibiograms.

Objectives: Evidence-based prescribing is essential to optimize patient outcomes in cystitis. This requires knowledge of local antibiotic resistance rates. Diagnostic and Antimicrobial Stewardship (DASH) to Protect Antibiotics (https://dashuti.com/) is a multicentric mentorship program guiding centers in preparing, analyzing and disseminating local antibiograms to promote antimicrobial stewardship in community urinary tract infection. Here, we mapped the susceptibility profile of Escherichia coli from 22 Indian centers. Methods: These centers spanned 10 Indian states and three union territories. Antibiograms for urinary E. coli from the outpatient departments were collated. Standardization was achieved by regional online training; anomalies were resolved via consultation with study experts. Data were collated and analyzed. Results: Nationally, fosfomycin, with 94% susceptibility (inter-center range 83-97%), and nitrofurantoin, with 85% susceptibility (61-97%), retained the widest activity. The susceptibility rates were lower for co-trimoxazole (49%), fluoroquinolones (31%), and oral cephalosporins (26%). The rates for third- and fourth-generation cephalosporins were 46% and 52%, respectively, with 54% (33-58%) extended-spectrum ß-lactamase prevalence. Piperacillin-tazobactam (81%), amikacin (88%), and meropenem (88%) retained better activity; however, one center in Delhi recorded only 42% meropenem susceptibility. Susceptibility rates were mostly higher in South, West, and Northeast India; centers in the heavily populated Gangetic plains, across north and northwest India, had greater resistance. These findings highlight the importance of local antibiograms in guiding appropriate antimicrobial choices. Conclusions: Fosfomycin and nitrofurantoin are the preferred oral empirical choices for uncomplicated E. coli cystitis in India, although elevated resistance in some areas is concerning. Empiric use of fluoroquinolones and third-generation cephalosporins is discouraged, whereas piperacillin/tazobactam and aminoglycosides remain carbapenem-sparing parenteral agents.

Pneumococcal carriage at age 2 months is associated with growth deficits at age 6 months among infants in South India.

Nasopharyngeal colonization is the first step in the pathway to Streptococcus pneumoniae (Spn) infection, a leading cause of childhood morbidity and mortality. We investigated the effect of Spn colonization at ages 2 and 4 mo on growth at age 6 mo among 389 infants living in rural South India by using data from an Spn carriage study nested within a randomized, double-blind, placebo-controlled community trial designed to evaluate the impact of newborn vitamin A supplementation on Spn carriage in the first 6 mo of life. Primary outcomes were weight, length, and anthropometric indices of nutritional status. Growth data at age 6 mo were available for 84% (389 of 464) of infants in the Spn carriage study. Carriage at age 2 mo was associated with increased odds of stunting [OR: 3.07 (95% CI: 1.29, 7.36) P = 0.012] and lower weight [ß: -266 g (95% CI: -527, -5) P = 0.045], length [ß: -1.31 cm (95% CI: -2.32, -0.31) P = 0.010], and length-for-age Z scores [ß: -0.59; (95% CI: -1.05, -0.13) P = 0.012] at age 6 mo. Spn carriage at age 4 mo did not affect growth. Carriage of invasive serotypes at age 2 mo was associated with decreases in mean weight [ß: -289 g; (95% CI: -491, -106) P = 0.002] and length [ß:-0.38 cm (95% CI: -1.49, -0.01) P = 0.047] at age 6 mo. Newborn vitamin A supplementation did not modify the association between Spn carriage and growth. Results suggest that pneumococcal carriage at age 2 mo is an independent risk factor for poor growth in young infants. Future studies need to clarify the role of Spn carriage on growth retardation in low-income countries.

Immunoglobulin G Antibodies to SARS-CoV-2 Among Healthcare Workers at a Tertiary Care Center in South India.

