Bioaccumulation of polystyrene microplastics and changes in antioxidant and AChE pattern in a freshwater snail (Filopaludina bengalensis) from river Ganga.

Microplastic pollution is a leading global problem affecting terrestrial and marine aquatic ecosystems. Due to the stagnant nature of microplastics, the toxic effect of microplastics is more pronounced to benthic organisms than the surface feeder. Hence, the present study effort was to study the microplastic bioaccumulation pattern and changes in the enzymatic and nonenzymatic antioxidant and AChE pattern of freshwater snail Filopaludina bengalensis, which were subjected to 0.5 ppm to 5 ppm levels of polystyrene microsphere (∼ 30 µm) for 27 days. The study showed that microplastics were easily accumulated in the test organism in a dose and time-dependent manner, amounting to 82 ± 6.02 particles /individuals at a 5 ppm dose on the 27th day. However, no mortality was observed at the test microplastic dosages. The enzymatic antioxidant profile (SOD and catalase) showed limited variability and remained stable with increased duration and microplastic dose. However, the nonenzymatic antioxidant profile showed distinct variability with the complete seizing of the DPPH activity on the 27th day at 5 ppm microplastic dose and a gradual decrease of ABTS and FRAP activity at all the dose ranges. Even the AChE activity decreased with higher exposure concentrations. The present study for the first time shows the direct impact of microplastics on a freshwater snail widely available in the Indian subcontinent, indicating the role of microplastic pollution will create havoc in the Ganga river eco-biosystem in the long run.

Phytoplankton diversity in wastewater impacted Indian Ramsar site: a study from East Kolkata Wetland.

A seasonal study was undertaken to understand the influence of wastewater on phytoplankton distribution in a water body of East Kolkata Wetland (EKW), a designated Ramsar site in Kolkata, West Bengal, India. A total of 19 different genera of phytoplankton belonging to 5 phyla were recorded. Among all the groups, Chlorophyceae was found to be dominated by 8 genera followed by Bacillariophycaeae (4 genera), Cyanophyceae (4 genera), Euglenophyceae (2 genera), and Zygnematophyceae (1 genus). Seasonal variability showed maximum dominance of phytoplankton during post-monsoon and least during pre-monsoon months. Shannon-Wiener diversity (H') indices indicated Bacillariophyceae to be most species rich (1.059) while the most dominant group (D) was observed to be Chlorophyceae (0.507). Assessment of Palmer algal pollution index (PI) revealed the water body is impacted by high organic pollution during monsoon (22) compared to the pre-monsoon (19) and post-monsoon seasons (15). The results of canonical correspondence analysis (CCA) indicated water temperature, alkalinity, total dissolved solids, dissolved oxygen, and electrical conductivity as the major influencing parameters for growth and distribution of the phytoplankton in the water body. Therefore, it can be stated that hydrological alteration of a water body fed with wastewater plays a significant role in regulating the plankton density, richness, and diversity.

Microbiome analysis reveals potential for modulation of gut microbiota through polysaccharide-based prebiotic feeding in Oreochromis niloticus (Linnaeus, 1758).

