ABSTRACT:In recent years ,there has been high prevalence of murine typhus in Yunnan Province ,People's Republic of China .A large outbreak of murine typhus occurred in Xishuangbanna Prefecture ,Yunnan Province in 2010 .However ,not all cases were confirmed by laboratory assays ;therefore ,field epidemiologic and laboratory investigations of murine typhus in Xishuangbanna Prefecture were conducted in 2011 .Blood samples were collected from clinical diagnostic cases at the acute and convalescence stages of murine typhus in Xishuangbanna Prefecture ,Yunnan Province ,from June to September of 2011 ,and blood and spleen samples were collected from mice sharing the same habitats as the patients .Immunofluorescence assays were used to test for the presence of IgM and IgG antibodies against Rickettsia typhi in sera from patients and mice .Real‐time PCR was used to detect the groEL gene of R .typhi in blood clots from patients at the acute stage and in spleen tissue from mice .A total of 1 157 clinically diagnosed murine typhus cases occurred in Xishuangbanna Prefecture ,Yunnan Province in 2011 ,with an incidence of 102 .10/100 000 .Of these cases ,80 were investigated by laboratory assays and 74 of 80 patients were confirmed to have murine typhus .The coincidence rate between the clinical diagnosis and laboratory detection was 92 .50% .The positivi‐ty rate for IgG antibodies against R .typhi was 14 .0% (14/100) for Rattus f lavipectus ,while the rate by PCR was 9 .0%(9/100) .That laboratory diagnoses confirmed that the severity of the murine typhus outbreak in Xishuangbanna cannot be ig‐nored .The distribution of host animals transmitting R .typhi underscores this conclusion .

OBJECTIVE： To investigate the effects of different polar parts of 5 kinds of Alpinia on the function of sympathetic-adrenal system in gastric ulcer model rats with cold syndrome， such as the root of Alpinia officinarum， the rhizome and fruit of Alpinia galangal， the seed of Alpinia katsumadai， and the fruit of Alpinia oxyphylla. METHODS： SD rats were given Anemarrhena asphodeloides decoction at 4 ℃ and Glacial acetic acid solution intragastrically to induce gastric ulcer model with cold syndrome； the model rats were randomly divided into model group， Fuzi lizhong pills group （positive control， 9.0 g/kg）， cimetidine group （positive control， 0.003 3 g/kg）， low-dose and high-dose groups of petroleum ether， ethyl acetate， n-butanol and water extraction parts from 5 medicinal materials （hereinafter referred to as “gaoshidi” “gaoshigao” “dashidi” “dashigao” “hongshidi” “hongshigao” “caoshidi” “caoshigao” “yishidi” “yishigao” “gaoyidi” “gaoyigao” “dayidi” “dayigao” “hongyidi” “hongyigao” “caoyidi” “caoyigao” “yiyidi” “yiyigao” “gaozhengdi” “gaozhenggao” “dazhengdi” “dazhenggao” “hongzhengdi” “hongzhenggao” “caozhengdi” “caozhenggao” “yizhengdi” “yizhenggao” “gaoshuidi” “gaoshuigao” “dashuidi” “dashuigao” “hongshuidi” “hongshuigao” “caoshuidi” “caoshuigao” “yishuidi” “yishuigao”， 0.064/0.256， 0.032/ 0.128， 0.008/0.032， 0.075/0.3， 0.1/0.4， 0.064/0.256， 0.108/0.432， 0.16/0.64， 0.064/0.25， 0.125/0.5， 0.056/0.224， 0.108/0.432， 0.08/0.32， 0.2/0.8， 0.3/1.2， 0.14/0.56， 0.032/0.128， 0.028/0.112， 0.05/0.2， 0.087/0.348 g/kg， by mass of extraction parts）， with 10 rats in each group； and the blank group （normal temperature water） was set up. Next day after modeling， blank group and model group were given constant volume of normal temperature water intragastrically； administration group was given relevant solution 2 mL/100 g intragastrically， q12 h， 