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Background: Carbapenem resistant K.pneumoniae (CRKp) are posing an increasing presenting a threat to treatment of infections especially in children and immunocompromised patients. Recently there are cases with hypervirulent/hypermucoviscous K.pneumoniae (hvKp) infections associated with high mortality rates of 52% and metastatic spread. Hence it is important to know the factors contributing to disease severity inhvKpinfections. There are limited reports regarding carbapenem susceptibility of hvKp which however is an important factor contributing to patient outcome. We aimed at studying the prevalence of genes coding for carbapenamases among hvKp and distribution of meropenem MIC among hvKp and non-hvKp. Methods & Materials: A total of 77 CRKp isolated from blood culture during 2014 and 2015 at department of Clinical Microbiology, CMC, were included. Screening for carbapenem resistance was done by disc diffusion method for susceptibility to imipenem and meropenem and resistant isolates were included which were then subjected to E-test for meropenem. The results for antimicrobial susceptibility testing were interpreted according to CLSI guidelines. The resistant isolates were then subjected to string test which is the phenotypic test for hvKp, and multiplex PCR for detection of genes for carbapenemase production. Results: Among the 77 CRKp isolates tested, 25 (32%) were string test positive and 52 (68%) were negative. The majority of hvKp, 10 (40%), co-expressed NDM and OXA48-like genes while 19 (37%) non-hvKp expressed OXA48-like. Meropenem MIC range obtained was 0.0647#956;g/ml - >32#956;g/ml. 72% and 65% of hvKp and non-hvKp had MIC of ≥32#956;g/ml. Overall, OXA48-like genes were the most predominant genes isolated from 25 (32%) isolates tested. Conclusion: Co-expression of NDM and OXA48-like genes might contribute to the increased MIC for meropenem among the hvKp which is a potential threat for patient management. Monitoring the frequency of isolation and susceptibility profile for hvKp will help in achieving clinical cure by administering the right antibiotic and prevention of metastatic spread of infection. Decreased susceptibility and the hypermucoviscous nature might contribute to the severity of infection and increased mortality in infections with hvKp than the classical K.pneumoniae. [ABSTRACT FROM AUTHOR]

Background: Shigellae are the causative agents of bacillary dysentery, represents a significant public health problem worldwide especially in developing countries. New serotypes or subserotypes in Shigella are not uncommon and are reported from different parts of the world. Notably, atypical Shigella exhibit greater antibiotic resistance than typical Shigella serotypes and also found to harbour integrons which has the ability to acquire resistance genes. The purpose of this work was to amplify rfb regions (contains the genes coding for the enzymes responsible for O-antigen synthesis) of non-agglutinating Shigella isolates to characterize these by endonuclease restriction and to study the presence of antimicrobial resistance genes (AMR). Methods & Materials: A total of 3647 faeces specimens were processed between January to December 2014, among these, 27.5% (n = 176) were identified as Shigella spp. Eight non-agglutinable Shigella isolates obtained were included in the study for molecular characterization. These strains were tested for their antimicrobial susceptibility against six antibiotics by Kirby Bauer disc diffusion method. All the isolates were screened for the AMR genes (dhfr1A, sulII, bla-OXA, bla-TEM, bla-CTX-M, AmpC and qnrA,B,S) by PCR. The isolates were also amplified for their O-antigen gene cluster using Expand long template PCR system and the amplicons were further restricted using MboII enzyme. Results: The prevalence of shigellosis during the study period was 4.8%. The antimicrobial resistance for the atypical Shigella were 50% for ampicillin, co-trimoxazole (87%), nalidixic acid (37%), cefixime (12.5%) and all were susceptible to norfloxacin and cefotaxime. The AMR gene PCR results showed 25% of dhfr1A (n = 2), 62.5% sulII (n = 5), 50% bla-TEM (n = 4), 50% qnrS (n = 4) and all the isolates were negative for bla-OXA, bla-CTX-M and AmpC genes. rfb- RFLP results showed clearly identifiable and reproducible pattern, six different patterns were obtained. Conclusion: This study revealed the description of O-specific patterns allowing serotype identification without the use of antisera. Although the number of atypical Shigella strains in this study was only eight, thorough and strict monitoring of isolation of such atypical strains would help to understand the actual disease burden caused by the new Shigella serovars and consequently to study the epidemiology of shigellosis. [ABSTRACT FROM AUTHOR]