Wild birds have been postulated as sentinels, reservoirs, and potential spreaders of antibiotic resistance. Antibiotic-resistant bacteria have been isolated from a multitude of wild bird species. Several studies strongly indicate transmission of resistant bacteria from human rest products to wild birds. There is evidence suggesting that wild birds can spread resistant bacteria through migration and that resistant bacteria can be transmitted from birds to humans and vice versa. Through further studies of the spatial and temporal distribution of resistant bacteria in wild birds, we can better assess their role and thereby help to mitigate the increasing global problem of antibiotic resistance.

The agricultural food products industry in Bangladesh depends on utilizing antimicrobials indiscriminately as growth promoters and for controlling infectious diseases. Thus, there is always a risk of antimicrobial agent accumulation in food sources that originate from agricultural production. In the present study, we collected data from published articles between January, 2013 and December, 2019 on antimicrobial residues in human food sources such as meat, milk, eggs, and fishes. Liver contained the highest percentage of antimicrobial residues (74%; 95% CI: 59.66–85.37) against the in vitro enteric pathogen Escherichia coli in layer chickens. Similar results were demonstrated in liver (68%; 95% CI: 53.30–80.48) and kidney (66%, 95% CI: 51.23–78.79) of layer chickens against Bacillus cereus and Bacillus subtilis. Amongst all antibiotics, the highest concentrations of ciprofloxacin were detected in kidney (48.57%; 95% CI: 31.38–66.01), followed by liver (47.56; 95% CI: 40.88–54.30) of broiler chickens. Ciprofloxacin was also present in liver (46.15%; 95% CI: 33.70–58.96) of layer chickens. The percentage of ciprofloxacin in thigh and breast meat in broiler bird were 41.54% (95% CI: 34.54–48.79) and 37.95% (95% CI: 31.11–45.15) respectively. Enrofloxacin was the second most dominant antimicrobial agent and was present in the liver of both types of poultry (Broiler and Layer chickens: 41.54%; 95% CI: 29.44–54.4 and 437.33%; 95% CI: 30.99–44.01). The prevalence rates of enrofloxacin in thigh and breast meat of broiler chickens were 24.10% (95% CI: 18.28–30.73) and 20.51% (95% CI: 15.08–26.87), respectively. Tetracycline, a commonly used antibiotic in livestock, was present in the liver (49.23%; 95% CI: 36.60–61.93) of layer chickens. In case of aquaculture food products, the highest amount of amoxicillin (683.2 mg/kg) was detected in Tilapia fish (Oreochromis niloticus), followed by 584.4 mg/kg in climbing perch (Anabas testudineus) and 555.6 mg/kg in Rui fish (Labeo rohita). Among the five types of fishes, Rui fish (0.000515 mg/kg) contained the highest concentrations of chloramphenicol antibiotic residues. The presence of antimicrobial residues in meat, milk, egg, and fish is a serious public health threat due to the potential induction of antimicrobial resistance. It can negatively impact the food supply chain, especially with the current strain that it is already facing with the current COVID-19 pandemic. The findings of the present study highlight the ongoing risk of residual antimicrobial agents in food of animal origin in Bangladesh and countries with similar practices. This can draw the attention of public health officials to propose plans to mitigate or stop this practice.

The environment is an integral component of human and animal health. COVID-19 is a global health challenge in the twenty-first century. The emergence of SARS-CoV-2 in Wuhan, China in December 2019, and its spread to regional countries and nowadays affecting more than 210 countries worldwide represents the first pandemic in history to be caused by a coronavirus. The COVID-19 pandemic has huge impacts on most aspects of human activities, as well as on the economy and health care systems. Lock-downs, quarantines and border closures in the wake of the pandemic have led to reductions in air pollution through decreased travel and production. These positive environmental effects are likely mostly temporary, but may serve as an example that changes in our way of life can have prompt positive effects for the environment and demonstrate the usefulness of travel-reducing measures such as teleconferencing. Thus, acknowledging that COVID-19 is first and foremost a global disaster, the pandemic may inspire to future behavioral changes with positive environmental effects.