Introduction Healthcare workers (HCWs) are at risk of exposure to SARS-CoV-2. Seroprevalence in this group may offer insights into trends to monitor and revise strategies to prevent transmission. Methods A cross-sectional study was conducted in two phases among healthcare workers at a tertiary care center to detect IgG antibodies to SARS-CoV-2. Seropositivity was calculated during both phases, and possible associations were determined using regression analysis. Results A total of 382 and 168 HCWs took part in the two phases, respectively. IgG antibodies were detected in 13 of 382 (3.4%; 95% confidence interval (CI): 2%-5.7%) and 71 of 168 (42.3%) participants in the first and second phases, respectively. Receiving at least one dose of vaccine (p < 0.001) and age (p = 0.028) were factors associated with the presence of antibodies, while gender, job type, exposure to COVID-19 cases, and comorbidities were not associated with seropositivity. Conclusion Serosurveys among HCWs may help identify transmission patterns and redesign infection control practices in the healthcare setting.

Coexistence of blaNDM-1, blaOXA-51, blaOXA-23, and armA in conjunction with novel mutations detected in RND efflux pump regulators in tigecycline resistant clinical isolates of Acinetobacter baumannii.

This study has investigated a total of 51 Acinetobacter baumannii isolates for the prevalence of resistant determinants in tigecycline susceptible and non-susceptible clinical isolates of A. baumannii. Antimicrobial susceptibility testing revealed 74% of isolates were tigecycline resistant. Mutations in RND-efflux pump regulatory genes and the expression of efflux pump genes were measured in tigecycline resistant isolates. There was a strong co-relation between the blaNDM-1 and armA wherein majority of the isolates that are positive for blaNDM-1 have also harbored armA. Compared with TSAB (tigecycline susceptible A. baumannii), TNAB (tigecycline non-susceptible A. baumannii) isolates show increased distribution of blaNDM-1 (P = 0.048), blaIMP-1 (P< 0.0001) and blaOXA-51 (P = 0.0029) carbapenemase genes. The variants of RND-efflux pump regulatory genes due to amino-acid mutations in adeS (F12S, K84E, W61R, N268H and Q299R) and adeL (G21R and Q262R) were identified in tigecycline resistant isolates as well as ISAba1 mediated disruption of adeN were observed causing overexpression of adeIJK efflux pump. Additionally, mutations in adeRS were also associated with increased expression of adeABC efflux pump. Besides, TNAB isolates showed significantly (P< 0.0001) higher ability of biofilm formation as compared to TSAB isolates. The tigecycline resistance due to mutations in contemporary A. baumannii isolates having a higher ability to form biofilm may pose therapeutic difficulties.

Detection of 16S rRNA gene for rapid identification of bacterial pathogens causing peritonitis in patients on continuous ambulatory peritoneal dialysis.

PURPOSE: Peritonitis is the most important complication with high rate of morbidity and mortality in patients on continuous ambulatory peritoneal dialysis (CAPD) despite the success and advances. Rapid and accurate identification of pathogens causing peritonitis in a CAPD patient is essential for early targeted treatment. The aim of the study was to evaluate the role of 16S rRNA gene and ITS region PCR and sequencing in detecting bacterial and fungal pathogens from the dialysate of patients undergoing CAPD. METHODS: Fifty eight peritoneal dialysate from suspected cases of peritonitis on CAPD were subjected to conventional culture as per the ISPD guidelines and automated culture system. A conventional PCR was performed to detect the 16S rRNA gene and ITS region. Sequencing and analysis were performed to identify the etiological agent from the remaining dialysate. RESULTS: Among the 58 dialysate fluid, the etiological agents were identified in 8(14%) samples by conventional culture, 28(48%) by automated culture and 47(81%) by 16S rRNA sequencing and analysis. In 8 samples there was discordance in the results of the culture and 16S rRNA PCR. BLAST search of nine sequences obtained from 16S rRNA PCR revealed that these sequences matched best with uncultured bacterial clones. In eleven samples the sequence failed. CONCLUSION: The molecular tool 16S rRNA gene and ITS region PCR and sequencing cannot be used as a standalone test as it lacks sensitivity to identify some bacterial species due to high genetic similarity in some cases and inadequate database in GenBank. However, it could be used as a supplementary test to the culture method especially in the diagnosis of culture negative peritonitis.

Safety and immunogenicity of a single dose, live-attenuated 'tetravalent dengue vaccine' in healthy Indian adults; a randomized, double-blind, placebo controlled phase I/II trial.

