"One Health"--linking human, animal and environmental health

Prevalence and Molecular Characterization of Extended-Spectrum β-Lactamases and AmpC β-lactamase-Producing Enterobacteriaceae among Human, Cattle, and Poultry

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are a universal public health alarm frequently identified among humans, animals, and poultry. Livestock and poultry production are a possible source of multidrug-resistant microorganisms, including ESBL-producing Enterobacteriaceae, which confer antimicrobial resistance to different β-lactam antimicrobial agents. From January to May 2020, a cross-sectional study was carried out in three dairy cattle farms and four poultry farms in different districts of northern Egypt to assess the prevalence of ESBLs, AmpC beta-lactamase-producing E. coli and Klebsiella in livestock, poultry, and human contacts, and to investigate the genetic relatedness of the recovered isolates. In total, 140 samples were collected, including human fecal samples (n = 20) of workers with intimate livestock contact, cattle rectal swabs (n = 34), milk (n = 14), milking machine swabs (n = 8), rations (n = 2), and water (n = 2) from different cattle farms, as well as cloacal swabs (n = 45), rations (n = 5), water (n = 5) and litter (n = 5) from poultry farms. The specimens were investigated for ESBL-producing E. coli and Klebsiella using HiCrome ESBL media agar. The agar disk diffusion method characterized the isolated strains for their phenotypic antimicrobial susceptibility. The prevalence of ESBL-producing Enterobacteriaceae was 30.0%, 20.0%, and 25.0% in humans, cattle, and poultry, respectively. Further genotypic characterization was performed using conventional and multiplex PCR assays for the molecular identification of ESBL and AmpC genes. The majority of the ESBL-producing Enterobacteriaceae showed a multi-drug resistant phenotype. Additionally, bla_SHV was the predominant ESBL genotype (n = 31; 93.94%), and was mainly identified in humans (n = 6), cattle (n = 11), and poultry (14); its existence in various reservoirs is a concern, and highlights the necessity of the development of definite control strategies to limit the abuse of antimicrobial agents.

Prevalence and Genetic Relatedness of Extended Spectrum-β-Lactamase-Producing Escherichia coli Among Humans, Cattle, and Poultry in Pakistan

Objective: To determine the prevalence and genetic relatedness of bla_CTX-M-type extended spectrum-β-lactamase (ESBL)-producing Escherichia coli at the human-animal interface in Pakistan. Materials and Methods: A total of 150 human, cattle, and poultry fecal samples (50 each) were screened for ESBL-producing E. coli using ESBL CHROMagar^®. Bacterial species confirmation as well as determination of minimum inhibitory concentrations (μg/mL) to different antibiotics was performed using the automated VITEK^®-2 compact system. Phenotypic confirmation of ESBL production was performed according to the Clinical Laboratory Standards Institute (CLSI) guidelines. Genetic analysis of bla_CTX-M was carried out by PCR and DNA sequencing. Plasmids and clonal similarity of the E. coli strains were determined by PCR-based replicon typing and pulsed-field gel electrophoresis (PFGE), respectively. Results: Of 150 samples, 29 (19.3%) ESBL-producing E. coli were recovered, and majority of them originated from human (n = 16; 55%), followed by cattle (n = 9; 31%) and poultry (n = 4; 13.7%). bla_CTX-M-15 was predominant ESBL genotype (n = 25; 86.2%), mainly identified from human (n = 15) and cattle (n = 9). This is also the first report of the occurrence of CTX-M-15 and CTX-M-55 in cattle and poultry E. coli isolates of Pakistan, respectively. The majority of the ESBL-producing E. coli (96.5%) showed a multidrug resistance phenotype. All isolates carried IncFII or IncFIA plasmids, and the phylogroup B1 was dominant (44.8%) followed by phylogroups A (31%), D (17.2%), and B2 (6.8%). PFGE revealed that isolates from different hosts were genetically unrelated. Conclusion: Presence of CTX-M-15-type ESBL-producing E. coli in different reservoirs is alarming and has the potential to impact both veterinary and human therapeutic treatment options.

Urbanization and health in China, thinking at the national, local and individual levels

BACKGROUND

China has the biggest population in the world, and has been experiencing the largest migration in history, and its rapid urbanization has profound and lasting impacts on local and national public health. Under these conditions, a systems understanding on the correlation among urbanization, environmental change and public health and to devise solutions at national, local and individual levels are in urgent need.

METHODS

In this paper, we provide a comprehensive review of recent studies which have examined the relationship between urbanization, urban environmental changes and human health in China. Based on the review, coupled with a systems understanding, we summarize the challenges and opportunities for promoting the health and wellbeing of the whole nation at national, local, and individual levels.

RESULTS

Urbanization and urban expansion result in urban environmental changes, as well as residents' lifestyle change, which can lead independently and synergistically to human health problems. China has undergone an epidemiological transition, shifting from infectious to chronic diseases in a much shorter time frame than many other countries. Environmental risk factors, particularly air and water pollution, are a major contributing source of morbidity and mortality in China. Furthermore, aging population, food support system, and disparity of public service between the migrant worker and local residents are important contributions to China's urban health.

CONCLUSIONS

At the national level, the central government could improve current environmental policies, food safety laws, and make adjustments to the health care system and to demographic policy. At the local level, local government could incorporate healthy life considerations in urban planning procedures, make improvements to the local food supply, and enforce environmental monitoring and management. At the individual level, urban residents can be exposed to education regarding health behaviour choices while being encouraged to take responsibility for their health and to participate in environmental monitoring and management.

Fecal Indicator and Pathogenic Bacteria and Their Antibiotic Resistance in Alluvial Groundwater of an Irrigated Agricultural Region with Dairies

Surveys of microbiological groundwater quality were conducted in a region with intensive animal agriculture in California, USA. The survey included monitoring and domestic wells in eight concentrated animal feeding operations (CAFOs) and 200 small (domestic and community supply district) supply wells across the region. was not detected in groundwater, whereas O157:H7 and were each detected in 2 of 190 CAFO monitoring well samples. Nonpathogenic generic and spp. were detected in 24.2% (46/190) and 97.4% (185/190) groundwater samples from CAFO monitoring wells and in 4.2% (1/24) and 87.5% (21/24) of CAFO domestic wells, respectively. Concentrations of both generic and spp. were significantly associated with well depth, season, and the type of adjacent land use in the CAFO. No pathogenic bacteria were detected in groundwater from 200 small supply wells in the extended survey. However, 4.5 to 10.3% groundwater samples were positive for generic and . Concentrations of generic were not significantly associated with any factors, but concentrations of were significantly associated with proximity to CAFOs, seasons, and concentrations of potassium in water. Among a subset of and isolates from both surveys, the majority of (63.6%) and (86.1%) isolates exhibited resistance to multiple (≥3) antibiotics. Findings confirm significant microbial and antibiotic resistance loading to CAFO groundwater. Results also demonstrate significant attenuative capacity of the unconfined alluvial aquifer system with respect to microbial transport.