Burkholderia cepacia complex (BCC) is an important nosocomial pathogen in hospitalised patients, particularly those with prior broad-spectrum antibacterial therapy. BCC causes infections that include bacteraemia, urinary tract infection, septic arthritis, peritonitis and respiratory tract infection. Due to high intrinsic resistance and being one of the most antimicrobial-resistant organisms encountered in the clinical laboratory, these infections can prove very difficult to treat and, in some cases, result in death. Patients with cystic fibrosis (CF) and those with chronic granulomatous disease are predisposed to infection by BCC bacteria. BCC survives and multiplies in aqueous hospital environments, including disinfectant agents and intravenous fluids, where it may persist for long periods. Outbreaks and pseudo-outbreaks of BCC septicaemia have been documented in intensive care units, oncology units and renal failure patients. BCC is phenotypically unremarkable, and the complex exhibits an extensive diversity of genotypes. BCC is of increasing importance for agriculture and bioremediation because of their antinematodal and antifungal properties as well as their capability to degrade a wide range of toxic compounds. It has always been a tedious task for a routine microbiological laboratory to identify the nonfermenting gram-negative bacilli, and poor laboratory proficiency in identification of this nonfermenter worldwide still prevails. In India, there are no precise reports of the prevalence of BCC infection, and in most cases, these bacteria have been ambiguously reported as nonfermenting gram-negative bacilli or simply Pseudomonas spp. The International Burkholderia cepacia Working Group is open to clinicians and scientists interested in advancing knowledge of BCC infection/colonisation in persons with CF through the collegial exchange of information and promotion of coordinated approaches to research.

There has been re-emergence of susceptibility to first line antibiotics and a notable decline in MDR strains of S. Typhi. We have a very high resistance to NA and decreasing susceptibility to ciprofloxacin. Third generation cephalosporins and azithromycin seem to be effective therapeutic options. Judicious use of these antibiotics is mandatory to prevent emergence of resistant strains.

PURPOSE: This study has been done to speciate coagulase-negative staphylococci (CoNS) and also study their antibiotic susceptibility pattern isolated from clinical samples. MATERIALS AND METHODS: A total of 120 consecutive CoNS were isolated from various clinical samples such as blood, pus, wound swab, drain fluid, tracheal aspirate, peritoneal fluid, and pleural fluid over a period of 6 months. CoNS were identified by characteristic growth on media such as Blood agar and MacConkey agar. Speciation and identification were done by a range of biochemical testing such as PYR broth hydrolysis, novobiocin resistance, polymyxin B sensitivity, and then by matrix-assisted laser desorption ionization-time of flight. Antibiotic susceptibility of the isolates was done by Kirby-Bauer disk diffusion method as per CLSI 2017 guidelines. RESULTS: Among the 120 isolates, the most common species was Staphylococcus epidermidis (56.67%) followed by Staphylococcus haemolyticus (21.67%), Staphylococcus lugdunensis (11.67%), Staphylococcus caprae (5%), Staphylococcus cohnii (3.33%), and finally Staphylococcus vitulinus (1.67%). Good in vitro susceptibility was noted toward linezolid (100%), vancomycin (100%), teicoplanin (100%), and doxycycline (80.2%). The antibiotics to which resistance was seen were penicillin (96.5%), ciprofloxacin (57.1%), and oxacillin (45.5%). MR CoNS in our study ranged from 50% to 68.67%. CONCLUSION: Antibiotic resistance in CoNS is increasing toward penicillin, ciprofloxacin, and oxacillin as found in our study. The antibiotics such as vancomycin, teicoplanin, linezolid, and doxycycline which showed good in vitro susceptibility, therefore, should be kept as reserve drugs and used judiciously.

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Different susceptibility testing methods for polymyxins show great variation in their results and BMD using glass-coated plates can be considered the best candidate for gold standard.

