High prevalence of blaTEM-135 and genetic epidemiology of blaTEM-135-carrying Neisseria gonorrhoeae isolates in Shandong, China, 2017-19

Emerging epidemic of the Africa-type plasmid in penicillinase-producing Neisseria gonorrhoeae in Guangdong, China, 2013-2022

The prevalence of penicillinase-producing Neisseria gonorrhoeae (PPNG) is a crucial public health concern because of its resistance to penicillin and cephalosporins. From 2013 to 2022, a total of 1748 N. gonorrhoeae isolates from Guangdong, China, were examined for their antibiotic susceptibility and molecular epidemiological characteristics. PPNG prevalence increased markedly from 37.25% to 63.87%. This increase was accompanied by a shift in predominant plasmid types carried by PPNG isolates: the rate of PPNG isolates carrying the Africa-type plasmid increased from 18.42% to 91.55%, whereas the rate of isolates carrying the Asia-type plasmid decreased from 81.58% to 7.58%. The prevalence of blaTEM-135, which is linked to cephalosporin resistance, declined from 52.63% to 4.37%, whereas that of blaTEM-1 increased from 47.37% to 86.88%, and new blaTEM variants emerged (10.99% by 2022). Most blaTEM-1 (88.26%) and new blaTEM alleles (83.70%) were associated with the Africa-type plasmid, whereas 86.79% of blaTEM-135 alleles were linked to the Asia-type plasmid. Resistance to ceftriaxone was higher in the Asia-type group (11.67%) than in the Africa-type, Toronto/Rio-type and non-PPNG groups. Genotyping identified diverse sequence types (STs) among PPNGs, in which MLST ST7363, NG-STAR ST2477, NG-MAST ST17748, and NG STAR CC1124 were predominant. This study underscores the rising prevalence of PPNG in Guangdong driven by clonal expansion and changing plasmid dynamics, affecting cephalosporin resistance and highlighting the need for continued surveillance and research into effective treatment strategies.

Current status of β-lactam antibiotic use and characterization of β-lactam-resistant Escherichia coli from commercial farms by integrated broiler chicken operations in Korea

β-Lactam antibiotics are one of the most clinical importance in human and veterinary medicine because they are used for both preventive and therapeutic purposes against several gram-positive, gram-negative, and anaerobic organisms. In this study, it was confirmed that β-lactams (81.1%) were found to be significantly prescribed the most among 74 farms in 5 integrated broiler operations, and single prescription (84.6%), 2-day (41.5%) or 3-day (40.0%) administration, and 15 to 22 d of age (67.7%) administration was significantly higher in the farms (P < 0.05). Among the E. coli isolated from 74 farms in 5 integrated broiler operations, β-lactam-resistant E. coli isolates were detected more frequently in fecal sample (94.6%) than in dust sample (60.8%) (P < 0.05). The prevalence of MDR in β-lactam-resistant isolates, ranging from 88.1 to 96.5%, was significantly higher than that in non-β-lactam-resistant isolates (P < 0.05), without significant differences among operations. Of 466 β-lactam-resistant isolates, 432 (92.7%) isolates harbored β-lactamase genes. The non-extended-spectrum β-lactamase (ESBL) gene blaTEM-1 (81.8%) showed the highest prevalence among isolates, followed by the non-ESBL gene blaTEM-135 (6.4%) (P < 0.05). Five ESBL genes, SHV-12, OXA-1, CTX-M-27, CTX-M-55, and CTX-M-65, were found in 0.9 to 6.0% of the isolates. The pAmpC gene blaCMY-2 was detected in 17 isolates (3.6%). These results suggest that feces and dust are important reservoirs of antimicrobial-resistant bacteria, highlighting the need to strengthen farm management regulations, such as cleaning, disinfection, and litter disposal and to reduce the use of antibiotics in broiler operations.

Antimicrobial susceptibilities and genomic epidemiology of Neisseria gonorrhoeae in Stockholm, Sweden

The aim of this study was to investigate the genomic epidemiology and antimicrobial susceptibilities of N. gonorrhoeae isolates in Stockholm, Sweden. In total, 6723 isolates detected in Stockholm, Sweden, from January 2016 to September 2022, were examined for antimicrobial susceptibilities by using E-test. Whole-genome sequencing (WGS) was applied to isolates in sentinel surveillance and isolates resistant to extended-spectrum cephalosporins (ESCs) or high-level azithromycin (HLAzi-R, MIC ≥ 256 mg/L). As sentinel surveillance, consecutive clinical isolates (n = 396) detected every 4th week from January 2021 to September 2022 were enrolled in the study. Of the 6723 isolates investigated, 33 isolates (< 1%) were found to be resistant to cefixime, one of which was co-resistant to ceftriaxone and ciprofloxacin and was detected in September 2022. Ten isolates presented a high level of azithromycin resistance. Resistant rates to ciprofloxacin varied from 32 in 2017 to 68-69% in 2021-2022. Elevated MIC50 and MIC90 of azithromycin were observed over the years. No resistance to spectinomycin was identified. The most frequently occurring MLST in the sentinel surveillance was ST9362 (23%), followed by ST11706 (9%), ST7359 (8%), ST10314 (7%), and ST11422 (6%). The ceftriaxone-resistant isolate belonged to ST8130 and the novel NG-STAR ST4859. Genomic resistance traits found in this strain included mutations in genes mtrR (A39T), parC (S87N), and gyrA (S91F and D95A), as well as the presence of blaTEM-135 and tetM genes. A predominance of ST9362 was observed in Stockholm. The high number of azithromycin and ciprofloxacin-resistant isolates and the emergence of a strain with a novel NG-STAR are of great concern.

Antibiotic Resistance in Neisseria gonorrhoeae: Challenges in Research and Treatment

Gonococcal infection caused by the Gram-negative bacteria Neisseria gonorrhoeae is one of the most common sexually transmitted infections (STIs) worldwide [...]