Carbapenem-resistance among enterobacteriaceae has become a global health concern. The objective of this study was to understand NDM producing enterobacteriaceae and their genetic basis of resistance, spreading in neonatal intensive care unit. Carbapenem resistant NDM producing enterobacteriaceae isolates were recovered from rectal swab and blood sample of infants admitted in NICU. These were determined by using Carba-NP test. All isolates were identified using BD PhoenixTM−100 and MICs were determined by broth microdilution method. The blaNDM and associated resistant markers were checked by PCR followed by sequencing. Moreover, ERIC-PCR and genetic environment of blaNDM gene were also performed for the analysis of clonal relationship and genetic surrounding of the strains. We characterized 44 isolates with blaNDM variants in Escherichia coli (45.5%), Klebsiella pneumoniae (40.9%), Citrobacter freundii (4.5%), Citrobacter braakii (2.3%), Klebsiella oxytoca (2.3%), Enterobacter cloacae (2.3%), Enterobacter aerogenes (2.2%) from NICU, showing resistance against all antibiotics except colistin and polymixin B. ISAba125 and bleomycin gene were found surrounding all blaNDM variants, besides class I integron on plasmid. (ERIC)-PCR data revealed non-clonal relatedness among most of the isolates. The transfer of resistant markers was confirmed by conjugation experiment. The PCR-based replicon typing was carried out using DNA of transconjugants. These isolates carried NDM-1 (20.45%), NDM-4 (36.36%), NDM-5 (38.64%), NDM-7 (4.55%), along with OXA, CMY, and SHV variants on conjugative plasmid of IncFIA, IncFIC, IncF, IncK, IncFIB, IncB/O, IncHI1, IncP, IncY, IncFIIA, IncI1, and IncN types. An increased number of carbapenem-resistant NDM producing enterobacteriaceae isolates recovered from NICU which is alarming signal for health workers and policy makers. Hence, it is utmost important to think about infection control measures.

Objective Gestational diabetes mellitus (GDM) is associated with adverse perinatal outcomes and is an independent risk factor for vaginal dysbiosis. Understanding the vaginal microbiota in health and disease is essential to screen, detect, and manage complications of pregnancy. Therefore, the aims of the present study were to assess and compare vaginal dysbiosis in pregnancy in women with and without GDM and examine its impact on perinatal outcomes in our population. Methods The present study was a prospective cohort study recruiting pregnant women. The subjects were divided into two groups (GDM and non‐GDM) and were followed until delivery to assess fetomaternal outcomes. Vaginal samples were collected at 24–28 weeks and 34–38 weeks for Nugent scoring and determination of bacterial and fungal species. Results The study recruited 502 pregnant women, with a final assessment of 320 mother–infant pairs (GDM n = 134; non‐GDM n = 186). We found a significant association of vaginal dysbiosis with GDM and adverse perinatal outcomes. Significant differences were also seen in status of infection and its trimester‐wise changes in relation to hyperglycemia. Conclusion By defining an association of vaginal dysbiosis with GDM and its correlation with perinatal outcomes, the present study calls for exploitation of this potential association as a new target in the prevention and treatment of GDM and in alleviating their undesired maternal and infant outcomes.

No abstract

Aim: To propose newer combinations of antibiotics effective against NDM-1-producing bacterial strains. Materials & methods: Antibiotics combinations were tested by checkerboard assay. NDM-1 protein/enzyme was expressed and purified to perform enzyme kinetics, circular dichroism and fluorescence spectroscopic studies. Results: Doripenem–cefoxitin combination and doripenem–tetracycline combination showed synergistic effect toward NDM-1-producing strains. The catalytic efficiency of NDM-1 enzyme was decreased drastically by 96.6% upon doripenem–cefoxitin treatment and by 35.54% after doripenem–tetracycline treatment. Conformational changes were observed in NDM-1 upon combination treatment. Conclusion: NDM-1-producing bacterial strains show resistance to multiple antibiotics but the combination of doripenem–cefoxitin and doripenem–tetracycline are effective against them. The combination of a carbapenem and cephamycin antibiotic is proposed for future treatment options against bacteria-producing NDM-1.

Members of Enterobacteriaceae cause antibiotic-resistant infections worldwide. One such marker, CTX-M-15, expressed by Enterobacteriaceae produces b-lactamases, which hydrolyze the cephalosporin group of antibiotics, such as cefotaxime, used in the treatment of both Gram-positive and negative bacterial infections. Amino acid residues present in close proximity of the active site might also play a major role in the structure and function of CTX-M-15, hence the objective of this study was to investigate the significance of two amino acid residues, Asn-247 and Arg-64, present near to the active site in the hydrolysis of cefotaxime. bla CTX-M-15 , cloned from the E. cloacae strain, and using Polymerase Chain Reaction (PCR)-based site-directed mutagenesis, Asn247Val and Arg64Leu mutations were introduced.The minimum inhibitory concentrations of cefotaxime for the CTX-M-15 (N247V) and CTX-M-15 (R64L) mutants were reduced by 512 and 128 fold, respectively. Proteins/enzymes of wild-type CTX-M-15, CTX-M-15 (N247V) and CTX-M-15 (R64L) mutants were expressed and purified. Kinetic studies showed that the catalytic efficiencies of the N247V mutant and R64L mutant enzymes in the hydrolysis of cefotaxime were reduced by 89.66% and 71.11%, respectively. Circular dichroism spectroscopic studies showed considerable changes in the a-helical content of the mutant enzymes. A fluorescence study showed that N247V mutant-cefotaxime and R64L mutant-cefotaxime underwent complex formation with strong interactions. The study provides an understanding of the crucial role of the amino acid residues asparagine 247 and arginine 64 present in close proximity of the active site in the hydrolytic mechanism of CTX-M-15 type b-lactamases. Hence, Asn-247 and Arg-64 can be used as potential target sites for the design of inhibitory molecules against CTX-M-15-producing bacterial strains. Fig. 8 The structure of the CTX-M-15 enzyme with the active site highlighted (purple circle) and near the active site residues Asn-247 (panel (A)) present at 9.7Å distance from the active site and Arg-64 (panel (B)) present at 18.8Å distance from the active site.This journal is