Oseltamivir (Tamiflu®) is the most widely used drug against influenza infections and is extensively stockpiled worldwide as part of pandemic preparedness plans. However, resistance is a growing problem and in 2008–2009, seasonal human influenza A/H1N1 virus strains in most parts of the world carried the mutation H274Y in the neuraminidase gene which causes resistance to the drug. The active metabolite of oseltamivir, oseltamivir carboxylate (OC), is poorly degraded in sewage treatment plants and surface water and has been detected in aquatic environments where the natural influenza reservoir, dabbling ducks, can be exposed to the substance. To assess if resistance can develop under these circumstances, we infected mallards with influenza A/H1N1 virus and exposed the birds to 80 ng/L, 1 µg/L and 80 µg/L of OC through their sole water source. By sequencing the neuraminidase gene from fecal samples, we found that H274Y occurred at 1 µg/L of OC and rapidly dominated the viral population at 80 µg/L. IC₅₀ for OC was increased from 2–4 nM in wild-type viruses to 400–700 nM in H274Y mutants as measured by a neuraminidase inhibition assay. This is consistent with the decrease in sensitivity to OC that has been noted among human clinical isolates carrying H274Y. Environmental OC levels have been measured to 58–293 ng/L during seasonal outbreaks and are expected to reach µg/L-levels during pandemics. Thus, resistance could be induced in influenza viruses circulating among wild ducks. As influenza viruses can cross species barriers, oseltamivir resistance could spread to human-adapted strains with pandemic potential disabling oseltamivir, a cornerstone in pandemic preparedness planning. We propose surveillance in wild birds as a measure to understand the resistance situation in nature and to monitor it over time. Strategies to lower environmental levels of OC include improved sewage treatment and, more importantly, a prudent use of antivirals.

Wild birds of the orders Anseriformes (mainly ducks, geese and swans) and Charadriiformes (mainly gulls, terns and waders) constitute the natural reservoir for low pathogenic avian influenza (LPAI) viruses. In Egypt, highly pathogenic avian influenza (HPAI) H5N1 and LPAI H9N2 viruses are endemic in domestic poultry, forming a threat to animal and human health and raising questions about the routes of introduction and mechanisms of persistence. Recently, HPAI H5N8 virus was also introduced into Egyptian domestic birds. Here we review the literature on the role of wild birds in the introduction and endemicity of avian influenza viruses in Egypt. Dabbling ducks in Egypt harbor an extensive LPAI virus diversity and may constitute the route of introduction for HPAI H5N1 and HPAI H5N8 viruses into Egypt through migration, however their role in the endemicity of HPAI H5N1, LPAI H9N2 and potentially other avian influenza virus (AIV) strains – by means of reassortment of viral genes – is less clear. Strengthened surveillance programs, in both domestic and wild birds, that include all LPAI virus subtypes and full genome sequencing are needed to better assess the wild–domestic bird interface and form a basis for evidence-based measures to limit and prevent AIV transmission between wild and domestic birds.

Disruptions in gut microbiome are implicated in cardiometabolic disorders and other health outcomes. Antibiotics are known gut microbiome disruptors, but their long-term consequences remain underexplored. Here we combined individual-level data from the Swedish Prescribed Drug Register with fecal metagenomes of 14,979 adults to examine the association between oral antibiotic use over 8 years and gut microbiome. In multivariable confounder-adjusted regression models, antibiotic use <1 year before fecal sampling was associated with the greatest reduction in species diversity, but significant associations were also observed for use 1–4 and 4–8 years earlier. Clindamycin, fluoroquinolones and flucloxacillin accounted for most of the associations with the abundance of individual species. Use of these antibiotics 4–8 years earlier was associated with altered abundance of 10–15% of the species studied; penicillin V, extended-spectrum penicillins and nitrofurantoin were associated with only a few species. Similar results were found comparing one antibiotic course 4–8 years before sampling versus none in the past 8 years. These findings indicate that antibiotics may have long-lasting consequences for the gut microbiome.