BACKGROUND: Dengue fever is the most prevalent mosquito-borne viral disease in the world, with 390 million dengue infections occurring every year. There is an unmet medical need to develop a safe, effective and affordable dengue vaccine against all four Dengue serotype viruses-DENV1, DENV-2, DENV-3 and DENV-4. Panacea Biotec Ltd (PBL) has developed a cell culture-derived, live-attenuated, lyophilized Tetravalent Dengue Vaccine (TDV). Here, in phase I/II study we assessed the safety and immunogenicity of single dose 'Dengue Tetravalent Vaccine' in healthy Indian adults. METHODS: In the study, 100 healthy adult volunteers aged 18-60 years were enrolled. The participants were allocated to TDV and placebo groups in 3:1 ratio, i.e. 75 participants to TDV group and 25 participants to the placebo group. Enrolled participants were administered a single dose of 0.5 ml of the test vaccine / placebo by subcutaneous route. Primary outcome for safety included all solicited AEs up to 21 days, unsolicited AEs up to 28 days and all AEs/serious adverse events (SAEs) till day 90 post-vaccination. For immunogenicity assessment the primary outcome was seroconversion & seropositivity rate by PRNT50 to all four serotype till 90 days. RESULTS: Overall, 100 subjects were vaccinated out of which 8 subjects (5 subjects in vaccine group and 3 subjects in placebo group) dropped out from the study. The most commonly reported solicited local AE was pain and most common solicited systemic AE was headache and fever. No SAE was reported during the study. There was no statistically significant difference between TDV and placebo groups in terms of AEs. Of the 92 subjects who completed all scheduled visits in the study, 59 (81.9%) achieved seroconversion for DENV-1, 56 (77.8%) for DENV-2; 59 (81.9%) for DENV-3 and 57 (79.2%) for DENV-4 in TDV group. The seroconversion rate in the TDV group was statistically significant (p < 0.001) compared to placebo.Clinical trial registration: CTRI/2017/02/007923.

Melioidosis: distinctive clinico-epidemiological characteristics in southern India.

As it is increasingly being reported from India, we carried out a prospective study of patients with culture-proven melioidosis from south India, examining clinical, laboratory features, epidemiological data, risk factors, treatments, outcomes at three and six months, and factors associated with mortality.Between 2014 and 2018, 31 cases were identified. Diabetes (83.9%) and alcohol abuse (58.1%) were common risk factors. Musculoskeletal, skin and soft tissue manifestations together constituted 48.4% of presentations, while 29% had pneumonia. During the intensive phase, 74.2% received one of three recommended antibiotic regimes, but 51.6% did not receive continuation treatment. Pneumonia and lack of continuation treatment were independently associated with a high mortality of 25.8%. Hot spots for melioidosis exist in India, and there is considerable diversity of presentation, including skin, soft tissue, musculoskeletal and neurological involvement. High rates of bacteraemia are shown.

Risk factors, bacteriological profile and outcome of surgical site infections following orthopaedic surgery.

BACKGROUND AND OBJECTIVES: Surgical site infection (SSI) is a challenge for the surgeon. Incidence of SSI reported in literature varies from 0.5% to 15%. Severity of SSI ranges from superficial skin infection to life-threatening condition like septicaemia. It is responsible for increased morbidity, mortality, and economic burden to the hospital in general, and the patient in particular. The aim of this study was to assess the risk factors, bacteriological profile, length of hospitalization, and cost due to orthopaedic SSI in patients admitted to a tertiary care hospital. MATERIALS AND METHODS: This was a prospective case control study. Cases were diagnosed based on CDC definition of nosocomial SSI. All cases were assessed preoperatively, intraoperatively and postoperatively, according to type of surgery, wound class, duration of operation, antimicrobial prophylaxis, use of drain, preoperative hospital stay, causative micro organism, total hospital stay, readmission rates and cost incurred. Age, sex and surgical procedure matched controls without SSI, were also assessed. Chi-square test and Fisher's exact test were used for analysis. P= <0.05 was considered significant. RESULTS: Out of 1023 patients, 47 cases had SSI, with a rate of 4.6%. Cigarette smoking was a risk factor for SSI (P = 0.0035). The most common etiologic agents were Acinetobacter baumannii and Staphylococcus aureus. Incidence of readmission among SSI cases was more compared to controls (P= 0.0001). Costs attributable to SSI (Indian Rupees) was Rs 32,542 (17,054 to 87,514) which was significantly more than those without SSI (P= <0.001). CONCLUSION: Despite latest surgical amenities, meticulous sterilization protocols and pre-operative antibiotic prophylaxis, SSI continues to be present in healthcare settings. The increase in duration of hospital stay due to SSI adds to additional burden to an already resource-constrained healthcare system.