Burkholderia cenocepacia is a clinically dominant form among the other virulent species of Burkholderia cepacia complex (Bcc). In the present study, we sequenced and analyzed the genomes of seven nosocomial Bcc isolates, five of which were isolated from the bloodstream infections and two isolates were recovered from the hospital setting during the surveillance. Genome-based species identification of the Bcc isolates using a type strain explicitly identified the species as B. cenocepacia. Moreover, single nucleotide polymorphism analysis revealed that the six isolates were clonal and phylogenetically distinct from the other B. cenocepacia. Comparative genomics distinctly revealed the larger genome size of six clonal isolates as well as the presence of a novel 107 kb genomic island named as BcenGI15, which encodes putative pathogenicity-associated genes. We have shown that the BcenGI15 has an ability to actively excise from the genome and forming an extrachromosomal circular form suggesting its mobile nature. Surprisingly, a homolog of BcenGI15 was also present in the genome of a clinical isolate named Burkholderia pseudomallei strain EY1. This novel genetic element is present only in the variants of B. cenocepacia and B. pseudomallei isolates suggesting its interspecies existence in the main pathogenic species of the genus Burkholderia. In conclusion, the whole genome analysis of the genomically distinct B. cenocepacia clinical isolates has advanced our understanding of the epidemiology and evolution of this important nosocomial pathogen as well as its relatives.

Stenotrophomonas maltophilia, once regarded as an organism of low virulence, has evolved as a significant opportunistic pathogen causing severe human infections in both hospital and community settings, especially amongst highly debilitated patients. Globally, S. maltophilia ranks third amongst the four most common pathogenic non-fermenting Gram-negative bacilli (NFGNBs), others being Pseudomonas aeruginosa, Acinetobacter baumannii and Burkholderia cepacia complex (Bcc). The worth of accurate identification of S. maltophilia comes to the forefront as it needs to be differentiated from other NFGNBs such as Acinetobacter, P. aeruginosa and Bcc due to its inherently contrasting antibiotic susceptibility pattern. Consequently, its correct identification is essential as no single drug is amply effective against all NFGNBs, which hinders initiation of appropriate empirical treatment resulting in increased morbidity and mortality.

We recently read an article on carbapenem susceptibility testing errors in studies that used three automated systems, disk diffusion (DD), Etest (ET), and broth microdilution (BMD), to investigate Acinetobacter baumannii-calcoaceticus complex (ABC) isolates (1). The authors concluded from the study that the manual methods are more accurate than automated methods. The error rates for testing susceptibility to imipenem and meropenem by DD and the Etest were found to be within an acceptable range compared with MIC detected by BMD. Carbapenems are widely used against multidrug-resistant (MDR) ABC isolates (2). However, the pathogen is associated with increasing carbapenem resistance, which limits therapeutic options and challenges effective hospital infection control. Thus, as antimicrobial resistance increases, accurate susceptibility testing to guide therapeutic options is essential. Agar microdilution and broth microdilution for detecting carbapenem resistance are the recommended methods, but they are impractical to implement as routine tests in many clinical laboratories with a high isolate load that cannot afford automated susceptibility testing or the Etest. The Kirby-Bauer disk diffusion (KBDD) method is more economical and the standardized one used for testing susceptibility to most of the antibiotics. However, only a few studies have provided data on its reliability for testing carbapenems against ABC isolates (1, 3).In the present study, the KBDD method using discs (10 g each) of imipenem (BD), meropenem (Hi-Media), and doripenem (BD) was compared with the bioMérieux Etest (0.002 to 32 g/ml) on 124 nonrepeat MDR ABC strains isolated from blood, respiratory, and pus specimens. The isolates were identified using standard bacteriological procedures (4), and interpretation of susceptibility testing was done according to CLSI guidelines (5). Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853 were used as the quality control strains. Taking the Etest as the reference, discordance between it and the KBDD method was categorized as a very major error (reported susceptible when resistant), a major error (reported resistant when susceptible), or a minor error (reported intermediate when resistant or susceptible or vice versa). By the use of CLSI and FDA breakpoints for imipenem and meropenem, no discrepancy was found between the KBDD method and the Etest in the case of imipenem. However, in the case of meropenem, nine strains that were resistant by the KBDD method came out to be intermediately sensitive by the Etest. Thus, the KBDD method showed a minor error rate of 7.3% and no very major or major error for meropenem was recorded, which is acceptable. CLSI does not provide breakpoints for doripenem, but when the same breakpoints used for imipenem and meropenem were applied to doripenem, a major error of 2.5% and a minor error of 21.8% were observed, proving the lower accuracy rate of the KBDD method. According to EUCAST breakpoints (Table 1), no discrepancy was found between the KBDD method and the Et...