The Molecular Epidemiology And The Resistance Mechanisms Of Streptococcus Pneumoniae And Haemophilus Influenzae Causing Adults Infection In Shanghai

Streptococcus pneumoniae and Haemophilus infulenzae are two common fastidious pathogens causing respiratory tract infection and invasive infection among adult patients together with great economic burden to patients.In recent years,antimicrobial resistance has been prevalent as the widespread use of antibiotics.Moreover,the lack of standard sampling and detection led to low positive rate in clinical specimens and the lack of extensive pathogen susceptibility tests.Limited surveys on epidemiology of H.influenzae and S.pneumoniae among adult patients were found in China,which cannot provide efficient evidence in formulating relevant health policies.At present,domestic clinical laboratories have not been widely equipped with special testing reagent and equipment for antimicrobial susceptibility test of H.influenzae and S.pneumoniae.Therefore,we conducted a multicenter retrospective study on evaluation of domestic drug susceptibility kits for two fastidous bacterias,and serotype,antimirobial susceptibility,molecular epidemiology of S.pneumoniae and H.influenzae among adult patients in Shanghai.（1）Evaluation of antimicrobial suscepitibiliy kits of H.influenzae and S.pneumoniae:A total of 96 and 101 H.influenzae and S.pneumoniae isolates were collected.The overall CA,EA,MD and VMD of NH-AST were 97.80%,95.38%,2.07%and 3.29%,respectively.and the overall CA,EA,MD and VMD of STR-AST were 96.1%,99.6%,0.2%and 0%,respectively.（2）Molecular epidemiology and antimicrobial resistance analysis of S.pneumoniae:A total of 75 isolates from adult patients from three general hospitials in Shanghai from2015 to 2017 were involved.Antimicrobial susceptibility tests（microbroth dilution）,serotyping,MLST and strain homology analysis（e BURST software）were conducted.The top three prevalent serotypes were 19F（20.00%）,3（16.00%）and 23F（9.33%）.The prevalence of pneumococcal strains with serotypes targeted by vaccines PCV7,PCV10,PCV13,and PPV23 was 44,45.33,66.67,and 80.00%,respectively.The resistant rates to macrolids,clindamycin and tetracycline were over 80%and the resistant rates to cefaclor and trimethoprim-sulfamethoxazole were over 50%.Penicillin non-susceptible S.pneumoniae（PNSSP）were 16.00%.Spain^23F-1、Netherland³-31和Taiwan^19F-14 were predominant international resistant clones in Shanghai.（3）Molecular epidemiology and antimicrobial resistance analysis of H.influenzae:A total of 213 isolates from adult patients from four general hospitals in Shanghai from 2015to 2018 were involved.Antimicrobial susceptibility tests（microbroth dilution）,drug-resistance gene amplification,serotyping,MLST and strain homology analysis（phyloviz software）were conducted.Nontypeable H.influenzae（NTHi）（99.06%）were predominant in adult patients infected with H.influenzae.The top three resistant rates to trimethoprim-sulfamethoxazole,ampicillin and cefutoxime were 49.3%,39.44%and 33.33%,respectively.28.58%of the isolates producedβ-lactamase of TEM-1.Phenotypic BLNAR isolates accounted for 9.86%,with BLPACR for 5.16%.Amino acid substitutions in PBP3widely distributed in these isoltates.Genetically,BLPAR strains were 5.63%of the isolates and genetic BLNAR were 77.00%.Genetic diversity showed no envidence suggesting specific clonal spread.However,the emergency of CC503（12.6%）,CC11（7.98%）,CC14（5.63%）,and CC12（7.51%）may contribute to the spread of BLNAR strains.In conclusion,the domastic antimicrobial susceptibility kits were reliable in clinical practice.Multiclonal spread were found in S.pneumoniae among adult patients in Shanghai.the rate of penicillin non-susceptible were high and multidrug resistance were severe.Although multiclonal spread were also found in H.influenzae among adult patients in Shanghai,the emergency of certain clonal complexes need more attention.Low-BLNAR were prevalent in Shanghai,with high resistant rates of ampicillin and trimethoprim-sulfamethoxazole.Long-term surveillance of S.pneumoniae and H.influenzae were essential.