Kamini Walia

Antibiotic resistance and its containment in India

Manish Kakkar and colleagues discuss factors contributing to antibiotic resistance in India, and examine policy initiatives to address it

Molecular Characterization of Invasive Carbapenem- Resistant Acinetobacter baumannii from a Tertiary Care Hospital in South India

IntroductionAcinetobacter baumannii is an important opportunistic pathogen responsible for causing nosocomial infections. Carbapenems are considered to be the drug of choice to treat infections caused by multidrug-resistant A. baumannii. The prevalent mechanism of carbapenem resistance in A. baumannii is enzymatic degradation by β-lactamases. Therefore, the aim of the study is to determine the prevalence and distribution of molecular determinants among the clinical isolates of carbapenem-resistant A. baumannii.MethodsA total of 103 consecutive, non-duplicate carbapenem-resistant A. baumannii isolated from blood and endotracheal aspirates (ETAs) were included in the study. The CarbAcineto NP test was performed for the screening of carbapenemase production. Polymerase chain reaction (PCR) was performed to detect extended spectrum β-lactamases (ESBLs), metallo-β-lactamases (MBLs) and oxacillinases (OXAs). PCR was done for the detection of ISAba1 elements, and mapping PCR was performed to identify the position of ISAba1 with respect to the OXA-23-like gene.ResultsAmong the 103 A. baumannii isolates, 94 were phenotypically identified as carbapenemase producers. blaPER was the most common among the ESBLs. Among MBLs, blaNDM was predominant followed by the blaVIM gene. blaOXA-51 and blaOXA-23 were the most common and present in all 103 isolates. Almost 80% of the isolates had ISAba1 upstream blaOXA-23 gene.ConclusionThe blaOXA-23 and blaNDM genes are the most common type of oxacillinases and metallo β-lactamases, respectively, and contribute to carbapenem resistance in clinical isolates of A. baumannii. The presence of ISAba1 upstream of the blaOXA-23 gene suggests that the insertion element acts as a promoter for its increased expression.FundingIndian Council of Medical Research, New Delhi, India (ref. no. AMR/TF/54/13ECDHII dated 23 October 2013).

Five-year profile of candidaemia at an Indian trauma centre: High rates of Candida auris blood stream infections

Candidaemia is a potentially fatal infection with varied distribution of Candida species and their antifungal susceptibility profiles. The recent emergence of Candida auris in invasive candidiasis is a cause for concern. This study describes the profile of candidaemia at an Indian tertiary care hospital and reports the emergence of C. auris. All patients diagnosed with candidaemia between 2012 and 2017 were studied. The isolates were identified using conventional methods, VITEK 2 and MALDI‐TOF MS. The isolates not identified by MALDI‐TOF were sequenced. Antifungal susceptibility testing was done by the CLSI broth microdilution method and VITEK 2. A total of 114 isolates of Candida species were analysed. Candida tropicalis (39.4%) was the most common species, followed by C. auris (17.5%), C. albicans (14%) and C. parapsilosis (11.4%). Notably, Diutina mesorugosa isolates (n = 10) were not identified by MALDI‐TOF and were confirmed by sequencing. Furthermore, 45% (n = 9) C. auris strains exhibited low MICs of FLU (0.05‐4 μg/mL) and the remaining 55% (n = 11) isolates had high MICs ≥ 64 μg/mL. Also, D. mesorugosa exhibited high MICs of FLU (32 μg/mL) in 2 isolates. A high rate of errors in antifungal susceptibility was noted with the VITEK 2 as compared to the CLSI method. Candida auris was the second most prevalent species causing candidaemia warranting infection control practices to be strengthened to prevent its spread.