Empiric antibiotic and in-vitro susceptibility of urosepsis pathogens: do they match? The outcome of a study from south India.

INTRODUCTION: Urosepsis is life threatening, unless treated immediately. Empirical treatment with appropriate antibiotics lowers the risk of a poor outcome. However, with increasing resistance among common uropathogens, there is a need for continuous review of the existing protocol to determine whether there is a correlation between empirical antibiotic therapy and in-vitro susceptibility pattern of the pathogens causing urosepsis. METHODOLOGY: A prospective study was carried out on 66 confirmed cases of urosepsis from January 2017 to December 2018 after obtaining ethical clearance. Demographic details, risk factors, length of hospital stay, bacteriological profile, empirical antibiotic given, and change in antibiotic following susceptibility report and outcome was recorded. RESULTS: Among the 66 urosepsis cases 63 of them were started on empiric antibiotic. The correlation between the empirical antibiotic given and the in-vitro antimicrobial susceptibility was found to be significant with a p value < 0.0001. Among the 63 for whom empiric antibiotics was started further escalation of antibiotic was done in 46 patients. The remaining 20% of cases were changed over to a different antibiotic, in line with susceptibility report. The mortality rate was (15.1%) with a confidence interval of (CI = 15 ± 3.5). The association between the risk factors for urosepsis and their effect on mortality rate was analyzed. Diabetes mellitus and chronic kidney disease were identified as important independent risk factors and had direct influence on the mortality rate with significant p value of 0.0281 and 0.0015 respectively. CONCLUSIONS: A significant correlation was identified between the empirical antibiotic given and in-vitro antibiotic susceptibility pattern.

Phenotypic and genotypic assays for detecting the prevalence of metallo-beta-lactamases in clinical isolates of Acinetobacter baumannii from a South Indian tertiary care hospital.

Nosocomial infections caused by Acinetobacter baumannii often prove difficult to treat owing to their multiple drug resistance. Carbapenems play a pivotal role in the management of severe Acinetobacter infections. However, reports of carbapenem resistance have been increasing alarmingly due to production of a variety of carbapenemases including metallo-beta-lactamases (MBLs). This study investigated by both phenotypic and genotypic assays the prevalence of MBLs in a total of 55 A. baumannii strains isolated from a South Indian tertiary care hospital. Random amplified polymorphic DNA (RAPD) genotyping and antimicrobial susceptibility testing for nine clinically relevant antibiotics was done for characterization of isolates. Phenotypic expression of MBLs was examined by a simple double disc synergy (DDS) test, and the presence of the most frequent MBL coding genes, bla(IMP1) and bla(VIM2), was checked by PCR. RAPD analysis generated six clusters of isolates and there was very little correlation between RAPD clusters and resistant profiles. Most of the isolates showed complete or high resistance to imipenem (100 %), meropenem (89 %), amikacin (80 %), cefotaxime (89 %) and ciprofloxacin (72 %). In addition, 44 % of isolates showed a high MIC level (> or =16 microg ml(-1)) for meropenem. Thirty-nine isolates (70.9 %) were positive for MBL production by the DDS test while bla(IMP1) gene amplification was seen only in 23 isolates (42 %). Interestingly, none of the isolates showed amplification of bla(VIM2). Further investigations on DDS-positive/PCR-negative isolates by spectrophotometric assay showed MBL activity in most of the isolates, suggesting involvement of other genes. The high incidence of isolates possessing MBL activity in the present study represents an emerging threat of complete resistance to carbapenems among Acinetobacter spp. in India.

Association of ABO blood groups with dengue fever and its complications in a tertiary care hospital.

