Escherichia coli is not a suitable fecal indicator to assess water fecal contamination by otters

First Insights on Resistance and Virulence Potential of Escherichia coli from Captive Birds of Prey in Portugal

Captive birds of prey are often used for pest control in urban areas, while also participating in falconry exhibitions. Traveling across the country, these birds may represent a public health concern as they can host pathogenic and zoonotic agents and share the same environment as humans and synanthropic species. In this work, Escherichia coli from the cloacal samples of 27 captive birds of prey were characterized to determine their pathogenic potential. Isolates were clustered through ERIC-PCR fingerprinting, and the phylogenetic groups were assessed using a quadruplex PCR method. Their virulence and resistance profile against nine antibiotics were determined, as well as the isolates' ability to produce extended-spectrum β-lactamases (ESBLs). The 84 original isolates were grouped into 33 clonal types, and it was observed that more than half of the studied isolates belonged to groups D and B2. Most isolates presented gelatinase activity (88%), almost half were able to produce biofilm (45%), and some were able to produce α-hemolysin (18%). The isolates presented high resistance rates towards piperacillin (42%), tetracycline (33%), and doxycycline (30%), and 6% of the isolates were able to produce ESBLs. The results confirm the importance of these birds as reservoirs of virulence and resistance determinants that can be disseminated between wildlife and humans, stressing the need for more studies focusing on these animals.

Implications of Escherichia coli community diversity in free-ranging Australian pinniped pups

Escherichia coli is a widely studied bacterium, commonly used as an indicator of faecal contamination. Investigations into the structure and diversity of E. coli in free-ranging wildlife species has been limited. The objective of this study was to characterise intra-individual and inter-species E. coli phylotype and B2 sub-type diversity in free-ranging Australian pinniped pups, to determine whether a single E. coli colony is representative of the phylotype and B2 sub-type diversity in these hosts. Faecal samples were collected from free-ranging Australian fur seal (Arctocephalus pusillus doriferus), Australian sea lion (Neophoca cinerea) and long-nosed fur seal (Arctocephalus forsteri) pups from three breeding colonies between 2018 and 2021. Faecal swabs from thirty randomly selected pups (n = 10 from each species) were cultured and ten E. coli colonies were selected from each culture based on morphology and separation between colonies on agar plates. Molecular screening techniques were utilised to assign isolates to phylotypes and B2 sub-types. There was no significant difference (p > 0.05) in either intra-individual or inter-species E. coli phylotype and B2 sub-type diversity. The B2 phylotype was the most dominant, with 78% of isolates (n = 234) assigned to this phylotype. Host factors (species, weight [kg] and standard length [cm]) did not significantly affect phylotype diversity. The absence of intra-individual and inter-species differences in E. coli diversity at a phylotype level suggests that a single E. coli colony could be used as an indicator of overall diversity of E. coli at a phylotype level in A. p. doriferus, N. cinerea and A. forsteri pups. These findings can be used to simplify and improve the efficiency of sampling protocols for ongoing monitoring of human-associated E. coli phylotypes in free-ranging pinniped populations.

Evaluation of Water Quality of Buritis Lake

The implementation of natural parks in cities is a current and controversial theme. Therefore, in Lake Buritis, which is a leisure area for the population of the city of Goiatuba, Goiás, Brazil, the quality of the water was analyzed, carrying out quantitative tests of the water samples at six different points between the source and the outlet of the lake that flows into the stream, Chico À Toa. Physical–chemical tests (turbidity, pH, alkalinity, electrical conductivity, color, nitrate and hardness parameters), microbiological tests for species identification, analysis of the antimicrobial susceptibility profile, metals analysis and Allium cepa test, were performed. The total coliforms number in water samples was higher than the maximum value established by Brazilian legislation, demonstrating high fecal contamination during the spring in samples from an artesian well. The bacterial diversity found was large and there were many pathogenic bacteria. The A. cepa test demonstrated a cytotoxic potential for water from the source and outlet of Buritis Lake. Statistical tests were applied to verify existing correlations between parameters. Among the analyzed data, the highest correlation was between the color and turbidity parameters and the grouping between the metals (lead, iron, cadmium and magnesium).