Molecular Characterization of Intermediate Susceptible Typhoidal Salmonella to Ciprofloxacin, and its Impact

Background and ObjectiveExtensive use of ciprofloxacin to treat Salmonella typhi infections has led to the emergence of resistance, resulting in clinical failure and delayed treatment response. Interpretative breakpoints for ciprofloxacin were revised by the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) in 2012. Since the majority of S. typhi isolates fall under the category of ‘intermediate susceptible’ as per CLSI criteria, we undertook molecular characterization to better define the susceptibility of these isolates.MethodsOf 113 typhoidal Salmonella isolates collected during 2014, 33 (27 S. typhi and 6 S. paratyphi A) were randomly selected to determine the presence of chromosomal (gyrA, gyrB and parC), plasmid (qnrA, qnrB, qnrS and aac(6′)-lb-cr), and efflux-mediated fluoroquinolone resistance.ResultsTo the best of our knowledge, the parC mutation Glu(84)-Gly was observed for the first time in S. typhi in India. Of 33 isolates, only one harbored the qnrB gene, which is responsible for plasmid-mediated resistance. No significant change in efflux pump activity was observed for ciprofloxacin, except one that showed a fivefold decrease. Ninety-six percent of isolates with intermediate minimum inhibitory concentration to ciprofloxacin (CLSI) had mutations in the gyrA and parC genes, which might translate to possible/probable clinical failure in patients if treated with ciprofloxacin. In contrast, the EUCAST criteria define these isolates as resistant and may result in appropriate therapy with reduced morbidity.ConclusionIt was clear that the molecular mechanism of ciprofloxacin resistance correlates better with the EUCAST criteria than the CLSI criteria, which is also in agreement with the pefloxacin results, suggesting it as a surrogate marker for identifying fluoroquinolone susceptibility.

Molecular characterisation of antimicrobial resistance in Pseudomonas aeruginosa and Acinetobacter baumannii during 2014 and 2015 collected across India

Background: Surveillance of antimicrobial resistance (AMR) is of great importance. Pseudomonas aeruginosa and Acinetobacter baumannii are important pathogens and emergence of resistance in these have increased the morbidity and mortality rates. This surveillance study was initiated by the Government of India - Indian Council of Medical Research. The aim of this study is to determine the antimicrobial susceptibility profile and to characterise the enzyme mediated antimicrobial resistance such as extended spectrum beta-lactamases (ESBLs) and carbapenemases among multidrug-resistant (MDR) P. aeruginosa and A. baumannii. Materials and Methods: A multi-centric study was conducted from January 2014 to December 2015 with a total number of 240 MDR P. aeruginosa and 312 MDR A. baumannii isolated from blood, cerebrospinal fluid, respiratory, pus, urine and intra-abdominal infections. Kirby–Bauer disc diffusion was done to determine the antimicrobial susceptibility profile. Further, MDR isolates were characterised by multiplex polymerase chain reaction to determine the resistance genes for ESBLs and carbapenemases. Results: Among the ESBLs, blaVEB (23%), blaTEM (5%) and blaSHV (0.4%) in P. aeruginosa and blaPER (54%), blaTEM (16%) and blaSHV (1%) in A. baumannii were the most prevalent. Likewise, blaVIM (37%), blaNDM (14%), blaGES (8%) and blaIMP (2%) in P. aeruginosa and blaOXA-23like (98%), blaOXA-58like (2%), blaNDM (22%) and blaVIM (3%) in A. baumannii were found to be the most prevalent carbapenemases. blaOXA-51like gene, intrinsic to A. baumannii was present in all the isolates tested. Conclusion: The data shown highlight the wide difference in the molecular mechanisms of AMR profile between P. aeruginosa and A. baumannii. In P. aeruginosa, plasmid-mediated mechanisms are much lesser than the chromosomal mediated mechanisms. In A. baumannii, class D oxacillinases are more common than other mechanisms. Continuous surveillance to monitor the trends in AMR among MDR pathogens is important for implementation of infection control and to guide appropriate empirical antimicrobial therapy.

