Analysis on Bacterial Distribution and Change of Drug Resistance Rate in ICUs Across Southwest China from 2018 to 2022.

Purpose: To analyze the distribution of bacteria and their drug resistance changes in Intensive Care Units (ICUs) across Southwest China from 2018 to 2022 and establish the antibiogram in this region to provide a basis for early empirical antimicrobial use. Methods: Non-repetitive pathogens isolated from 109 member units with qualified data were obtained from the Antimicrobial Resistance Surveillance System in Sichuan Province, southwest China. The results obtained were interpreted with reference to CLSI M100-31th, and analyzed with WHONET 5.6 software. Results: A total of 46,728 clinical isolates in ICUs were collected from 2018 to 2022, of which gram-negative organisms accounted for 76.1%, and gram-positive were 23.9%. The top 5 were Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, respectively. From 2018 to 2022, the resistance rates of Klebsiella pneumoniae to imipenem and meropenem changed from 14.5% and 17.8% to 14.0% and 14.4%, showing a steady downward trend. Escherichia coli was always highly sensitive to carbapenems, with a total resistance rate of 3.8%. Among non-fermented gram-negative bacteria, the resistance rates of Pseudomonas aeruginosa to imipenem and meropenem decreased significantly, changed from 25.3% and 22.9% in 2018 to 20.0% and 15.1% in 2022. However, Acinetobacter baumannii showed high resistance rates of 76.2% and 76.9% to imipenem and meropenem, respectively. MRSA and MRCNS accounted for 31.7% and 82.7%, respectively. No vancomycin and linezolid-resistant Staphylococcus aureus was isolated. Enterococcus faecalis maintained high activity to vancomycin, teicoplanin, and linezolid; no vancomycin or teicoplanin-resistant Enterococcus faecium strains were detected. Conclusion: From 2018 to 2022, the isolated bacteria in ICU were mainly gram-negative bacteria, and the growth of some multidrug-resistant bacteria was effectively controlled. All levels of medical institutions should continue to strengthen bacterial resistance surveillance, promote the establishment of antimicrobial stewardship program, and enhance restrictions on outpatient antimicrobial use.

Comparison of the Distribution and Changes in the Antibiotic Resistance of Clinical Bacterial Isolates from the Lower Respiratory Tract of Children in Shenzhen Before the Epidemic, During the Epidemic, and During the Period of Normalized Prevention and Control of COVID-19.

INTRODUCTION: This study aimed to understand the impact of the coronavirus disease 2019 (COVID-19) epidemic on the distribution and antibiotic resistance of pathogenic bacteria isolated from the lower respiratory tract of children in our hospital. METHODS: Antimicrobial susceptibility tests were performed on bacteria isolated clinically from the lower respiratory tracts of children in our hospital from 2018 to 2021 by the Kirby-Bauer method and automated systems. RESULTS: From 2018 to 2021, the top three lower respiratory tract clinical isolates in our hospital were Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae. These three species showed obvious seasonal epidemic patterns, and their numbers decreased significantly during the COVID-19 epidemic, from 4559 in 2019 to 1938 in 2020. Bacterial resistance to antibiotics also changed before and after the COVID-19 epidemic. The annual proportions of methicillin-resistant S. aureus (MRSA) were 41%, 37.4%, 26.2%, and 29.8%. The resistance rates of Klebsiella pneumoniae to ceftriaxone were 40.5%, 51.9%, 35.3%, and 53.3%, and the detection rates of carbapenem-resistant K. pneumoniae (CRKP) were 2.7%, 11.1%, 5.9%, and 4.4%. The detection rates of ß-lactamase-producing H. influenzae were 51.9%, 59.2%, 48.9%, and 55.3%. The rate of MRSA, ceftriaxone-resistant K. pneumoniae, CRKP, and ß-lactamase-producing H. influenzae decreased significantly in 2020 compared with 2019, whereas that of carbapenem-resistant P. aeruginosa and carbapenem-resistant A. baumannii increased. The detection rates of ß-lactamase-negative ampicillin-resistant H. influenzae (BLNAR) gradually increased over the 4 years. CONCLUSIONS: Protective measures against COVID-19, including reduced movement of people, hand hygiene, and surgical masks, may block the transmission of S. pneumoniae, H. influenzae, and M. catarrhalis and reduce the detection rate of MRSA, ceftriaxone-resistant K. pneumoniae, CRKP, and ß-lactamase-producing H. influenzae.

Multicenter Antimicrobial Resistance Surveillance of Clinical Isolates from Major Hospitals - China, 2022.

What is already known about this topic?: Bacterial resistance surveillance is crucial for monitoring and understanding the trends and spread of drug-resistant bacteria. What is added by this report?: The number of strains collected in 2022 increased compared to 2021. The top five bacteria, including Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii, remained largely unchanged. The detection rate of methicillin-resistant strains continued to decrease. Among clinical Enterobacterales isolates, the resistance rate to carbapenems was generally below 13%, except for Klebsiellaspp., which had a resistance range of 20.4% to 21.9%. Most clinical Enterobacterales isolates were highly susceptible to tigecycline, colistin, and polymyxin B, with resistance rates ranging from 0.1% to 12.6%. The detection rate of meropenem-resistant P. aeruginosa and meropenem-resistant Acinetobacter baumannii showed a decreasing trend for the fourth consecutive year. What are the implications for public health practice?: Multidrug-resistant bacteria remain a significant public health challenge in clinical antimicrobial treatment. To effectively address bacterial resistance, it is essential to enhance both bacterial resistance surveillance and the prudent use of antimicrobial agents.

