Search

Edwardsiella tarda (E. tarda), a gram-negative bacillus, a member of order Enterobacterales , is typically a fish pathogen frequently isolated from fresh and brackish water environments. It is very rarely implicated in human infections such as gastroenteritis (most common), cellulitis, gas gangrene, hepatobiliary infections, peritonitis, empyema, and meningitis. Bacteremia/sepsis caused by E. tarda can be fatal in humans, although very rare (<5%). To date, very few cases of E. tarda sepsis have been reported worldwide including India. We report a rare case of cellulitis caused by E. tarda following fishbone injury in a patient with underlying hematological malignancy leading to sepsis. [ABSTRACT FROM AUTHOR]

Introduction and Objectives The availability of a limited arsenal of antibacterial agents effective against Burkholderia pseudomallei, the causative agent of melioidosis, together with sporadic reports of emergence of resistance necessitates an evaluation of in vitro activity of new antimicrobials against clinical B. pseudomallei isolates. Cefiderocol (CFDC), a novel siderophore cephalosporin, and ceftazidime-avibactam (CZA), a new β lactam combination agent, have shown promising results for the treatment of difficult-to-treat Gram-negative bacilli infections with limited treatment options. This study was conducted to determine the in vitro activity of CFDC and CZA against a contemporary collection of 60 B. pseudomallei clinical isolates. Materials and Methods Minimum inhibitory concentrations (MIC) of CFDC and CZA were determined by broth microdilution and E-test, respectively. The performance of disk diffusion was also evaluated for CFDC. Results All B. pseudomallei isolates were susceptible to CFDC and CZA with MIC range of 0.125 to 2 mg/L and 0.19 to 1 mg/L, respectively. Zone diameters for CFDC ranged from 31 to 40 mm. Conclusion CFDC and CZA exhibited excellent in vitro activity against 60 B. pseudomallei isolates. Further pharmacokinetic-pharmacodynamics studies and clinical trials are needed to prove the clinical efficacy of CFDC and CZA in the treatment of melioidosis. [ABSTRACT FROM AUTHOR]

Objective The performance of Xpert Carba-R assay for the direct identification of carbapenemases directly from positive blood culture vials was evaluated. Materials and Methods In total, 176 positively flagged blood culture vials, yielding carbapenem-resistant GNB (CR-GNB), were enrolled for the detection and differentiation of blaKPC, blaNDM, blaVIM, blaOXA-48, and blaIMP using Xpert Carba-R. Results Klebsiella pneumoniae (76/176, 43.1%), Acinetobacter baumannii complex (67/176, 38%), and Escherichia coli (29/176,16.4%) were the predominant isolates. Overall, NDM production was the commonest (61/176, 34.6%), followed by the co-production of NDM + OXA-48 and the absence of any CR gene (44/176, 25%), followed by OXA-48 (27/176, 15.3%). In CR K. pneumoniae , the co-production of NDM + OXA-48 was most frequent (34/76, 44.7%), whereas in the A. baumannii complex , no CR gene was detected in the majority of isolates (38/67, 56.7%). bla NDM was the commonest gene in E. coli (18/29, 62%) and A. baumannii complex (26/67, 38.8%). Conclusion Xpert Carba-R can identify the molecular mechanism of CR within hours after a blood culture turns positive and, thus, has the potential for optimization of antimicrobial therapy, choosing appropriate novel β-lactam combination agents, as well as infection control interventions. [ABSTRACT FROM AUTHOR]

Granulicatella adiacens , a nutritionally variant Streptococcus (NVS), is part of the normal commensal flora of human mouth, genital, and intestinal tracts and rarely causes disease. It has been mostly reported from bacteremia and endocarditis cases, but rarely can cause vertebral osteomyelitis, pancreatic abscess, otitis media, and endovascular, central nervous system, ocular, oral, bone and joint, and genitourinary infections. Due to requirement of fastidious culture conditions and non-specific colony morphology, serious diagnostic difficulties may arise in cases of NVS infections. Here, we are reporting a rare fatal infection of G. adiacens presented with empyema complicated to sepsis and necrotizing fasciitis. Clinicians should be aware of the pathogenic potential of Granulicatella adiacens (a normal commensal flora of human mouth, genital and intestinal tracts). Appropriate supplemented media and a reliable detection system should be used to identify these fastidious organisms. We present this rare case to bring awareness among clinicians regarding such a rare but potentially fatal infection. [ABSTRACT FROM AUTHOR]

