Accurate identification and epidemiological characterization of Burkholderia cepacia complex : an update

Bacteria belonging to the Burkholderia cepacia complex (Bcc) are among the most important pathogens isolated from cystic fibrosis (CF) patients and in hospital acquired infections (HAI). Accurate identification of Bcc is questionable by conventional biochemical methods. Clonal typing of Burkholderia is also limited due to the problem with identification. Phenotypic identification methods such as VITEK2, protein signature identification methods like VITEK MS, Bruker Biotyper, and molecular targets such as 16S rRNA, recA, hisA and rpsU were reported with varying level of discrimination to identify Bcc. rpsU and/or 16S rRNA sequencing, VITEK2, VITEK MS and Bruker Biotyper could discriminate between Burkholderia spp. and non-Burkholderia spp. Whereas, Bcc complex level identification can be given by VITEK MS, Bruker Biotyper, and 16S rRNA/rpsU/recA/hisA sequencing. For species level identification within Bcc hisA or recA sequencing are reliable. Identification of Bcc is indispensable in CF patients and HAI to ensure appropriate antimicrobial therapy

Cancer selective cytotoxicity of Sida acuta extracts on Artemia salina and human breast adenocarcinoma cells

Cancer is one of the major causes of morbidity and mortality globally. The interests in the use of plants or plant-derived compounds are increasing recently due to their promising results in chemoprevention. The present study investigates the anti-cancer potentials of Sida acuta, a traditionally well-known medicinal plant. Accordingly, the methanol and aqueous extracts of S. acuta (SAM and SAA) were tested against Artemia salina nauplii for toxicity and on MDA-MB-231 and MCF-7 human breast adenocarcinoma cell lines for cytotoxic and apoptotic properties. Both the extracts, SAM and SAA exhibited higher toxicity towards Artemia salina. Interestingly, the extracts exhibited minimal cytotoxicity in normal cells (VERO) than in human breast cancer cells (MDA-MB-231 and MCF-7). The highly active SAA successfully induced apoptosis in MDA MB 231 and MCF-7 cells showing 17.81% and 4.27% of late apoptotic cells and 27.14% and 37.32% of early apoptotic cells, respectively. Most of the drugs being developed from plant sources had landed successfully in clinical trials. In conclusion, the observations clearly suggest that SAA may have possible therapeutic potential against human breast cancer-derived diseases specifically against ER-positive breast cancer

First Indian report on genome-wide comparison of multidrug-resistant Escherichia coli from blood stream infections.

BACKGROUND: Multidrug-resistant (MDR) E. coli with extended-spectrum β-lactamases (ESBLs) is becoming endemic in health care settings around the world. Baseline data on virulence and antimicrobial resistance (AMR) of specific lineages of E. coli circulating in developing countries like India is currently lacking. METHODS: Whole-genome sequencing was performed for 60 MDR E. coli isolates. The analysis was performed at single nucleotide polymorphism (SNP) level resolution to identify the presence of their virulence and AMR genes. RESULTS: Genome comparison revealed the presence of ST-131 global MDR and ST410 as emerging-MDR clades of E. coli in India. AMR gene profile for cephalosporin and carbapenem resistance differed between the clades. Genotypes blaCTX-M-15 and blaNDM-5 were common among cephalosporinases and carbapenemases, respectively. For aminoglycoside resistance, rmtB was positive for 31.7% of the isolates, of which 95% were co-harboring carbapenemases. In addition, the FimH types and virulence gene profile positively correlated with the SNP based phylogeny, and also revealed the evolution of MDR clones among the study population with temporal accumulation of SNPs. The predominant clone was ST167 (blaNDM lineage) followed by ST405 (global clone ST131 equivalent) and ST410 (fast spreading high risk clone). CONCLUSIONS: This is the first report on the whole genome analysis of MDR E. coli lineages circulating in India. Data from this study will provide public health agencies with baseline information on AMR and virulent genes in pathogenic E. coli in the region

First report on a cluster of colistin-resistant Klebsiella pneumoniae strains isolated from a tertiary care center in India : whole-genome shotgun sequencing

Klebsiella pneumoniae is a nosocomial pathogen with clinical importance due to its increasing resistance to carbapenems and colistin. Here, we report the genome sequences of eight colistin-resistant K. pneumoniae strains which might help in understanding the molecular mechanism of the species. The sequence data indicate genomes of ~5.2 to 5.4 Mb, along with several plasmids

Divergent evolution of Corynebacterium diphtheriae in India: An update from National Diphtheria Surveillance network.

