Lakes and rivers are sources of livelihood, food and water in many parts of the world. Lakes provide natural resources and valuable ecosystem services. These aquatic ecosystems are also vulnerable to known and new environmental pollutants. Emerging water contaminants are now being studied including antibiotics because of the global phenomenon on antibiotic resistance. β-Lactam antibiotics are widely used in human and animal disease prevention or treatment. The emergence of antibiotic resistance is a public health threat when bacteria become more resistant and infections consequently increase requiring treatment using last resort drugs that are more expensive. This review summarizes the key findings on the occurrence, contamination sources, and determination of β-lactam antibiotics and β-lactam antibiotic resistant bacteria and genes in the Asian lake and river waters. The current methods in the analytical measurements of β-lactam antibiotics in water involving solid-phase extraction and liquid chromatography-mass spectrometry are discussed. Also described is the determination of antibiotic resistance genes which is primarily based on a polymerase chain reaction method. To date, β-lactam antibiotics in the Asian aquatic environments are reported in the ng/L concentrations. Studies on β-lactam resistant bacteria and resistance genes were mostly conducted in China. The occurrence of these emerging contaminants is largely uncharted because many aquatic systems in the Asian region remain to be studied. Comprehensive investigations encompassing the environmental behavior of β-lactam antibiotics, emergence of resistant bacteria, transfer of resistance genes to non-resistant bacteria, multiple antibiotic resistance, and effects on aquatic biota are needed particularly in rivers and lakes that are eventual sinks of these water contaminants.

The use of wastewater for rearing domestic animals is a common phenomenon in most of the developing countries like Pakistan that face a serious shortage of freshwater resources. However, most of the literature has only focused on the indirect effects of wastewater use on animal health or productivity, and literature on the direct effects of wastewater use is rare. Therefore, this study aims to investigate the direct and indirect effects of wastewater usage on the prevalence of animal diseases and animal health in Pakistan. The study is based on a household-level survey of 360 domestic water buffalo herds collected from 12 districts of Punjab Province, Pakistan. We tested the prevalence of the animal’s diseases, animal’s health, and wastewater-use preference with various econometric tools, such as the Poisson, negative binomial, and logistic regressions. The findings of the study show that the majority of the farmers use wastewater for buffalo bathing due to the shortage of freshwater resources. Results explore the prevalence of diseases such as clinical mastitis, tick infestation, and foot and mouth disease at the farm level significantly associated with buffalo bathing in the wastewater. Moreover, bathing in wastewater pre- and post-milking also plays a role in the occurrence of diseases. Particularly, if the buffalo’s access to wastewater for bathing is within 60 min after milking, the probability of the animals being exposed to mastitis is higher. Furthermore, on investigation, a number of factors are found, such as the distance to the water source, power shortage, groundwater availability, and the education of farmers that influence farmers’ behavior of letting their animals take a bath in wastewater. Moreover, the use of different preventive measures improves the animal’s health.

Intestinal microflora plays a key role in maintaining the homeostasis between immune and host health. Here, we reported the fluoride-induced changes of rectal structure and microflora in mice. The morphology of rectal tissue was observed by hematoxylin and eosin staining. The rectal development parameters (the thickness of mucosa, intestinal gland and muscle layer) were evaluated. The proliferation of rectal epithelial cells was evaluated via BrdU labeling. The distribution of goblet, glycoprotein and mast cell were evaluated by specific staining. Rectal microflora was detected using 16S rRNA high-throughput sequencing. The results showed that the rectal structure was seriously damaged and the proliferation of rectal epithelial cells was significantly inhibited by fluoride. The distribution of goblet cells, glycoprotein and mast cells decreased significantly after fluoride exposure. The relative richness of microfloras was changed after fluoride treatment, such as increased Bacteroidetes and decreased Firmicutes. In summary, this study indicated that excessive fluoride damages the intestinal structure, disturbs the intestinal micro-ecology and causes intestinal microflora disorder in mice. Findings mentioned in the present study enrich a new scope for elucidating fluoride toxicity from intestinal homeostasis.