Objective An observational study was conducted to evaluate (1) the incidence rates of infection-related ventilator-associated complication (IVAC) and possible ventilator-associated pneumonia (PVAP) among mechanically ventilated patients of adult medical and surgical intensive care units (ICUs) and (2) the pathogen distribution in patients with PVAP. Materials and Methods The IVAC and PVAP rates of medical and surgical ICUs, between July 1, 2017, and June 30, 2021, per 1,000 mechanical ventilator (MV) days were calculated. The significance of difference in IVAC and PVAP rates between medical and surgical ICUs was calculated. The level of significance was set at less than 0.05. Results MV utilization ratios of adult medical and surgical ICUs were 0.32 and 0.26, respectively (p < 0.001). About 8 and 7 episodes of IVAC and 14 and 6 episodes of PVAP were reported from adult medical and surgical ICUs, accounting for IVAC rates of 3.17 and 1.8 per 1,000 MV (p > 0.05) and PVAP rates of 2.46 and 1.59 per 1,000 MV days in medical and surgical ICUs, respectively (p > 0.05). Acinetobacter baumannii complex either singly or in combination was isolated in 11/20 PVAP cases. Conclusion IVAC and PVAP were more in medical compared with surgical ICUs. The most common pathogen in patients with PVAP was A. baumannii complex. More studies are warranted to monitor the significance of ventilator-associated event on patient outcomes. [ABSTRACT FROM AUTHOR]

Background Spread of carbapenem-resistant Enterobacterales (CRE) is a significant concern in intensive care unit (ICU) settings. Approaches to routine screening for CRE colonization in all ICU patients vary depending on institutional epidemiology and resources. The present study was aimed to evaluate the performance of HiCrome Klebsiella pneumoniae carbapenemase (KPC) agar for the detection of CRE colonization in ICU settings taking the Centers for Disease Control and Prevention (CDC) recommended method as reference. Methods Two-hundred and eighty rectal swabs (duplicate) from 140 patients were subjected to CRE detection in HiCrome KPC agar and MacConkey agar (CDC criteria). Results Using CDC method, total 41 CRE isolates were recovered comprising of 29 Escherichia coli , 11 Klebsiella, and 1 Enterobacter spp. On the other hand, 49 isolates of CRE recovered from 140 rectal swabs using HiCrome KPC agar, out of which 33 were E. coli , 15 Klebsiella, and 1 Enterobacter sp. Statistical Analysis Sensitivity, specificity, negative, and positive predictive values of CRE screening by HiCrome KPC agar were found to be 100% (91.4–100), 91.9% (84.8–95.8), 83.6% (70.9–91.4), and 100% (95.9–100), respectively, taking the CDC recommended method as reference. Conclusion HiCrome KPC agar has high sensitivity in screening CRE colonization. Further studies are needed to establish its applicability for detecting the predominant circulating carbapenemases in the Indian setting. [ABSTRACT FROM AUTHOR]

Objective Challenges in susceptibility testing of colistin along with increase in the prevalence of colistin-resistant carbapenemase-producing Enterobacteriaceae (CRE) pathogens needs addressal. Evaluation of user-friendly methods is necessary as an alternative to broth microdilution (BMD), the reference susceptibility testing method, for routine implementation in diagnostic clinical microbiology laboratories. Genotypic detection of the plasmid-mediated colistin resistance is also needed for infection control purposes. Materials and Methods Colistin susceptibility of 200 nonduplicate clinical CRE isolates from December 2017 to June 2019 was determined by BMD, agar dilution (AD), E test, and rapid polymyxin NP test and interpreted as per the European Committee on Antimicrobial Susceptibility Testing. The results of AD, E test, and NP test were compared with that of BMD, considering minimal inhibitory concentration (MIC) ≤ 2 µg/mL as susceptible and > 2 µg/mL as resistant. Presence of any plasmid-mediated colistin resistance (mcr-1 and 2) was evaluated in 27 colistin-resistant CRE isolates by polymerase chain reaction. Statistical Analysis Performance of different phenotypic methods was analyzed by comparing MIC results of AD and E test with that of reference BMD method. Agreement between BMD and the other two methods was expressed in terms of categorical agreement and essential agreement. Errors were expressed as very major error (VME: false-susceptible) and major error (ME: false-resistance) by AD/E test. VME and ME of 3% disagreement were considered unacceptable. Results Colistin resistance was found in 27 (13.5%) isolates by BMD method. The VME rates of both AD (11%) and E test (37%) could not meet the Clinical and Laboratory Standards Institute recommendation (< 3% VME rate is acceptable) as alternative tests to the reference BMD. Colistin NP test showed sensitivity and specificity of 85% and 98%, respectively. The percentage discordant result in NP test was highest in Enterobacter spp. (17%). None of the 27 colistin resistant isolates showed presence of mcr-1 and mcr-2 genes. Conclusion High VME rate in AD and E tests precludes their use as alternatives to BMD for colistin susceptibility testing. NP test with moderate sensitivity but excellent specificity can be a good alternative for testing colistin susceptibility in CRE isolates, except in Enterobacter spp. Absence of mcr-1 and mcr-2 gene necessitates the exploration of other mechanisms of colistin resistance. [ABSTRACT FROM AUTHOR]