High prevalence of antibiotic resistance in pathogenic Escherichia coli from large- and small-scale poultry farms in Bangladesh

Antibiotic resistance in avian bacterial pathogens is a common problem in the Bangladesh poultry industry. The aim of the present study was to provide information on the present status of antibiotic resistance patterns in avian pathogenic Escherichia coli in Bangladesh. Of 279 dead or sick poultry of different ages, 101 pathogenic E coli strains isolated from broilers and layer hens with colibacillosis infections were screened to determine phenotypic expression of antimicrobial resistance against 13 antibiotics used in both veterinary and human medicine in Bangladesh. Of 101 pathogenic E. coli isolates, more than 55% were resistant to at least one or more of the tested compounds, and 36.6% of the isolates showed multiple-drug-resistant phenotypes. The most common resistances observed were against tetracycline (45.5%), trimethoprim-sulphamethoxazole (26.7%), nalidixic acid (25.7%), ampicillin (25.7%), and streptomycin (20.8%). Resistance to ciprofloxacin (12.9%), chlormaphenicol (8.9%), nitrofurantoin (2%), and gentamicin (2%) was also observed, and none of the isolates were resistant to tigecycline as well as extended spectrum beta-lactamase (ESBL) producers. One isolate was resistant to cefuroxime (1%), cefadroxil (1%), and mecillinam (1%) but was not an ESBL producer. Resistance rates, although significant in Bangladeshi isolates, were found to be lower than those reported for avian isolates from the Republic of Korea and clinical, avian, and environmental isolates from Bangladesh. The high level of antibiotic resistance in avian pathogens from Bangladesh is worrisome and indicates that widespread use of antibiotics as feed additives for growth promotion and disease prevention could have negative implications for human and animal health and the environment.     

The incidence of suspected white spot syndrome virus in semi‐intensive and extensive shrimp farms in Bangladesh: implications for management

The study was conducted to assess key factors influencing suspected white spot syndrome virus (WSSV) disease and associated shrimp production and economic performance in three contrasting black tiger shrimp (Penaeus monodon) culture technologies promoted by the United States Agency for International Development funded Shrimp Quality Support Project (SQSP) in Bangladesh. A total of 350 traditional, 315 Modified Traditional Technology1 (MTT1), 36 MTT2 and 88 Closed System Technology (CST) farmers from 10 sub‐districts in three districts of Khulna division were surveyed following random sampling at the end of the project. Binomial probit regression analysis revealed that smaller newly constructed ponds (known locally as gher) were less susceptible to WSSV, provided aquatic weeds were controlled using chemicals. Removal of sludge from ghers also had a positive effect, irrespective of technology and location. It was also shown that stocking of screened shrimp postlarvae (PL) does not guarantee protection against WSSV (t = 1.39, P > 0.05). Higher shrimp production was obtained by farmers practicing CST, followed by those operating MTTs and traditional technology respectively. Farmers who adopted CST also gained higher profitability followed by those operating MTT1, MTT2 and traditional technology.     

Allometric models for estimation of aboveground biomass of Gmelina arborea Roxb. in pulpwood plantations of Bangladesh

Gmelina arborea Roxb. is a fast-growing, deciduous tree species native to Bangladesh. It has been widely planted since 1992 for commercial production of pulpwood in hilly areas of Bangladesh. The purpose of this study was to derive well-fitting allometric models for estimation of aboveground biomass, and carbon and nutrient (nitrogen, phosphorus and potassium) stocks in G. arborea to ensure sustainable production and management of this species. Eight linear models with 64 regression equations were tested for estimation of aboveground biomass, carbon and nutrient stocks in different parts (leaves, branches, bark and stem) of the plant. The best-fitting allometric models were selected in accordance with various relevant statistical criteria.     

Potential for productivity improvements by implementing improved management practices in pond polyculture of Indian major carps in Bangladesh

The present study aims to assess the impact of improved management practices on productivity, profit, and consumption expenditure of carp farmers. This study was carried out in three of Bangladesh’s top carp-producing districts (administrative units). A total of 300 carp farmers were surveyed through face-to-face interviews. Data were analyzed with propensity score matching (PSM), inverse probability weighting (IPW), and inverse probability weighted regression adjustment (IPWRA). Improved management practices, such as improved fingerling variety, stocking density, feeding, pond water change, lime application, and proper drainage facilities, were considered to achieve the study’s objectives. Improved management practices were classified into simple, intermediate, and complex practices based on their complexity. Adopters of improved management practices achieved significantly higher productivity (248–299 kg ha^?1) based on various matching techniques compared to non-adopters. The impact of adoption on profitability and consumption expenditure was 22% and 34% on the basis of IPW. Due to higher productivity and profit, adopters were able to spend more on consumption. Findings also revealed that adopting simple management practice is insufficient to boost productivity and profit. More research is needed to develop and optimize the improved management practices as a package. Improvement in extension services is suggested to improve the adoption.