Chromosomal and plasmid localization of ileS2 in high-level mupirocin-resistant Staphylococcus pseudintermedius and Staphylococcus aureus isolated from canine and feline origins.

OBJECTIVES: To characterize the mobile genetic elements and genetic localization of ileS2 in high-level mupirocin-resistant (Hi-MupR) methicillin-resistant Staphylococcus pseudintermedius (MRSP) and MRSA isolates recovered from canine and feline clinical samples. METHODS: The identification of bacterial species and presence of mecA and ileS2 genes in MRSP and MRSA isolates were performed using MALDI-TOF MS and PCR, respectively. Antimicrobial resistance (AMR) phenotypes were determined by broth microdilution assays. The genome characteristics, ileS2-containing elements and staphylococcal cassette chromosome mec (SCCmec) were illustrated using complete circular genomes obtained from hybrid assembly of Illumina short-reads and Oxford Nanopore Technologies long-reads. These were analysed through phylogenetic and bioinformatics approaches. RESULTS: A total of 18 MRSP clinical isolates and four MRSA clinical isolates exhibited the Hi-MupR phenotype and carried multiple AMR genes, including mecA and ileS2 genes. MRSP ST182-SCCmec V (n = 6) and ST282-ΨSCCmec57395-t10 (n = 4) contained the ileS2 transposable unit associated with IS257 on the chromosome. Three MRSA ST398-SCCmec V-t034/t4652 isolates carried ∼42 kb pSK41-like ileS2 plasmids, whereas similar ileS2 plasmids lacking tra genes were found in MRSP ST282-ΨSCCmec57395-t72/t21 isolates. Furthermore, a new group of ileS2 plasmids, carried by MRSP ST45-ΨSCCmec57395, ST433-ΨSCCmecKW21-t05 and ST2165-SCCmec IV-t06, and by one MRSA ST398-SCCmec V-t034 strain, shared the plasmid backbone with the cfr/fexA-carrying plasmid pM084526_1 in MRSA ST398. CONCLUSIONS: This study provides the first evidence of ileS2 integration into the S. pseudintermedius chromosome, which is a rare occurrence in staphylococcal species, and plasmids played a pivotal role in dissemination of ileS2 in both staphylococcal species.

Multidrug-resistant Escherichia coli causing canine pyometra and urinary tract infections are genetically related but distinct from those causing prostatic abscesses.

Despite extensive characterisation of uropathogenic Escherichia coli (UPEC) causing urinary tract infections (UTIs), the genetic background of non-urinary extraintestinal pathogenic E. coli (ExPEC) in companion animals remains inadequately understood. In this study, we characterised virulence traits of 104 E. coli isolated from canine pyometra (n = 61) and prostatic abscesses (PAs) (n = 38), and bloodstream infections (BSIs) in dogs (n = 2), and cats (n = 3). A stronger association with UPEC of pyometra strains in comparison to PA strains was revealed. Notably, 44 isolates exhibited resistance to third-generation cephalosporins and/or fluoroquinolones, 15 were extended-spectrum ß-lactamase-producers. Twelve multidrug-resistant (MDR) strains, isolated from pyometra (n = 4), PAs (n = 5), and BSIs (n = 3), along with 7 previously characterised UPEC strains from dogs and cats, were sequenced. Genomic characteristics revealed that MDR E. coli associated with UTIs, pyometra, and BSIs belonged to international high-risk E. coli clones, including sequence type (ST) 38, ST131, ST617, ST648, and ST1193. However, PA strains belonged to distinct lineages, including ST12, ST44, ST457, ST744, and ST13037. The coreSNPs, cgMLST, and pan-genome illustrated intra-clonal variations within the same ST from different sources. The high-risk ST131 and ST1193 (phylogroup B2) contained high numbers of ExPEC virulence genes on pathogenicity islands, predominating in pyometra and UTI. Hybrid MDR/virulence IncF multi-replicon plasmids, containing aerobactin genes, were commonly found in non-B2 phylogroups from all sources. These findings offer genomic insights into non-urinary ExPEC, highlighting its potential for invasive infections in pets beyond UTIs, particularly with regards to high-risk global clones.

16S rRNA amplicon sequencing of seawater microbiota from Rayong Province, Thailand, affected by oil spills.

We reported on microbial communities isolated from 18 seawater samples affected by oil spills in Rayong province, Thailand, using the V3-V4 region of 16S rRNA gene sequencing.

Masculinization of Red Tilapia (Oreochromis spp.) Using 17α-Methyltestosterone-Loaded Alkyl Polyglucosides Integrated into Nanostructured Lipid Carriers.

