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Purpose: Identifying asymptomatic SARS-COV-2 carriage is one of the crucial factors in controlling the COVID 19 pandemic. The relationship between the asymptomatic viral carriage and the rate of seroconversion needs better understanding. The present study was conducted to identify the asymptomatic COVID-19 infection and seropositivity in high-risk contacts in the southern district of Delhi, India. Methods: Following the screening of 6961 subjects, a total of 407 asymptomatic high-risk subjects were selected. Demographic data, socioeconomic status, and history of COVID-19 related symptoms in the last 4 months were recorded. Blood samples and Nasopharyngeal/oropharyngeal swabs were collected for the detection of SARSCOV-2 RNA and anti-SARS-COV-2 antibodies. Results: 55 asymptomatic high-risk subjects (13.5%) tested positive for SARS-COV-2 infection and among them, 70.9% remained asymptomatic throughout their course of infection. The seropositivity among the subjects was 28.9% (n ¼ 118) and was found significantly higher among lower-middle socioeconomic strata (p ¼ 0.01). The antibody levels were significantly higher (p ¼ 0.033) in individuals with a previous history of COVID-19 like symptoms as compared to the subjects, who had no such history. Asymptomatic healthcare workers showed a significantly increased rate of SARS-COV-2 infection (p ¼ 0.004) and seropositivity (p ¼ 0.005) as compared to the non-healthcare workers. Subjects, who were exposed to infection at their workplace (non-hospital setting) had the least RT-PCR positivity rate (p ¼ 0.03). Conclusions: A large proportion of SARS-COV-2 infection remains completely asymptomatic. The rate of asymptomatic carriage and seropositivity is significantly higher in healthcare workers as compared to the general population. The level of SARS-COV-2 antibodies is directly related to the appearance of symptoms. These observations may contribute to redefining COVID 19 screening, infection control, and professional health practice strategies.
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Background & objectives: Infections caused by vancomycin-resistant Enterococci are difficult to treat given the limited therapeutic alternatives. Different gene clusters are known to confer vancomycin resistance. vanA and vanB genes are transferable and are clinically relevant. This cross-sectional study aimed to identify the vancomycin-resistant genotypes in the strains causing urinary tract infection and also to test the in vitro efficacy of linezolid and pristinamycin against the vancomycin-resistant isolates. Methods: Antimicrobial resistance profile of 118 enterococcal isolates was evaluated. Minimum inhibitory concentration of vancomycin, teicoplanin and high-level gentamicin (HLG) was determined by micro broth dilution. The vancomycin-resistant isolates were tested against linezolid and pristinamycin by micro-broth dilution and E strip method. The presence of vancomycin-resistant genes was detected by multiplex polymerase chain reaction and was sequenced and analyzed. Results: Most commonly isolated species were Enterococcus faecalis (76.9%) and Enterococcus faecium (16.9%). It was found that 43 per cent of the isolates were resistant to HLG and 16.9 per cent to vancomycin. Higher resistance was seen against fluoroquinolones, erythromycin, tetracycline and ?-lactam drugs. However, 5.08 per cent strains were resistant to tigecycline. All vancomycin-resistant strains were sensitive to pristinamycin and one was resistant to linezolid. vanA and vanB gene were found in 15 and five isolates, respectively. The gene sequences were submitted to NCBI gene bank and accession numbers were obtained. Interpretation & conclusions: The present study showed prevalence of vanA and vanB genes carrying Enterococcus in a tertiary care centre in north India. The emergence of resistance against drugs such as tigecycline and linezolid is a topic of concern as it will be a therapeutic challenge for physicians.