4 times in total. After last medication， urine contents of 17-OHCS， CAs substances （A， NE， DA） and serum contents of ACTH and D-β-H were determined by ELISA. RESULTS： Compared with blank group， the contents of 17-OHCS， A， NE and DA in urine， the contents of ACTH and D-β-H in serum were decreased significantly in model group （P＜0.01）. Compared with model group， the contents of 17-OHCS （Fuzi lizhong pills group， cimetidine group， gaoshidi， gaoshigao， dashigao， hongshigao， caoshigao and yishigao groups， ethyl acetate part groups of 5 medicinal materials， dazhenggao， hongzhenggao， caozhenggao and yizhenggao groups， gaoshuigao， dashuigao and hongshuigao groups）， A （Fuzi lizhong pills group， cimetidine group， gaoshigao， dashigao， hongshidi， hongshigao， caoshidi， caoshigao and yishigao groups， ethyl acetate part groups of 5 medicinal materials， gaozhenggao， dazhenggao， hongzhengdi， hongzhenggao， caozhenggao and yizhenggao groups， hongshuigao group）， NE （Fuzi lizhong pills group， cimetidine group， petroleum ether part， ethyl acetate part and n-butanol part groups of 5 medicinal materials， gaoshuigao， dashuigao and hongshuigao groups）， DA [Fuzi lizhong pills group， cimetidine group， petroleum ether part （except for gaoshidi group） and ethyl acetate part groups of 5 medicinal materials， gaozhenggao， dazhenggao， hongzhenggao， caozhenggao and yizhenggao groups， hongshuigao group] in urine， serum contents of ACTH [Fuzi lizhong pills group， petroleum ether part （except for gaoshidi， dashidi and caoshidi groups） and ethyl acetate part （except for dayidi and hongyidi groups） groups of 5 medicinal materials， hongzhenggao group， dashuigao group]， and D-β-H [Fuzi lizhong pills group， gaoshigao， dashigao， hongshidi， hongshigao and yishigao groups， ethyl acetate part groups of 5 medicinal materials （except for dayidi， hongyidi and yiyidi groups）， dazhenggao and hongzhenggao groups， hongshuigao group] were increased significantly （P＜0.05 or P＜0.01）. The contents of 17-OHCS and D-β-H in dashigao group， the contents of ACTH and D-β-H in caoshigao group and the contents of D-β-H in gaoshigao and yishigao groups were significantly lower than hongshigao group. The contents of DA in gaoyigao， caoyigao and yiyigao groups as well as the contents of D-β-H in gaoyigao， hongyigao， caoyigao and yiyigao groups were significantly lower than dayigao group； the contents of DA in gaoyigao and caoyigao groups were significantly lower than hongyigao group， the contents of ACTH in gaoyigao， dayigao， caoyigao and yiyigao groups were significantly higher than hongyigao group. The contents of 17-OHCS， DA and ACTH in gaozhenggao， dazhenggao， caozhenggao and yizhenggao groups， the contents of A in dazhenggao， caozhenggao and yizhenggao groups as well as the contents of D-β-H in gaozhenggao， caozhenggao and yizhenggao groups were significantly lower than hongzhenggao group. The contents of 17-OHCS and D-β-H in caoshuigao and yishuigao groups were significantly lower than dashuigao group. The contents of 17-OHCS， DA and D-β-H in caoshuigao and yishuigao groups as well as the contents of DA and D-β-H in gaoshuigao groups were significantly lower than hongshuigao group （P＜0.05 or P＜0.01）. CONCLUSIONS： Different polar parts of 5 kinds of Alpinia can improve gastric ulcer model rats with cold syndrome to different extents； among them， the fruit of A. galangal is the best， followed by the root of A. officinarum. Above medicinal materials can regulate the function of sympathetic-adrenal system by increasing the contents of 17-OHCS， CAs and D-β-H.

