๐๐ช๐ฃ๐ณ๐ช๐ฐ ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช, an emerging human pathogen is associated with cases of acute gastroenteritis. While ๐๐ช๐ฃ๐ณ๐ช๐ฐ ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช infections are traditionally considered rare, recent discoveries of multidrug-resistant strains have raised concerns regarding their clinical significance. This report provides a comprehensive analysis of key scientific findings regarding ๐๐ช๐ฃ๐ณ๐ช๐ฐ ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช infections, antibiotic resistance mechanisms, and virulence characteristics.
Methods:
Seven ๐๐ช๐ฃ๐ณ๐ช๐ฐ ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช strains were isolated from patients presenting with acute diarrhoea at a general hospital in Beijing, China, between April and October 2018. Genome analysis, antimicrobial susceptibility testing, and virulence phenotype assays were performed to characterize the isolates. Phylogenetic analysis based on single-nucleotide polymorphisms (SNPs) was conducted to elucidate the genetic relationships among the strains.
Key Findings:
- Genomic Insights:
- Phylogenetic analysis revealed a close relationship between ๐. ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช ๐ข๐ฏ๐ฅ ๐. ๐ง๐ญ๐ถ๐ท๐ช๐ข๐ญ๐ช๐ด strains forming distinct monophyletic clades.
- Whole-genome sequencing identified transposon islands containing antibiotic resistance genes on multi-drug resistance plasmids and chromosomes, highlighting the potential for horizontal gene transfer and dissemination of resistance determinants.
2. Antimicrobial Resistance:
- ๐๐ช๐ฃ๐ณ๐ช๐ฐ ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช isolates exhibited high resistance rates to cefazolin, tetracycline, and streptomycin, with intermediate resistance to ampicillin/sulbactam and imipenem.
- Multi-drug resistance was observed in several strains, posing challenges for effective antibiotic therapy.
- Resistance to carbapenems, including imipenem and meropenem, was detected in VFBJ02, indicating the emergence of carbapenem-resistant ๐๐ช๐ฃ๐ณ๐ช๐ฐ ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช strains.
3. Virulence Phenotypes:
- ๐๐ช๐ฃ๐ณ๐ช๐ฐ ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช strains encoded key virulence factors, including the type VI secretion system (T6SS), haemolysins, metalloproteases, and iron-regulated outer membrane proteins.
- Phenotypic assays confirmed the expression of an active T6SS and strong beta-haemolysis on blood agar, suggesting potential pathogenicity in human hosts.
4. Clinical Epidemiology:
- Diarrhoea associated with ๐๐ช๐ฃ๐ณ๐ช๐ฐ ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช infections occurred sporadically, with cases more prevalent during the summer months in Beijing, China.
- Seafood consumption was identified as a potential source of ๐๐ช๐ฃ๐ณ๐ช๐ฐ ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช contamination, highlighting the importance of food safety measures.
- Treatment Implications:
- Fluoroquinolones and third-generation cephalosporins, such as ceftazidime and doxycycline, were effective in treating ๐๐ช๐ฃ๐ณ๐ช๐ฐ ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช infections.
- However, the emergence of multi-drug resistant strains underscores the importance of judicious antibiotic use and continuous surveillance efforts.
This study provides valuable insights into the genomic, antimicrobial resistance, and virulence characteristics of ๐๐ช๐ฃ๐ณ๐ช๐ฐ ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช, shedding light on its clinical significance and potential treatment strategies. Continued laboratory-based surveillance is essential for monitoring the spread of antibiotic resistance and implementing effective control measures. Future research should focus on elucidating the molecular mechanisms underlying antibiotic resistance and virulence in ๐๐ช๐ฃ๐ณ๐ช๐ฐ ๐ง๐ถ๐ณ๐ฏ๐ช๐ด๐ด๐ช๐ช to inform targeted therapeutic interventions and public health policies.
Link to the article : https://tinyurl.com/y5efysea