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Background: Increasing Carbapenem resistance in Pseudomonas aeruginosa is an emerging threat and a matter of particular concern. Aim: Our study was conducted to find out the prevalence of Metallo beta lactamase producing Pseudomonas aeruginosa and compare various phenotypic MBL detection methods. Methods: A prospective study was conducted on 86 non duplicate Pseudomonas aeruginosa strains isolated from clinical specimens for a period of 2 year from April 2011 to march 2013. Total 86 isolates of Pseudomonas aeruginosa were included in the study. All clinical samples were processed according to standard microbiological method. The MIC for Imipenem and Meropenem were determined by broth dilution method. As per CLSI any isolate having an MIC of >8μg/ml was considered resistant.42 isolates were both or either resistant to IMP and MRP. These 42 isolates were tested for MBL production by (a) IMP EDTA E test (17 MBL positive isolate detected), (b) IMP & IMP EDTA disc diffusion test (17 MBL positive isolate detected), (c) IMP & EDTA double disc synergy test (14 MBL positive isolate detected). Results: 48.84% isolates were resistant to Carbapenem and 19.76% isolates were found to be MBL producer. Colistin showed 100% susceptibility in all the MBL positive isolates. Conclusions: Among the 3 test done IMP & IMP EDTA test is easy to perform, cost effective and as sensitive as E test. Our results strongly suggest that for the MBL isolates should be detected on routine basis and the antibiotic prescribed accordingly.
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Background: Enterococci causes serious infection due to its higher ability to colonize and increasing resistance to various drugs. Mutation and plasmid mediated genetic exchange are the main reason for the high rate of acquisition of antibiotic resistance. The study was aimed to determine the antibiotic resistance profile of the enterococcal isolates from various clinical samples and to detect the presence of aac (6′) Ie-aph (2″) Ia gene in the isolates which show phenotypic high level gentamicin resistance. Methods: Clinical enterococcal isolates from a tertiary care hospital in southern Delhi were subjected to antibiotic susceptibility testing. MIC for High level gentamicin was measured and the isolates were tested for presence of aac (6′) Ie-aph (2″) Ia gene by PCR. Results: Out of the total 146 Enterococcal isolates, 112 were E. fecalis, 33 were E faecium and 1 was E gallinarum. 26.02% were resistant to High level gentamicin, and 15% were resistant to streptomycin. Vancomycin resistance was 5.4%. 11 E. fecalis and 25 E. faecium isolates showed presence of aac (6′) Ie-aph (2″) Ia gene. Conclusions: High level antibiotic resistance among enterococci and the spread of vancomycin resistant is an issue of serious concern. Isolation rate of E. fecalis was much higher than E. faecium, but aac (6′) Ie-aph (2″) Ia gene was more prevalent in E.faecium. The study highlights spread of the gene aac (6′)-Ie-aph (2″)-Ia among the enterococcal isolates which can be easily transferred to other pathogenic gram positive cocci.
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Background: Enteric fever is predominantly caused by serovars Typhi and Paratyphi of Salmonella enterica. Recently upsurge in multidrug resistant typhoid fever has become a major public health concern in developing countries. This study was conducted to determine the sensitivity pattern of S. Typhi and S. Paratyphi in Southern Delhi. Methods: A total of 98 Salmonella species were isolated over a period of two years between March 2012 – March 2014. Diagnosis of patients was based on clinical features, blood culture and serology. Blood samples were collected and incubated in BacT alert 3D system. Identification was done and antibiotic susceptibility was done by conventional methods and cross checked by Vitek 2 compact system. Results: Of the 98 isolates 87 (88.7 %) were S. Typhi and 11 (11.22%) were S. Paratyphi. Out of 87 samples from which S. Typhi was isolated (68) 78% were male and (19) 21.8% were female patients and they belonged to all age groups. Fever was present in all patients. In this study high resistance was found for both S. Typhi and S. Paratyphi respectively for third generation cephalosporins ( 35.6%, 54.5%), good sensitivity for macrolides (90.8% & 100%) and average sensitivity for ofloxacin (81.6% & 63.7%). Ampicillin and chloramphenicol shows lesser resistance i.e. (11.5% & 18.1%) and (12.6% and 27.2%). 3.5% and 0% resistance was found for imipinem and tigecycline was found 100% sensitive for both S. Typhi and S. Paratyphi, used rarely in treatment of typhoid fever. None of the strains were found sensitive to all drugs. Conclusion: Typhoid bacilli keeps changing its antimicrobial susceptibility pattern. Currently newer drugs like tigecyclline, imipenem and macrolide are showing great response. Primary drugs are showing less resistance may be due to their infrequent usage whereas cephalosporins are showing high resistance towards typhoid bacilli. For better treatment it is important to know the recent susceptibility trend of the area.