Characterization and functional profiling of the gut microbiota are essential for guiding nutritional interventions in fish and achieving favorable host-microbe interactions. Thus, we conducted a 30 days study to explore and document the gut microbial community of O. niloticus, as well as to evaluate the effects of a polysaccharide-based prebiotics with 0.5% and 0.75% Aloe vera extract on the gut microbiome through genomic analysis. The V3-V4 region of 16S rRNA was amplified and sequenced using Illumina HiSeq 2500, resulting in 1,000,199 reads for operational taxonomic unit (OTU) identification. Out of 8,894 OTUs, 1,181 were selected for further analysis. Our results revealed that Planctomycetes, Firmicutes, Proteobacteria, Verrucomicrobia, Actinobacteria, and Fusobacteria were the dominant phyla in both control and treatment samples. Higher doses of prebiotics were found to improve Planctomycetes and Firmicutes while decreasing Proteobacteria and Verrucomicrobia. We observed increasing trends in the abundance of Bacilli, Bacillaceae, and Bacillus bacteria at the class, family, and genus levels, respectively, in a dose-dependent manner. These findings were consistent with the conventional colony count data, which showed a higher prevalence of Bacillus in prebiotic-supplemented groups. Moreover, predicted functional analysis using PICRUSt indicated a dose-dependent upregulation in glycolysis V, superpathway of glycol metabolism and degradation, glucose and xylose degradation, glycolysis II, and sulfoglycolysis pathways. Most of the energy, protein, and amino acid synthesis pathways were upregulated only at lower doses of prebiotic treatment. Our findings suggest that the gut microbiome of O. niloticus can be optimized through nutritional interventions with plant-based polysaccharides for improved growth performance in commercial fish.

Rationality of Prescriptions by Rational Use of Medicine Consensus Approach in Common Respiratory and Gastrointestinal Infections: An Outpatient Department Based Cross-Sectional Study from India.

BACKGROUND: Drug utilisation studies are relevant for the analysis of prescription rationality and are pertinent in today's context of the increasing burden of antimicrobial resistance. Prescriptions for patients with diarrhoea or Acute Respiratory Infection (ARI) have been analysed in this study to understand the prescription pattern among various categories of prescribers in two tertiary care centers. METHODS: This cross-sectional study was conducted from August 2019 to December 2020 in the medicine and pediatrics outpatient departments of two government teaching hospitals in West Bengal, India. A total of 630 prescriptions were evaluated against WHO standards. Prescriptions were assessed by a 'Rational Use of Medicine Consensus committee' approach. RESULTS: The Fixed Dose Combination (FDC) was used in half of the patients (51%). Both the generic prescription (23.3%) and adherence to hospital formulary rates (36.5%) were low. The antibiotics prescription rate was high (57%), and it was higher for diarrhoea than ARI. Deviations from the standard treatment guidelines were found in 98.9% of prescriptions. Deviations were commonly found with prescriptions written by the junior doctors (99.6%). CONCLUSION: Irrational prescribing patterns prevail in tertiary care centers and indicate the necessity of awareness generation and capacity building among prescribers regarding AMR and its unseen consequences.

Co-Prevalence of Virulence and Pathogenic Potential in Multiple Antibiotic Resistant Aeromonas spp. from Diseased Fishes with In Silico Insight on the Virulent Protein Network.

Aeromonas species exhibit widespread presence in food, poultry, and aquaculture. They are major multi-drug-resistant fish pathogens. This study aims to identify Aeromonas species harbouring virulence genes aerolysin, flagellin, and lipase from diseased fishes of Assam wetlands with association with antibiotic resistance and in vivo pathogenicity. One hundred and thirty-four Aeromonas strains were isolated and thirty representative species identified using genus-specific 16S rRNA gene amplification. A. veronii was most prevalent (53.7%) followed by A. hydrophila (40.2%), A. caviae (4.47%), and A. dhakensis (1.49%). Ninety percent (90%) of strains harboured at least one of the studied virulence genes: aerA (73.3%), lip (46.6%), and flaA (26.6%). The highest multiple antibiotic resistance (MAR) index 0.8 corresponded to A. hydrophila DBTNE1 (MZ723069), containing all the studied genes. The lowest LD50 values (1.6 × 106 CFU/fish) corresponded to isolates having both aerA and lip. ß-lactams showed utmost resistance and lowest for aminoglycosides. There was a significant (p < 0.05) Pearson chi-square test of association between the occurrence of virulence and antibiotic resistance. The in silico protein−protein interaction revealed important drug targets, such as σ28 transcription factor, aminoacyl-tRNA synthetase, and diacylglycerol kinase, with significant (p < 0.05) enrichment. This study suggests that fish-isolate Aeromonas strains represent potential threat to aquaculture with subsequent risk of transferring antibiotic resistance to human pathogens.