Objective To investigate the antimicrobial resistance profile of the clinical isolates collected from selected hospitals across China. Methods Twenty-nine general hospitals and five children's hospitals were involved in this program. Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems. Results were interpreted according to CLSI 2017 breakpoints. Results A total of 190 610 clinical isolates were collected from January to December 2017, of which gram negative organisms accounted for 70.8％ (134 951/190 610) and gram positive cocci 29.2％ (55 649/190 610). The prevalence of methicillin-resistant strains was 35.3％ in S. aureus (MRSA) and 80.3％ in coagulase negative Staphylococcus (MRCNS) on average. MR strains showed much higher resistance rates to most of the other antimicrobial agents than MS strains. However, 91.6％ of MRSA strains were still susceptible to trimethoprim-sulfamethoxazole, while 86.2％ of MRCNS strains were susceptible to rifampin. No staphylococcal strains were found resistant to vancomycin. E. faecalis strains showed much lower resistance rates to most of the drugs tested (except chloramphenicol) than E. faecium. Vancomycin-resistant Enterococcus (VRE) was identified in both E. faecalis and E. faecium. The identified VRE strains were mainly vanA, vanB or vanM type based on phenotype or genotype. The proportion of PSSP or PRSP strains in the non-meningitis S.pneumoniae strains isolated from children decreased but the proportion of PISP strains increased when compared to the data of 2016. Enterobacteriaceae strains were still highly susceptible to carbapenems. Overall, less than 10％ of these strains (excluding Klebsiella spp.) were resistant to carbapenems. The prevalence of imipenem-resistant K. pneumoniae increased from 3.0％ in 2005 to 20.9％ in 2017, and meropenem-resistant K. pneumoniae increased from 2.9％ in 2005 to 24.0％ in 2017, more than 8-fold increase. About 66.7％ and 69.3％ of Acinetobacter (A. baumannii accounts for 91.5％) strains were resistant to imipenem and meropenem, respectively. Compared with the data of year 2016, P. aeruginosa strains showed decreasing resistance rate to carbapenems. Conclusions Bacterial resistance is still on the rise. It is necessary to strengthen hospital infection control and stewardship of antimicrobial agents. The communication between laboratorians and clinicians should be further improved in addition to surveillance of bacterial resistance.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.

Objective To investigate the changing distribution and antibiotic resistance profiles of clinical isolates of Staphylococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Staphylococcus according to the unified protocol of CHINET(China Antimicrobial Surveillance Network)using disk diffusion method and commercial automated systems.The CHINET antimicrobial resistance surveillance data from 2015 to 2021 were interpreted according to the 2021 CLSI breakpoints and analyzed using WHONET 5.6.Results During the period from 2015 to 2021,a total of 204,771 nonduplicate strains of Staphylococcus were isolated,including 136,731(66.8％)strains of Staphylococcus aureus and 68,040(33.2％)strains of coagulase-negative Staphylococcus(CNS).The proportions of S.aureus isolates and CNS isolates did not show significant change.S.aureus strains were mainly isolated from respiratory specimens(38.9±5.1)％,wound,pus and secretions(33.6±4.2)％,and blood(11.9±1.5)％.The CNS strains were predominantly isolated from blood(73.6±4.2)％,cerebrospinal fluid(12.1±2.5)％,and pleural effusion and ascites(8.4±2.1)％.S.aureus strains were mainly isolated from the patients in ICU(17.0±7.3)％,outpatient and emergency(11.6±1.7)％,and department of surgery(11.2±0.9)％,whereas CNS strains were primarily isolated from the patients in ICU(32.2±9.7)％,outpatient and emergency(12.8±4.7)％,and department of internal medicine(11.2±1.9)％.The prevalence of methicillin-resistant strains was 32.9％in S.aureus(MRSA)and 74.1％in CNS(MRCNS).Over the 7-year period,the prevalence of MRSA decreased from 42.1％to 29.2％,and the prevalence of MRCNS decreased from 82.1％to 68.2％.MRSA showed higher resistance rates to all the antimicrobial agents tested except trimethoprim-sulfamethoxazole than methicillin-susceptible S.aureus(MSSA).Over the 7-year period,MRSA strains showed decreasing resistance rates to gentamicin,rifampicin,and levofloxacin,MRCNS showed decreasing resistance rates to gentamicin,erythromycin,rifampicin,and trimethoprim-sulfamethoxazole,but increasing resistance rate to levofloxacin.No vancomycin-resistant strains were detected.The prevalence of linezolid-resistant MRCNS increased from 0.2％to 2.3％over the 7-year period.Conclusions Staphylococcus remains the major pathogen among gram-positive bacteria.MRSA and MRCNS were still the principal antibiotic-resistant gram-positive bacteria.No S.aureus isolates were found resistant to vancomycin or linezolid,but linezolid-resistant strains have been detected in MRCNS isolates,which is an issue of concern.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.