Objective To understand the clinical distribution characteristics and drug-resistance genotypes of carbapenem-resistant Pseudomonas aeruginosa(CRPA)in a tertiary hospital in Shanghai,so as to guide the rational use of antibiotics,reduce bacterial resistance and control nosocomial infections.Methods A total of 94 consecutive and non-redundant CRPA strains isolated from clinical specimens were collected in The First Affiliated Hospital of Naval Medical University between Jan.1,and Dec.31,2019.The distribution of CRPA across departments and sample sources were analyzed.Antimicrobial susceptibility testing against 13 antibiotics was determined using the VITEK 2 Compact automated microbiology analyzer and the Kirby-Bauer disk diffusion method.Polymerase chain reaction(PCR)was employed to detect genes encoding extended-spectrum β-lactamase resistance gene,carbapenemase resistance gene,and porin resistance gene.Homology analysis of selected isolates was performed using kSNP3,a k-mer-based software,for single nucleotide polymorphism(SNP)analysis.An evolutionary tree was constructed to assess genetic relationships.Additionally,multilocus sequence typing(MLST)was performed using the Pseudomonas aeruginosa typing scheme from the PubMLST database.Results Among the 94 CRPA isolates,high resistance rates were observed for carbapenems,including imipenem(92.6%,87 strains)and meropenem(87.2%,82 strains).In contrast,low resistance rates were detected for aminoglycosides,such as amikacin(10.6%,10 strains),gentamicin(20.2%,19 strains),and tobramycin(20.2%,19 strains).The top 3 departments in terms of isolate distribution were the Emergency Intensive Care Unit(9.6%,9 strains),Department of Cerebrovascular Surgery(8.5%,8 strains),and Department of Respiratory Medicine(8.5%,8 strains).PCR analysis of 94 CRPA strains detected outer membrane protein D2(OprD2)gene deletion in 47(50.0%)strains,13(13.8%)strains were positive for blaKPC,4(4.3%)strains for blaVIM,2(2.1%)strains for blaIMP,1(1.1%)strain for blaNDM,12(12.8%)strains for blaTEM,4(4.3%)strains for blaPER,and 2(2.1%)strains for blaGES,while blaOXA-48,blaBIC,blaSIM,blaVEB,and blaSHV were not detected.MLST identified 36 different sequence types(STs),with ST463 and ST274 being the most common,and 2 new ST(ST4023 and ST4024)were identified for the first time.Conclusion CRPA strains carry multiple resistance genes and exhibit concurrent resistance to several commonly used clinical antibiotics.The resistance is primarily associated with the presence of blaKPC,blaVIM and blaTEM genes and the deletion of OprD2 gene.Clinical monitoring of CRPA should be strengthened,and rational use of antimicrobial agents is essential to control its spread within the hospital.

Objective To monitor the antifungal resistance of clinical isolates of Candida spp.in the East China region.Methods MALDI-TOF MS or molecular methods were used to re-identify the strains collected from January 2018 to December 2022.Antifungal susceptibility testing was performed using the broth microdilution method.The susceptibility test results were interpreted according to the breakpoints of 2022 Clinical and Laboratory Standards Institute(CLSI)documents M27 M44s-Ed3 and M57s-Ed4.Results A total of 3 026 strains of Candida were collected,65.33％of which were isolated from sterile body sites,mainly from blood(38.86％)and pleural effusion/ascites(10.21％).The predominant species of Candida were Candida albicans(44.51％),followed by Candida parapsilosis complex(19.46％),Candida tropicalis(13.98％),Candida glabrata(10.34％),and other Candida species(0.79％).Candida albicans showed overall high susceptibility rates to the 10 antifungal drugs tested(the lowest rate being 93.62％).Only 2.97％of the strains showed dose-dependent susceptibility(SDD)to fluconazole.Candida parapsilosis complex had a SDD rate of 2.61％and a resistance rate of 9.42％to fluconazole,and susceptibility rates above 90％to other drugs.Candida glabrata had a SDD rate of 92.01％and a resistance rate of 7.99％to fluconazole,resistance rates of 32.27％and 48.24％to posaconazole and voriconazole non-wild-type strains(NWT),respectively,and susceptibility rates above 90％to other drugs.Candida tropicalis had resistance rates of 29.55％and 26.24％to fluconazole and voriconazole,respectively,resistance rates of 76.60％and 21.99％to posaconazole and echinocandins non-wild-type strains(NWT),and a resistance rate of 2.36％to echinocandins.Conclusions The prevalence and species distribution of Candida spp.in the East China region are consistent with previous domestic and international reports.Candida glabrata exhibits certain degree of resistance to fluconazole,while Candida tropicalis demonstrates higher resistance to triazole drugs.Additionally,echinocandins resistance has emerged in Candida albicans,Candida glabrata,Candida tropicalis,and Candida parapsilosis.