Accumulation of lead by free and immobilized cyanobacteria with special reference to accumulation factor and recovery.

Lead accumulation by free and immobilized cyanobacteria, Lyngbya majuscula and Spirulina subsalsa was studied. Exponentially growing biomass was exposed to 1-20mg L(-1) of Pb(II) solution at pH 6, 7 and 8 for time periods ranging from 10 min to 48 h. L. majuscula accumulated 10 times more Pb (13.5 mg g(-1)) than S. subsalsa (1.32 mg g(-1)) at pH 6 within 3h of exposure to 20mg L(-1) Pb(II) solution and 76% of the Pb could be recovered using 0.1M EDTA. This chelator (2 µM) did not influence Pb accumulation whereas 100 µM citrate increased that of S. subsalsa 6- to 8-fold. L. majuscula filaments enmeshed in a glass wool packed in a column removed 95.8% of the Pb from a 5mg L(-1) Pb solution compared to free and dead biomass which removed 64 and 33.6% Pb respectively. A 92.5% recovery of accumulated Pb from the immobilized biomass suggests that repeated absorption-desorption is possible.

Bacterial incidence and antibiotic sensitivity pattern in moderate and severe infections in hospitalised patients.

Infectious diseases are among the leading causes of death and sometimes curable. Bacteria are the most common aetiology in hospitalised patients. Objectives of this study were to evaluate the incidence of bacterial infections and their pattern of susceptibility to antibiotics in moderate and severe infections in hospitalised patients. The study was performed in the apical teaching hospital of West Bengal in the first half of 2005. Patients admitted in medical wards and medical ICU, suffering from moderate and severe infections having APACHE-II score > 5 were studied. Clinical evaluation, routine and specific investigations were done in each case. Microbiological samplings were tried on day 1, after completion of antibiotic therapy and in between as required. Aerobic BACTEC bacterial culture and sensitivity tests were done. Pending initial culture and sensitivity report empiric antibiotic therapy was started, which was modified on getting the culture and sensitivity report. Outcome was observed as no response, cured, resolved, inconclusive, died and left against medical advice. Out of 40 patients total number of samples were 54 and that of sites of infections were 48. Primary site could not be detected in 11 infections (22.9%). Commonest form was urinary tract infection and abdominal infection in community acquired infection (n=18) and pneumonia in hospital acquired infection (n = 15). Culture was positive in 33 (61.11%), Gram-negative infection was more common in general, but incidence of Gram-positive infection was also quite high and Gram-positive infection was more common in community acquired infection. In general S aureus was most common bacteria -8 (24.24%). In community acquired infection S aureus 4 (22.22%) predominated followed by E coli and in hospital acquired infection S aureus -4 (26.66%) followed by E coli and P aeruginosa. Incidence of methicillin resistant Staph aureus was low. But it constituted 50% of S aureus. No methicillin resistant Staph aureus was found in community acquired infection. Two isolates of vancomycin intermediate sensitive Staph aureus were observed. Methicillin resistant Staph aureus showed maximum sensitivity to linezolid (100%) and all methicillin resistant Staph aureus but one vancomycin intermediate sensitive Staph aureus were sensitive to vancomycin. Coagulase negative Staph aureus were all sensitive to vancomycin and linezolid. Gram-negatives were mostly resistant to aminoglycosides and P aeruginosa were all sensitive to aztreonam. Single strain of S typhi as isolated was resistant to ceftriaxone and ciprofloxacin. P miribalis, P aeruginosa and coagulase negative Staph aureus were notoriously multidrug resistant; 82.5% of cases responded to treatment of which 35% were cured microbiologically. Gram-negative infection was more common overall, but incidence of Gram-positive infection was also very high. Gram-negative infections were responsible for more severe infections and case fatality. Multidrug resistant Gram-positive infections are rising.