[Epidemiological analysis of pathogens causing bloodstream infections in department of hematology in Guangdong Province].

Objective: To evaluate the epidemiology of bacterial bloodstream infections in patients submitted to hematologic wards in southern China. Methods: A total of 50 teaching hospitals were involved based on the China Antimicrobial Resistance Surveillance System. The data of clinical isolates from blood samples were collected from January 1, 2019, to December 31, 2019. Antimicrobial susceptibility testing was conducted by the Kirby-Bauer automated systems, and the results were interpreted using the CLSI criteria. Results: The data of 1,618 strains isolated from hematologic wards in 2019 were analyzed, of which gram-negative bacilli and gram-positive cocci accounted for 71.8% and 28.2%, respectively. Of those, the five major species were most often isolated, including Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, coagulase-negative staphylococcus, and Streptococcus viridans. The prevalence rates of methicillin-resistant strains in Staphylococcus aureus and coagulase-negative staphylococcus were 19.7% and 80.6%, respectively. No gram-positive cocci were resistant to vancomycin, linezolid, and teicoplanin, and none of the enterococci were resistant to linezolid. The resistance rate of S. viridans to penicillin G was 6.9%, and those to ceftriaxone and cefotaxime were more than 25%. The resistance rate of E. coli and K. pneumoniae in Enterobacteriaceae was higher in children than that in adults. The resistance rate of K. pneumoniae to meropenem was 14.1%. The resistant rate of Enterobacter cloacae to carbapenem was more than 25%. P. aeruginosa was more sensitive to more antibiotics than 80%, but the resistance rate to meropenem in children was higher than that in adults (11.8% vs. 6.5%). The proportion of gram-positive cocci in the ICU and respiratory departments was higher than that in the hematology department. The detection rates of carbapenem-resistant E. coli and K. pneumoniae in the respiratory department were the lowest with 0.3% and 3.7%, respectively, while those of CRPA and CRAB in the hematology department were the lowest with 8.3% and 25.8%, respectively. The detection rate of all carbapenem-resistant organisms in the ICU was the highest among the three departments. Conclusion: The etiology and drug resistance of bacteria from blood samples in the hematology department are different from those in the ICU and respiratory departments. The proportions of K. pneumoniae, P. aeruginosa, E. cloacae, and S. viridans dominating in the department of Hematology were significantly higher than those in the ICU and respiratory departments in Guangdong region.

Resistance reported from China antimicrobial surveillance network (CHINET) in 2018.

The aim of this study is to investigate the antimicrobial susceptibility of strains isolated from the major hospitals in China. A total of 44 teaching hospitals were involved. Antimicrobial susceptibility testing was conducted by Kirby-Bauer automated systems, and results were interpreted using CLSI criteria. Totally 244,843 strains were isolated in 2018, of which gram-negative bacilli and gram-positive cocci were accounting for 71.8% and 28.2%, respectively. 39.7% of isolates were cultured from lower respiratory tract, 18.8% from urine, 14.8% from blood, 1.3% from cerebrospinal fluid, respectively. Of those, the five major species were most often isolated (65.5%, 63%, 52.3%, and 30.3%). The resistance rate of MRSA to most antimicrobial agents was significantly higher than that of MSSA strains, except for to trimethoprim-sulfamethoxazole in urine specimen. E.coli was still highly susceptible to carbapenem antibiotics, and the resistance rate was less than 5%. Carbapenem resistance among Klebsiella pneumoniae, especially cultured from cerebrospinal fluid, increased significance from 18.6 to 64.1%. The resistance rates of Pseudomonas aeruginosa to carbapenems were nearly 30% in the blood, in urine, and in the lower respiratory tract, but about 60% of that in cerebrospinal fluid. About 80% of Acinetobacter baumannii strains was resistant to imipenem and meropenem, respectively. Bacterial resistance of five major clinical isolates from cerebrospinal fluid to common antibiotics (in particular Carbapenem-resistant Klebsiella pneumoniae) currently shows an increasing trend. It is worth to emphasize the importance of serious control of hospital infection and better management of clinical use of antimicrobial agents.