Antimicrobial stewardship programme (AMSP) practices in India

A survey was conducted to ascertain practice of antimicrobial stewardship programme (AMSP) in India for 2013. A total of 20 health care institutions (HCI) responded to a detailed questionnaire. All the institutions contacted were tertiary care HCI, of which 12 were funded by government (GHCI) and 8 were corporate/private HCI (PHCI). Further, all catered to both rural and urban populations and were spread across the country. Written documents were available with 40 per cent for AMSP, 75 per cent for hospital infection control (HIC) and HIC guidelines and 65 per cent for antimicrobial agents (AMA) prescription guidelines. Records were maintained for health care associated infections (HCAI) by 60 per cent HCI. Antimicrobial resistance (AMR) data were being analysed by 80 per cent HCI. AMA usage data were analysed by only 25 per cent HCI and AMA prescription audit and feedback by 30 per cent. PHCI performed better than GHCI across all fields of AMSP. The main contributory factor was possibly the much higher level of accreditation of PHCI hospitals and their diagnostic laboratories. The absence of infectious diseases physicians and clinical pharmacists is worrying and demands careful attention.

Draft Genome Sequence of Extremely Drug-Resistant Pseudomonas aeruginosa (ST357) Strain CMC_VB_PA_B22862 Isolated from a Community-Acquired Bloodstream Infection

ABSTRACT Extremely drug-resistant Pseudomonas aeruginosa strains causing severe infections have become a serious concern across the world. Here, we report draft genome sequence of P. aeruginosa with an extremely drug-resistant profile isolated from a patient with community-acquired bloodstream infection in India.

Research priorities for HIV/M. tuberculosis co-infection

MS is funded by the EU; AM is funded by the EU and the Bill and Melinda Gates foundation. The EUCO-Net project leading to these results has received funding from the European Communitys Seventh Framework Programme.

Spectrum of Gut Immunologic Reactions:Selective Induction of Distinct Responses to Vibrio cholerae WO7 and Its Toxin

Past studies with Vibrio cholerae have shown that cholera toxin (CT) is mainly responsible for inducing T helper type 2 (Th2) responses with systemic IgG1, IgE and mucosal secretory IgA (sIgA) antibodies. In this study, V. cholerae WO7, which produces novel toxin unrelated to CT, was given orally to mice in order to determine whether the strain V. cholerae WO7 differs from V. cholerae 569B, which produces CT, in the nature of responses generated at the gut and splenic level. The analysis of immune responses evoked by V. cholerae WO7 in the gut of mice revealed striking differences as compared to those elicited by V. cholerae 569B infection. To assess the T helper cell type responses, lymphocytes from Peyers patches and the spleen were stimulated in vitro for studying the cytokine patterns. PP and SP lymphoid cells from V. cholerae WO7 infected animals elaborated significant amounts of IL‐2, IFN‐γ and IL‐12 by 7 days p.i., suggesting a Th1 type of response. However by 15 days p.i., the PP and SP lymphoid cells secreted only IL‐6 and IL‐10 with traces of IFN‐γ. On the other hand, infection with V. cholerae 569B yielded mainly Th2 type responses at Peyers patches as well as the splenic level. Infection with both V. cholerae WO7 and 569B induced toxin‐specific IgA secreting cells at the gut and splenic level along with IgG1 secreting cells, indicating that both V. cholerae WO7 and 569B evoke an antigen‐specific Th2 type of response in the gut as well as spleen. The persistence of IgA along with Th1‐type cytokines indicates an alternate induction mechanism since mucosal IgA responses are usually associated with Th2‐type responses. These observations are suggestive of a common mechanism employed by the host to clear different strains of V. cholerae infection (569B and WO7 in this case), while the nature of toxins elaborated failed to modulate the net outcome of the infection caused by V. cholerae.

First Indian report of IncX3 plasmid carrying blaNDM-7 in Escherichia coli from bloodstream infection: potential for rapid dissemination

Enterobacteriaceae with blaNDM-7 is only infrequently observed. Self-transmissible plasmids carrying the blaNDM gene increase the dissemination of carbapenem resistance in developing countries. This study investigates the whole genome sequence of a blaNDM-7-positive Escherichia coli. The isolate was an extended-spectrum β-lactamase producer by combined disc diffusion test and carbapenemase producer by CarbaNP method. Sequencing results revealed the isolate as E. coli ST-167 with IncX3 plasmid carrying blaNDM-7 in addition to blaTEM-1 and blaCMY-42 genes. The identification of IncX3-blaNDM-7 combination is the first report in India where blaNDM-7 is known to cause higher resistance to carbapenems compared to its variants.