The aim of the present study was to optimize a masculinization platform for the production of all-male red tilapia fry by oral administration of 30 and 60 ppm of MT and alkyl polyglucoside nanostructured lipid carriers (APG-NLC) loaded with MT, respectively, for 14 and 21 days. The characterization, encapsulation efficiency and release kinetics of MT in lipid-based nanoparticles were assessed in vitro. The results showed that the MT-loaded nanoparticles were spherical, ranging from 80 to 125 nm in size, and had a negative charge with a narrow particle distribution. The APG-NLC loaded with MT provided higher physical stability and encapsulation efficacy than the NLC. The release rate constants of MT from MT-NLC and MT-APG-NLC were higher than those of free MT, which is insoluble in aqueous media. There was no significant difference in survival between the fish administered MT or the those fed orally with MT-APG-NLC fish. According to the logistic regression analysis, the sex reversal efficacy of MT-APG-NLC (30 ppm) and MT (60 ppm), resulted in significantly higher numbers of males after 21 days of treatment compared with the controls. The production cost of MT-APG-NLC (30 ppm) after 21 days of treatment was reduced by 32.9% compared with the conventional MT treatment group (60 ppm). In all the treatments, the length-weight relationship (LWR) showed negatively allomeric growth behavior (b < 3), with a relative condition factor (Kn) of more than 1. Therefore, MT-APG-NLC (30 ppm) would seem to be a promising, cost-effective way to reduce the dose of MT used for the masculinization of farmed red tilapia.

Genetic characterization of hypervirulent Klebsiella pneumoniae responsible for acute death in captive marmosets.

Klebsiella pneumoniae is a Gram-negative bacterium implicated as the causative pathogen in several medical health issues with different strains causing different pathologies including pneumonia, bloodstream infections, meningitis and infections from wounds or surgery. In this study, four captive African marmosets housed in Thailand were found dead. Necropsy and histology revealed congestion of hearts, kidneys and adrenal glands. Twenty-four bacterial isolates were obtained from these four animals with all isolates yielding identical phenotypes indicative of K. pneumoniae based on classical identification schema. All the isolates show the susceptibility to amikacin, cephalexin, doxycycline, gentamicin, and enrofloxacin with intermediate susceptibility to amoxycillin/clavulanic acid. One isolate (20P167W) was chosen for genome analysis and determined to belong to sequence type 65 (ST65). The genome of 20P167W possessed multiple virulence genes including mrk gene cluster and iro and iuc gene cluster (salmochelin and aerobactin, respectively) as well as multiple antibiotic resistance genes including bla SHV-67, bla SHV-11, oqxA, oqxB, and fosA genes resembling those found in human isolates; this isolate has a close genetic relationship with isolates from humans in Ireland, but not from Thailand and California sea lions. Phylogenetic studies using SNP show that there was no relation between genetic and geographic distributions of all known strains typing ST65, suggesting that ST65 strains may spread worldwide through multiple international transmission events rather than by local expansions in humans and/or animals. We also predict that K. pneumoniae ST65 has an ability to acquire genetic mobile element from other bacteria, which would allow Klebsiella to become an even greater public health concern.

Draft Genome Sequences of Aeromonas schubertii Strains Isolated from Asian Seabass from Thailand.

Aeromonas schubertii is a Gram-negative, rod-shaped bacterium. It is a rare species that has been reported in humans and aquatic animals. Here, we report the genome sequences of A. schubertii strains isolated from two mass mortality events in central Thailand that were associated with aquaculture of Asian seabass.

Draft Whole-Genome Sequence of a Klebsiella pneumoniae Strain Isolated from a Marmoset in Thailand.

Klebsiella pneumoniae is a Gram-negative bacterium that can cause infection in various kinds of animals and humans. Here, we report the genome sequence of K. pneumoniae isolated from a captive marmoset in Thailand.

Draft Whole-Genome Sequences of Five Klebsiella pneumoniae Isolates from the Subantarctic Islands of New Zealand.

Klebsiella pneumoniae is a Gram-negative bacterium that can be found in the environment, as well as on mucosal surfaces of humans and animals. Here, we report the genome sequence of five K. pneumoniae isolates from substrate samples and bird feces collected in the Subantarctic Islands of New Zealand.

Draft Whole-Genome Sequences of Seven Isolates of Klebsiella pneumoniae from New Zealand Sea Lions.

Klebsiella pneumoniae is a Gram-negative bacterium that may cause infection in a broad range of hosts. We report here the genome sequences of seven K. pneumoniae isolates from New Zealand sea lions.

The study on the candidate probiotic properties of encapsulated yeast, Saccharomyces cerevisiae JCM 7255, in Nile Tilapia (Oreochromis niloticus).

Saccharomyces cerevisiae JCM 7255 was tested as a probiotic candidate in tilapia after encapsulating and freeze drying. Viability and morphology during storage and during transit through simulated gut and bile conditions were determined. Growth performance, anti-streptococcal activity and gut mucosal immune parameters were also tested. The viability of encapsulated yeasts was significantly high in simulated gastric and bile conditions and remained high after storage at room temperature for 14 days. The morphology of free S. cerevisiae revealed rough, bumpy, ruptured surface during incubation in gut and bile conditions. Agar spot anti-streptococcal activity showed inhibition of 20 out of 30 strains of Streptococcus agalactiae. Supplementation improved the intestinal structure and growth performance in tilapias. Intraepithelial lymphocytes in the proximal intestine were significantly observed. Lower cumulative mortality after the oral streptococcal challenge was also seen. The results suggest that encapsulated S. cerevisiae JCM 2755 could be a potential probiotic strain in tilapia culture.