CONTEXT: Dengue fever (DF) has been steadily increasing in India with outbreaks in certain areas taking the proportion of epidemics. Along with secondary dengue, several risk factors predispose to dengue hemorrhagic fever and dengue shock syndrome. Very few studies associating the relationship between dengue and its severity with ABO blood group have been documented. AIMS: The aim of this study was to determine the association between distribution of ABO Rh blood groups and DF and DF with thrombocytopenia. SETTINGS AND DESIGN: This was a retrospective descriptive study conducted at the clinical laboratory of the department of microbiology. MATERIALS AND METHODS: Dengue patients whose case record contained information on blood group were screened for details of blood group and confirmed dengue diagnosis. Randomly 384 case records were selected. These were divided into two groups; Group 1 included DF cases (platelet count >20,000) and Group 2 included DF cases with thrombocytopenia (platelet count <20,000). Control group consisted of patients other than dengue, whose blood grouping had been done; randomly 390 were selected and analyzed. STATISTICAL ANALYSIS USED: P value was calculated using the Chi-square test. Odds ratio were calculated using the Fisher's exact test. RESULTS: DF was higher in 23% of individuals with AB blood group as compared to 8.5% of controls (P = 0.0004), whereas patients with blood group O were significantly less affected with DF (P = 0.0048). Disease severity was not associated with any of the blood groups. CONCLUSIONS: Individuals with AB blood group are more prone to DF, whereas individuals with blood group O are less prone.

Evaluation of loop-mediated isothermal amplification assay for detection of scrub typhus in patients with acute febrile illness presenting to a Tertiary Care Center in Puducherry, India.

PURPOSE: Scrub typhus an acute febrile illness has diverse clinical manifestations, which overlap with other febrile illnesses. Due to this reason, it is misdiagnosed, leading to inappropriate treatment, sometimes resulting in fatality. Thus, accurate diagnosis of scrub typhus is important for appropriate treatment. This study evaluated the loop-mediated isothermal amplification (LAMP) assay as a diagnostic test for scrub typhus among patients with fever. MATERIALS AND METHODS: A total of 50 cases of acute febrile illness clinically resembling scrub typhus, with or without an eschar, or cases of pyrexia of unknown origin were included in the study. Blood samples collected from these cases were subjected to detection of IgM antibodies to Orientia tsutsugamushi by ELISA, conventional groEL polymerase chain reaction (PCR), and the LAMP assay. RESULTS: Twelve cases had fever for less than a week, and two had fever for more than 3 weeks. IgM antibodies to O. tsutsugamushi were detected in 37 out of 50 samples (74%). LAMP assay was positive in 33 samples (66%). groEL gene-based PCR detected 35 (70%) samples as positive. Two samples negative by LAMP assay were positive by this PCR. Twenty samples collected from patients with dengue, typhoid, and malaria tested by the LAMP assay were negative, indicating its good specificity. LAMP assay and the conventional groEL-based PCR could detect 72.7% and 74.3% of the samples, respectively before the 10th day after onset of fever, whereas IgM ELISA could detect only 40.5% of the 37 samples. CONCLUSION: This study suggests that LAMP assay could be a useful diagnostic test for detecting scrub typhus in the acute phase of the illness and a cheaper alternative to other molecular methods in resource poor settings.

Diagnostic utility of bone marrow examination in evaluation of fever: a descriptive study on 98 immunocompetent adults from a tertiary care institute in south India.

Five-year clinico-laboratory data from 99 (one HIV seropositive) adults (mean age = 41.3 ± 20.4 years) who underwent bone marrow examination for fever persisting for ≥ 1 week were analysed and correlated with microbiological characteristics. Infections, reactive marrow changes and haematolymphoid malignancies were most commonly associated with fever. A high concordance rate of 71% was noted between aspiration and trephine biopsies. Bone marrow granulomas (BMG) were seen exclusively on sections and were most commonly of tubercular and typhoidal in origin (two Salmonella Typhi, one Salmonella Paratyphi A). The common aetiologies associated with fever and cytopenia(s) were BMG, acute leukaemia and haemophagocytic lymphohistiocytosis (HLH; n = 3). The yield from bone marrow culture was inferior compared to other body fluids. In conclusion, bone marrow histology is superior to smears in the evaluation of prolonged fever. Marrow culture may not be useful in immunocompetent individuals other than if Salmonellosis is suspected.

Evaluation of LAMP-based assays for carbapenemase genes.

