New Microbes and New Infections (Mar 2023)

Prevalence of silver resistance determinants and extended-spectrum β-lactamases in bacterial species causing wound infection: First report from Bangladesh

  • Kazi Sarjana Safain,
  • Mohammad Sazzadul Islam,
  • Jumanah Amatullah,
  • Mohammad Al Mahmud-Un-Nabi,
  • Golam Sarower Bhuyan,
  • Jakia Rahman,
  • Suprovath Kumar Sarker,
  • Md Tarikul Islam,
  • Rosy Sultana,
  • Firdausi Qadri,
  • Kaiissar Mannoor

Journal volume & issue
Vol. 52
p. 101104

Abstract

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Background: The use of silver is rapidly rising in wound care and silver-containing dressings are widely used along with other antibiotics, particularly β-lactams. Consequently, concerns are being raised regarding the emergence of silver-resistance and cross-resistance to β-lactams. Therefore, this study aimed to determine the phenotypic and genotypic profiles of silver-resistance and extended-spectrum β-lactamases in isolates from chronic wounds. Methods: 317 wound swab specimens were collected from tertiary hospitals of Dhaka city and analysed for the microbial identification. The antibiotic resistance/susceptibility profiles were determined and phenotypes of silver resistant isolates were examined. The presence of silver-resistance (sil) genes (silE, silP, and silS) and extended-spectrum β-lactamases (ESBL) (CTX-M-1, NDM-1, KPC, OXA-48, and VIM-1) were explored in isolated microorganisms. Results: A total of 501 strains were isolated with Staphylococcus aureus (24%) as the predominant organism. In 29% of the samples, polymicrobial infections were observed. A large proportion of Enterobacterales (59%) was resistant to carbapenems and a significantly high multiple antibiotic-resistance indexes (>0.2) were seen for 53% of organisms (P ​< ​0.001). According to molecular analysis, the most prevalent types of ESBL and sil gene were CTX-M-1 (47%) and silE (42%), respectively. Furthermore, phenotypic silver-nitrate susceptibility testing showed significant minimum-inhibitory-concentration patterns between sil-negative and sil-positive isolates. We further observed co-occurrence of silver-resistance determinants and ESBLs (65%). Conclusions: Notably, this is the first-time detection of silver-resistance along with its co-detection with ESBLs in Bangladesh. This research highlights the need for selecting appropriate treatment strategies and developing new alternative therapies to minimize microbial infection in wounds.

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