Evaluation of immunogenicity post two doses of inactivated SARS-CoV-2 vaccine, Covaxin after six months.

We have evaluated the immunogenicity of two dose of Covaxin given at a one-month interval to two adult populations, i.e. COVID-19 naïve-vaccinated individuals (n = 118) and COVID-19 recovered individuals (n = 128) with the vaccination. The immune response in the study population were assessed at three follow-ups, namely at one month post first dose, one and six months after the second dose. The persistence of S1RBD IgG and neutralizing antibodies for six months post vaccination was observed at different time intervals. The enhanced immune response was observed in both the participant groups. The study emphasizes the need for a booster dose post six months of vaccination.

Molecular detection of virulence markers to identify diarrhoeagenic Escherichia coli isolated from Mula-Mutha river, Pune District, India.

In this study presence of virulence genes in multidrug resistant Escherichia coli isolated from Mula-Mutha river, Pune, India was undertaken. The objective was to understand whether the isolates were of diarrhoeagenic or of environmental origin. This was essential since the river flows through urban and rural parts of Pune and its water is used not only for industrial and agricultural purposes but also for domestic usage. One hundred and two multidrug E. coli isolates were selected from our previous study which detected genes coding for antibiotic resistance as well as identified integrons associated with multidrug resistance. Isolates were subjected to multiplex PCR to detect presence of virulence genes, set1A, set1B, sen astA, aggA, aafA, pet, stx1 and stx. Sequencing was performed to confirm the amplified PCR product. Seven of the 102 E. coli isolates showed gene set1A alone identifying them as Enteroaggregative E. coli. Thus, the findings revealed that majority of drug resistant E. coli were environmental in origin. The presence of antibiotic resistant genes, integrons in the environment as well as diarrhoeagenic E. coli isolates is a warning and calls for efficient public health measures to ensure that untreated sewage and industrial waste does not enter the Mula-Mutha river.

Seasonal prevalence of antibiotic-resistant bacteria in the river Mula-Mutha, India.

The river Mula-Mutha in Pune District, India, is linked to a number of major drinking water sources in villages situated along its banks. This study assessed the seasonal variations in bacteriological water quality along the Mula-Mutha river using Thermotolerant Faecal Coliforms (TFC) as indicator bacteria for faecal contamination as per the WHO standard guidelines for drinking water. Eight points were chosen based on a survey carried out focusing on different sources of contamination which may influence water quality. Based on the survey of antibiotics used to treat routine diseases and ailments in villages, ceftazidime and ciprofloxacin were selected to screen and enumerate antibiotic-resistant (AR) TFC. The water samples were collected and analyzed along the Mula-Mutha riverbank in three seasons. The highest TFC load was recorded during the monsoon at all eight sampling points. The percentages of ciprofloxacin-resistant TFC among the TFC isolated in post-monsoon, pre-monsoon and monsoon were 21%, 2.3%, and 64%, to those resistant to ceftazidime 9%, 0.5%, and 36% and to the combination 38%, 0.7%, and 43%, respectively. Downstream from Manjari, at Khamgaontek, antibiotic-resistant TFC were detected in all three seasons though the number isolated was less. Still further downstream at Walki, the numbers decreased considerably. The findings highlighted the heavy load of AR TFC detected in the river Mula-Mutha at points adjoining Pune City. This was probably due to the release of domestic and hospital wastes from the city into the river.

Antibiotic Resistance Characterization of Environmental E. coli Isolated from River Mula-Mutha, Pune District, India.

In the current study, ceftazidime- and ciprofloxacin-resistant—or dual drug-resistant (DDR)—E. coli were isolated from river Mula-Mutha, which flows through rural Pune district and Pune city. The DDR E. coli were further examined for antibiotic resistance to six additional antibiotics. The study also included detection of genes responsible for ceftazidime and ciprofloxacin resistance and vectors for horizontal gene transfer. Twenty-eight percent of the identified DDR E. coli were resistant to more than six antibiotics, with 12% being resistant to all eight antibiotics tested. Quinolone resistance was determined through the detection of qnrA, qnrB, qnrS and oqxA genes, whereas cephalosporin resistance was confirmed through detection of TEM, CTX-M-15, CTX-M-27 and SHV genes. Out of 219 DDR E. coli, 8.2% were qnrS positive and 0.4% were qnrB positive. Percentage of isolates positive for the TEM, CTX-M-15 and CTX-M-27 genes were 32%, 46% and 0.9%, respectively. None of the DDR E. coli tested carried the qnrA, SHV and oqxA genes. Percentage of DDR E. coli carrying Class 1 and 2 integrons (mobile genetic elements) were 47% and 8%, respectively. The results showed that antibiotic resistance genes (ARGs) and integrons were present in the E. coli isolated from the river at points adjoining and downstream of Pune city.