Diphtheria is caused by a toxigenic bacterium Corynebacterium diphtheria which is being an emerging pathogen in India. Since diphtheria morbidity and mortality continues to be high in the country, the present study aimed to study the molecular epidemiology of C. diphtheriae strains from India. A total of 441 diphtheria suspected specimens collected as part of the surveillance programme between 2015 and 2020 were studied. All the isolates were confirmed as C. diphtheriae with standard biochemical tests, ELEK's test, and real-time PCR. Antimicrobial susceptibility testing for the subset of isolates showed intermediate susceptibility to penicillin and complete susceptible to erythromycin and cefotaxime. Isolates were characterized using multi locus sequence typing method. MLST analysis for the 216 C. diphtheriae isolates revealed major diversity among the sequence types. A total of 34 STs were assigned with majority of the isolates belonged to ST466 (30%). The second most common ST identified was ST405 that was present in 14% of the isolates. The international clone ST50 was also seen. The identified STs were grouped into 8 different clonal complexes (CC). The majority belongs to CC5 followed by CC466, CC574 and CC209, however a single non-toxigenic strain belongs to CC42. This epidemiological analysis revealed the emergence of novel STs and the clones with better dissemination properties. This study has also provided information on the circulating strains of C. diphtheriae among the different regions of India. The molecular data generated through surveillance system can be utilized for further actions in concern

Exploring indoor and outdoor dust as a potential tool for detection and monitoring of COVID-19 transmission

This study investigated the potential of using SARS-CoV-2 viral concentrations in dust as an additional surveillance tool for early detection and monitoring of COVID-19 transmission. Dust samples were collected from 8 public locations in 16 districts of Bangkok, Thailand, from June to August 2021. SARS-CoV-2 RNA concentrations in dust were quantified, and their correlation with community case incidence was assessed. Our findings revealed a positive correlation between viral concentrations detected in dust and the relative risk of COVID-19. The highest risk was observed with no delay (0-day lag), and this risk gradually decreased as the lag time increased. We observed an overall decline in viral concentrations in public places during lockdown, closely associated with reduced human mobility. The effective reproduction number for COVID-19 transmission remained above one throughout the study period, suggesting that transmission may persist in locations beyond public areas even after the lockdown measures were in place

A case of clinical and microbiological failure of azithromycin therapy in Salmonella enterica serotype Typhi despite low azithromycin MIC

Typhoid fever remains a serious problem in many developing countries. Due to resistance to multiple first line drugs, azithromycin has evolved as an important drug in the treatment of typhoid. While therapy with azithromycin is highly effective, no clinically validated mean inhibitory concentration (MIC) break points or disc diffusion cutoff guidelines are available so far. We describe an Indian adult with clinical and microbiological failure to azithromycin despite low azithromycin MIC

Accurate differentiation of Escherichia coli and Shigella serogroups: challenges and strategies

Shigella spp. and Escherichia coli are closely related; both belong to the family Enterobacteriaceae. Phenotypically, Shigella spp. and E. coli share many common characteristics, yet they have separate entities in epidemiology and clinical disease, which poses a diagnostic challenge. We collated information for the best possible approach to differentiate clinically relevant E. coli from Shigella spp. We found that a molecular approach is required for confirmation. High discriminatory potential is seen with whole genome sequencing analysed for k-mers and single nucleotide polymorphism. Among these, identification using single nucleotide polymorphism is easy to perform and analyse, and it thus appears more promising. Among the nonmolecular methods, matrix-assisted desorption ionization–time of flight mass spectrometry may be applicable when data analysis is assisted with advanced analytic tools. Keywords: 16S rRNA, k-mer, MALDI-TOF MS, single nucleotide polymorphism, whole genome sequencin