Purpose. Rapid and accurate detection of carbapenem resistance is a critical requirement for the selection of appropriate therapy and initiation of infection control measures. Although several tests are available, their use is limited by one or more factors. Phenotypic tests are lengthy, have variable sensitivity and specificity and do not generally identify the carbapenemase. Molecular assays overcome many of these issues but cost can be a barrier to adoption, particularly in low-resource settings. To address the need for affordable, molecular tools, we have assessed the performance characteristics of loop-mediated isothermal amplification (LAMP)-based assays for the major carbapenemase genes, blaNDM, blaKPC, blaOXA-48, blaOXA-23 blaVIM and blaIMP.Methodology. The assays were validated using 1849 Gram-negative Indian clinical isolates obtained from seven hospitals and diagnostic centres.Results. The assays had diagnostic sensitivities of 98.14 %, 98.92 %, 100 %, 98.48 %, and diagnostic specificities of 98.94 %, 99.61 %, 97.42 %, 99.38 % for blaNDM, blaOXA-48, blaOXA-23 and blaVIM, respectively. Due to a low number of isolates positive for blaKPC and blaIMP, the performance characteristics of assays for these two genes could not be suitably evaluated.Conclusion. The performance characteristics suggest suitability for diagnostic and surveillance purposes.

Multidrug-resistant Enterobacteriaceae colonising the gut of adult rural population in South India.

BACKGROUND: Multidrug-resistant (MDR) colonisers act as a reservoir for transmission of antibiotic resistance and are a source of infection. Exposure to antibiotics by the commensal flora renders them resistant. Antibiotic consumption and hospitalisation are two major factors influencing this. We studied, antibiotic-resistant bacteria colonising rural adult population who had restricted access to health care and presumably had low consumption of antibiotics. AIM: Detection of multidrug resistance genes of extended spectrum ß-lactamase (ESBL-CTX-M), AmpC ß-Lactamase (CIT), Klebsiella pneumoniae carbapenemase (KPC) and New Delhi Metallo ß-lactamase (NDM) in Enterobacteriaceae colonising the gut of adult population in a South Indian rural community. METHODOLOGY: Faecal samples of 154 healthy volunteers were screened for Enterobacteriaceae resistant to commonly used antibiotics by standard methods, followed by phenotypic detection of ESBL by double disk synergy method, AmpC by spot inoculation and carbapenemases by imipenem and ethylenediaminetetraacetic acid + imipenem combined E-test strips and modified Hodge test. Polymerase chain reaction was done to detect blaCTX-M,blaCIT,blaKPC-1 and blaNDM-1 genes coding for ESBL, AmpC, KPC and NDM, respectively. RESULTS: Colonisation rate of enteric bacteria with MDR genes in the community was 30.1%. However, phenotypically, only ESBL (3.2%) and NDM (0.65%) were detected. While the genes coding for ESBL, AmpC and NDM were detected in 35.6%, 17.8% and 4.4% of the MDR isolates, respectively. CONCLUSIONS: Carriage of MDR strains with a potential to express multidrug resistance poses a threat of dissemination in the community. Awareness for restricted use of antibiotics and proper sanitation can contain the spread of resistant bacteria.

Antimicrobial susceptibility patterns of Salmonella enterica serotype typhi in eastern Nepal.

The aim of the present study was to evaluate antimicrobial susceptibility patterns with special reference to multidrug resistance, susceptibility to ciprofloxacin, and bacteriophage typing of Salmonella enterica serotype Typhi isolated from blood sent for culture in a tertiary-care teaching hospital in eastern Nepal during January 2000-December 2004. In total, 132 strains of S. enterica Typhi, isolated from 2,568 blood culture samples collected from cases of suspected enteric fever, were tested for susceptibility to commonly-used antimicrobials by the disc-diffusion method. There were 35 multidrug-resistant strains. None of the isolates were resistant to ciprofloxacin. Of 52 isolates tested for minimum inhibitory concentration (MIC) of ciprofloxacin, 36 (69.23%) showed reduced susceptibility (MIC >0.25 mg/L). Of 112 strains tested for nalidixic acid susceptibility, 86 (76%) were resistant. Strains with reduced susceptibility to ciprofloxacin and resistance to nalidixic acid could be correlated. The commonest phage type was El. Nalidixic acid susceptibility could be a useful screening test for the detection of decreased susceptibility of S. Typhi to ciprofloxacin, a drug which is commonly used even for minor ailments in this area.