Streptococcus suis is a leading cause of bacterial meningitis in South-East Asia, with frequent zoonotic transfer to humans associated with close contact with pigs. A small number of invasive lineages are responsible for endemic infection in the swine industry, causing considerable global economic losses. A lack of surveillance and a rising trend in clinical treatment failure has raised concerns of growing antimicrobial resistance (AMR) among invasive S. suis . Gene flow between healthy and disease isolates is poorly understood and, in this study, we sample and sequence a collection of isolates predominantly from healthy pigs in Chiang Mai province, Northern Thailand. Pangenome characterization identified extensive genetic diversity and frequent AMR carriage in isolates from healthy pigs. Multiple AMR genes were identified, conferring resistance to aminoglycosides, lincosamides, tetracycline and macrolides. All isolates were non-susceptible to three or more different antimicrobial classes, and 75 % of non-serotype 2 isolates were non-susceptible to six or more classes (compared to 37.5 % of serotype 2 isolates). AMR genes were found on integrative and conjugative elements previously observed in other species, suggesting a mobile gene pool that can be accessed by invasive disease isolates. This article contains data hosted by Microreact.

Tadee P, et al. J Vet Sci. 2023 Dec;25(1):e5. https://doi.org/10.4142/jvs.23189

Mastitis is a major infectious disease that causes significant economic losses in the dairy industry. Current control programs primarily rely on antimicrobials, contributing to the growing concerns of the resistance situation and drug residues in milk. This study aimed to identify the bacterial pathogens responsible for subclinical/clinical bovine mastitis, assess their antimicrobial resistance profiles, and evaluate the antimicrobial effects of Caesalpinia sappan in treating mastitis through both in vitro and in vivo studies. A total of 138 bacterial isolates, representing 40 species, were identified from 100 milk samples collected from dairy cows under the Maejo Cooperative Group in Chiang Mai, Thailand, between May 2021 and February 2022. The most prevalent species was Escherichia coli (10.87%), followed by Bacillus cereus (9.42%) and Staphylococcus sciuri (7.97%). The highest resistance rates were observed for penicillin (65.21%), followed by streptomycin and lincomycin (61.59%). Nine isolates resisted all 18 antimicrobials tested. The average minimum inhibitory concentration (MIC) of C. sappan against the identified pathogens ranged from 0.63 to 17.68 mg/mL, with the highest MIC observed against Pseudomonas luteola. In the animal experiment, treatment with a prototype of an intramammary infusion compound primarily formulated from C. sappan significantly reduced the total bacterial count and California Mastitis Test (CMT) scores (p < 0.01). These results suggest that C. sappan exhibits antimicrobial efficacy against various mastitis bacteria and could serve as a potential alternative treatment to control bovine mastitis in dairy cattle within the study region.

Bacterial respiratory disease is one of the major concerns in the modern pig industry. To address the limitations of culture-based methods, 16S rRNA sequencing was employed to characterize the pig lung microbiome to gain a better understanding of microbial physiology and their population genetics. A batch of 510 slaughtered pigs from a farm located in Lampang province, Thailand, was selected. Individual pig weight was recorded. A total of 24 lungs (10 normal and 14 pneumonic lungs) were sampled for gross lesion examination and lung microbial communities were investigated. Poor growth performance and weight uniformity were denoted in this batch. Several pathogenic bacteria were detected in both normal and pneumonic lungs. Microbial diversity was decreased in the pneumonic group. PCoA and NMDS analysis showed a clear separation between the groups. Stenotrophomonas spp. (42.12%) was the dominant genus identified in normal lungs, while Mycoplasma hyopneumoniae (71.97%) was the most abundant in pneumonic lungs, correlating with the commonly observed consolidation lesions. The slaughterhouse serves as a key checkpoint for gathering comprehensive information on pig respiratory health, and lung is representative of the lower respiratory tract for microbiomics. Monitoring of lung lesions should be implemented routinely to gain a better understanding of regional pig respiratory health.

Mastitis is a major infectious disease that causes significant economic losses in the dairy industry. Current control programs primarily rely on antibiotics, contributing to the growing concerns of antibiotic resistance and drug residues in milk. This study aimed to identify the bacterial pathogens responsible for bovine mastitis, assess their antibiotic resistance profiles, and evaluate the antimicrobial effects of Caesalpinia sappan in treating mastitis through both in vitro and in vivo studies. A total of 138 bacterial isolates representing 40 species were identified from 100 milk samples collected from dairy cows raised under the Maejo Cooperative Group, Chiang Mai, Thailand, between May 2021 and February 2022. The most prevalent species was Escherichia coli (10.87%), followed by Bacillus cereus (9.42%) and Staphylococcus sciuri (7.97%). The highest resistance rates were observed for penicillin (63.04%), followed by streptomycin (60.87%) and lincomycin (57.25%). Nine isolates resisted all 18 antibiotics tested. The minimum inhibitory concentration (MIC) of Caesalpinia sappan against the identified pathogens ranged from 0.63 to 17.68 mg/ml, with the highest MIC observed against Pseudomonas luteola. In the animal experiment, treatment with a prototype of intramammary infusion derived from Caesalpinia sappan with and adding Aloe vera significantly reduced the total bacterial count and California Mastitis Test (CMT) scores (p < 0.01). These results suggest that Caesalpinia sappan exhibit antimicrobial efficacy against various mastitis bacteria and could serve as a potential alternative treatment for managing bovine mastitis in dairy cattle within the study region.