Public health significance of coronaviruses carried by aquatic animals / 公共卫生与预防医学

This paper reviews the coronavirus species and post-infection symptoms of aquatic animals such as marine mammals, ferrets, fish, and waterfowl, analyzes the activity and transmission of coronaviruses in the aquatic environment, compares the homology of aquatic coronaviruses with SARS-CoV-2, and assesses the zoonotic risk. The results showed that aquatic animal coronaviruses were mainly α, γ, δ coronavirus and Alphaletovirus. SARS⁃CoV⁃2 is more similar to marine mammal coronavirus (51.90%-52.30%) and less similar to fish, mink, duck and goose coronavirus (43.30%-47.90%). The risk of transmission of coronaviruses carried by minks and marine mammals to humans is relatively greater, and from fish and waterfowl to humans is relatively small. By elaborating on the situation of coronavirus infection in aquatic animals, this paper is conducive to solving related issues such as the prevention and control of coronavirus epidemics, which is of great significance to ecosystems and public health.

Antibiotic resistance and virulence factors among Escherichia coli isolates from avian organic fertilizer / Resistência a antibióticos e fatores de virulência entre isolados de Escherichia coli provenientes de fertilizante orgânico aviário

ABSTRACT: Brazilian poultry industry generates large amounts of organic waste, such as chicken litter, which is often used in agriculture. Among the bacteria present in organic fertilizer are members of the Enterobacteriaceae family, such as Escherichia coli. The aim of this study was to analyze the profile of virulence factors and antimicrobial resistance of E. coli isolates from avian organic fertilizer. A total of 47 E. coli strains were tested through Polymerase chain reaction to detect virulence genes (hlyF, iss, ompT, iutA and iroN). Fourteen antimicrobials were used to test antimicrobial susceptibility in the strains. Genes characteristic of Avian Pathogenic E. coli (APEC) were reported among the strains, with the hlyF, iss and ompT genes being the most prevalent. The isolates showed high resistance (˃50%) to tetracycline, gentamicin, cefotaxime, nitrofurantoin, trimethoprim-sulfamethoxazole and ampicillin. Multidrug resistance was reported in a great number of strains (>70%). The results showed the presence of APEC cells with virulence genes and antimicrobial resistance after 15 days of the windrowing process in poultry houses, it means this process should be improved to eliminate these cells.

RESUMO: A indústria avícola brasileira gera grandes quantidades de resíduos orgânicos, como a cama de frango, utilizada frequentemente na agricultura. Entre as bactérias presentes neste fertilizante orgânico estão os membros da família Enterobacteriaceae, entre eles a Escherichia coli. O objetivo deste estudo foi analisar o perfil de fatores de virulência e resistência antimicrobiana de isolados de E. coli provenientes do fertilizante orgânico aviário. Um total de 47 cepas de E. coli foram testadas por meio da reação em cadeia da polimerase para detectar genes de virulência (hlyF, iss, ompT, iutA e iroN). Quatorze antimicrobianos foram utilizados para testar a susceptibilidade antimicrobiana nos isolados. Genes característicos de E. coli Patogênica Aviária (APEC) foram encontrados entre os isolados, sendo os genes hlyF, iss e ompT os mais prevalentes. Os isolados apresentaram alta resistência (˃50%) à tetraciclina, gentamicina, cefotaxima, nitrofurantoína, trimetoprima-sulfametoxazole e ampicilina. Múltipla resistência a drogas antimicrobianas foi encontrada em grande número de isolados (>70%). Os resultados obtidos mostraram a presença de células APEC portando genes de virulência e resistência a antimicrobianos após 15 dias de processo de empilhamento nas granjas, indicando que o processo necessita de um aperfeiçoamento para eliminar estas células.

Subtype Distribution of Blastocystis in Communities along the Chao Phraya River, Thailand

Blastocystis is a common zoonotic enteric protozoan that has been classified into 17 distinct subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distributions of Blastocystis in villagers living along the Chao Phraya River, Ayutthaya Province, Thailand, and to assess the risk of zoonotic infection. In total, 220 stool samples were collected, and DNA was extracted. PCR and sequencing were performed with primers targeting the small-subunit ribosomal RNA (SSU rRNA) genes. Blastocystis was present in 5.9% (13/220) of samples, and ST3 (5.0%; 11/220) was the predominant subtype, followed by ST2 (0.45%; 1/220) and ST6 (0.45%; 1/220). Phylogenetic trees were constructed with the maximum-likelihood method based on the Hasegawa–Kishino–Yano + G + I model, neighbor-joining, and maximum parsimony methods. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. All the sequences of the Blastocystis-positive samples (KU051524–KU051536) were closely related to those from animals (pig, cattle, and chicken), indicating a zoonotic risk. Therefore, the villagers require proper health education, especially regarding the prevention of parasitic infection, to improve their personal hygiene and community health. Further studies are required to investigate the Blastocystis STs in the animals living in these villages.

Subtype Distribution of Blastocystis in Thai-Myanmar Border, Thailand

Blastocystis sp. is a common zoonotic intestinal protozoa which has been classified into 17 subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distribution of Blastocystis in villagers living on the Thai-Myanmar border, where the risk of parasitic infection is high. A total of 207 stool samples were collected and DNA was extracted. PCR and sequencing using primers targeting small-subunit ribosomal RNA (SSU rRNA) gene were performed. The prevalence of Blastocystis infection was 37.2% (77/207). ST3 (19.8%; 41/207) was the predominant subtype, followed by ST1 (11.6%; 24/207), ST2 (5.3%; 11/207), and ST4 (0.5%; 1/207). A phylogenetic tree was reconstructed using the maximum likelihood (ML) method based on the Hasegawa-Kishino-Yano + G + I model. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. Some sequences of Blastocystis positive samples (TK18, 39, 46, 71, and 90) were closely related to animals (pig and cattle) indicating zoonotic risks. Therefore, proper health education in parasitic prevention for the villagers should be promoted to improve their personal hygiene. Further longitudinal studies are required to monitor the prevalence of parasitic infections after providing health education and to investigate Blastocystis ST in animals living in these villages.