The SARS-CoV-2 B.1.617.2 (Delta) variant was first identified in the state of Maharashtra in late 2020 and spread throughout India, outcompeting pre-existing lineages including B.1.617.1 (Kappa) and B.1.1.7 (Alpha) 1 . In vitro, B.1.617.2 is 6-fold less sensitive to serum neutralising antibodies from recovered individuals, and 8-fold less sensitive to vaccine-elicited antibodies as compared to wild type (WT) Wuhan-1 bearing D614G. Serum neutralising titres against B.1.617.2 were lower in ChAdOx-1 versus BNT162b2 vaccinees. B.1.617.2 spike pseudotyped viruses exhibited compromised sensitivity to monoclonal antibodies against the receptor binding domain (RBD) and N-terminal domain (NTD). B.1.617.2 demonstrated higher replication efficiency in both airway organoid and human airway epithelial systems compared to B.1.1.7, associated with B.1.617.2 spike in a predominantly cleaved state compared to B.1.1.7. The B.1.617.2 spike protein was able to mediate highly efficient syncytium formation that was less sensitive to inhibition by neutralising antibody as compared to WT spike. Additionally we observed that B.1.617.2 had higher replication and spike mediated entry as compared to B.1.617.1, potentially explaining B.1.617.2 dominance. In an analysis of over 130 SARS-CoV-2 infected healthcare workers across three centres in India during a period of mixed lineage circulation, we observed reduced ChAdOx-1 vaccine effectiveness against B.1.617.2 relative to non-B.1.617.2, with the caveat of possible residual confounding. Compromised vaccine efficacy against the highly fit and immune evasive B.1.617.2 Delta variant warrants continued infection control measures in the post-vaccination era. India's first wave of SARS-CoV-2 infections in mid-2020 was relatively mild and was controlled by a nationwide lockdown. Since easing of restrictions, India has seen expansion in cases of COVID-19 since March

Our study highlights the growing problem of high antimicrobial consumption. The increasing prevalence of non-fermenters and the emergence of multidrug-resistant A. baumannii are associated with the consumption of carbapenems. The data cannot prove cause and effect.

The study evaluates the utility of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) Vitek MS for identification of microorganisms in the routine clinical microbiology laboratory. From May 2013 to April 2014, microbial isolates recovered from various clinical samples were identified by Vitek MS. In case of failure to identify by Vitek MS, the isolate was identified using the Vitek 2 system (bioMerieux, France) and serotyping wherever applicable or otherwise by nucleic acid-mediated methods. All the moulds were identified by Lactophenol blue mounts, and mycobacterial isolates were identified by molecular identification systems including AccuProbe (bioMerieux, France) or GenoType Mycobacterium CM (Hain Lifescience, Germany). Out of the 12,003 isolates, the Vitek MS gave a good overall ID at the genus and or species level up to 97.7% for bacterial isolates, 92.8% for yeasts and 80% for filamentous fungi. Of the 26 mycobacteria tested, only 42.3% could be identified using the Saramis RUO (Research Use Only) database. VITEK MS could not identify 34 of the 35 yeast isolates identified as C. haemulonii by Vitek 2. Subsequently, 17 of these isolates were identified as Candida auris (not present in the Vitek MS database) by 18S rRNA sequencing. Using these strains, an in-house superspectrum of C. auris was created in the VITEK MS database. Use of MALDI-TOF MS allows a rapid identification of aerobic bacteria and yeasts in clinical practice. However, improved sample extraction protocols and database upgrades with inclusion of locally representative strains is required, especially for moulds.

High frequencies of multidrug resistant organisms were observed in intensive care units which is a warning as to use the only few effective antimicrobials wisely to reduce selective pressure on sensitive strains.

MTBDRplus assay had good sensitivity and specificity with turn around time of less than 48 hours. It may be a useful tool for rapid detection of multidrug resistant tuberculosis at a tertiary care centre.

No abstract

PCR can play an important role in rapid and accurate diagnosis of extrapulmonary tuberculosis. IS6110 alone is an effective target in our part of the country.

Background & objectives:Multidrug-resistant tuberculosis (MDR-TB) is a public health problem of great significance in India. In the present study an attempt was made to analyse the progression of MDR-TB pattern during a course of 13 years (2000-2012) among the patient population at a tertiary care centre in New Delhi, India.Methods:Mycobacterial isolates obtained on Lowenstein-Jensen (L-J) medium/BacT/ALERT 3D were identified using AccuProbe molecular identification system, routine biochemical tests or GenoType Mycobacteria CM. Antimycobacterial susceptibility testing was performed using resistance ratio method on L-J medium (2000-2004) and one per cent proportion method on BacT/ALERT 3D system (2005-2012).Results:Of the total 14,849 samples subjected to mycobacterial culture, 6569 pulmonary and 8280 extrapulmonary, 2364 were detected positive for mycobacteria. The average percentage positivity rate was 15.9 per cent (18.9 and 13.6% in case of pulmonary and extrapulmonary samples, respectively). Our study revealed a significant increase (P<0.001) in multidrug resistance by 12 per cent (4.7% in 2000 to 19.8% in 2012). MDR-TB was more in case of pulmonary (28.2%) than extrapulmonary (11.6%) TB (P<0.001). Only 6.5 per cent (154) of mycobacterial isolates were non-tuberculous mycobacteria and rapid growers represented by Mycobacterium fortuitum and M. abscessus were the most commonly isolated species.Interpretation & conclusions:Increase in prevalence of MDR-TB by 12 per cent in the past 13 years is alarming. Policy modifications may have to be done to strengthen the existing TB control programmes to encourage contact tracing and culture and drug susceptibility testing for all smear positive pulmonary cases to ensure early and appropriate therapy.