Surveillance of bacterial resistance in Yongzhou Central Hospital of Hunan in 2016 and 2017 / 中国感染与化疗杂志

Objective To investigate the susceptibility and resistance profile of clinical isolates in Hunan Yongzhou Hospital during 2016 and 2017. Methods Antimicrobial susceptibility testing was carried out according to a unified protocol using KirbyBauer method or automated systems. Results were analyzed according to CLSI 2016 breakpoints. Results A total of 6 354 clinical isolates were collected from January 2016 to December 2017, of which 4 876(76.7％)were gram-negative bacteria, and 1 478(23.3％)were gram-positive bacteria. The top five bacterial species were Escherichia coli(33.0％), Klebsiella(17.0％), Staphylococcus aureus(9.6％), Acinetobacter(8.6％), and Pseudomonas aeruginosa(7.4％). The prevalence of methicillin-resistant Staphylococcus aureus(MRSA)was 33.8％, and prevalence of methicillin-resistant coagulase negative Staphylococcus(MRCNS)was 76.2％. The resistance rates of methicillin resistant strains(MRSA and MRCNS)to most of the tested drugs were significantly higher than those of methicillin sensitive strains(MSSA and MSCNS). No vancomycin or linezolid resistant staphylococci were identified. The resistance rate of Enterococcus faecium to most antimicrobial agents was significantly lower than that of Enterococcus faecium. No enterococcal isolate was resistant to vancomycin or linezolid. The non-meningitis S. pneumoniae strains isolated from children showed slightly higher resistance rate to penicillin(20.8％)than the strains isolated from adults(13.3％). The prevalence of extended spectrum beta-lactamases(ESBLs)in Escherichia coli and Klebsiella pneumoniae was 48.0％ and 35.7％, respectively. Most Enterobacteriaceae strains were highly sensitive to carbapenem antibiotics, showing lower resistancerate(<4％). The prevalence of carbapenem-resistant Klebsiella pneumoniae was 18.8％, and the prevalence of carbapenem-resistant E. cloacae was 14.5％. The prevalence of Acinetobacter baumannii strain resistant to imipenem and meropenem was 76.4％ and 78.6％, respectively. Conclusions Bacterial resistance is still serious. It is necessary to strengthen the monitoring of bacterial resistance, infection control, and rational use of antibiotics.

Results of bacterial resistance surveillance in a Guangdong hospital during 2015-2017 / 中国感染与化疗杂志

Objective To investigate the susceptibility profile of clinical isolates in the First Affiliated Hospital of Guangzhou Medical University during 2015-2017. Methods Susceptibility test was carried out using Kirby-Bauer method or automated systems. Results were analyzed according to CLSI 2017 breakpoints. Results A total of 17 645 clinical isolates were isolated from January 2015 to December 2017, including 3 091(17.5％)gram positive and 14 554(82.5％)gram negative bacteria. Methicillinresistant S. aureus(MRSA)and coagulase-negative Staphylococcus(MRCNS)accounted for 50.7％ and 77.9％, respectively. No staphylococcal isolates were found resistant to vancomycin, teicoplanin or linezolid. E. faecalis strains showed much lower resistance rate to most drugs tested than E. faecium. Nine(0.8％)E. faecalis isolates were found resistant to vancomycin. A total of 227 strains of the non-meningitis S. pneumoniae were tested, 44.1％ of which were isolated from adults and 55.9％ from children. Most of the S. pneumoniae isolated from adults and children were susceptible to penicillin(88.0％ and 81.1％, respectively). E. coli showed the highest proportion in three years. ESBLs were produced in 53.3％ of E. coli and 28.5％ of Klebsiella spp. A total of 255 strains of carbapenem-resistant Enterobacteriaceae(3.7％), 665 strains of carbapenem-resistant Pseudomonas aeruginosa(26.2％)and 900 strains of carbapenem-resistant Acinetobacter baumannii(57.5％)were identified. The annual change of prevalence was insignificant. A total of 141 strains of extensively-drug resistant Pseudomonas aeruginosa(5.6％)and 458 strains of extensively-drug resistant A. baumannii(29.3％)were identified, showing decreasing prevalence from 2015 to 2017. Conclusions The bacterial resistance in this hospital is relatively stable in the past three years, but it is still necessary to strengthen hospital infection control and management, and maintain good practice in surveillance of bacterial resistance.

Antimicrobial resistance surveillance in Shanghai Children's Hospital from 2011 to 2016 / 中国感染与化疗杂志

Objective To investigate the distribution and resistance profile of bacterial isolates in Shanghai Children's Hospital. Methods Antimicrobial susceptibility of all isolates was determined by Kirby-Bauer disk diffusion method according to 2016 CLSI standard. The data were analyzed by WHONET 5.6 software. Results A total of 23 259 non-duplicate strains were isolated from 2011 to 2016, including 10 885(46.8％)gram-postive cocci and 12 374(53.2％)gram-negative bacilli. The average prevalence of methicillin-resistant S. aureus(MRSA)and coagulase-negative Staphylococcus(MRCNS)was 35.8％ and 82.2％, respectively. The prevalence of MRSA rose from 27.4％ in 2011 to 42.9％ in 2016. The resistance rate of MRSA and MRCNS strains were significantly higher than methicillin sensitive strains. The resistance rate of Enterococcus faecium strains was significant higher than Enterococcus faecalis. The prevalence of non-susceptible Streptococcus pneumoniae was 31.2％(908). No gram-positive strain was resistant to vancomycin or linezolid. The prevalence of carbapenem resistance increased in gram-negative strains. The resistance rate of Klebsiella pneumoniae to imipenem and meropenem rose from 3.1％ and 4.8 ％ in 2011 to 28.7％ and 37.4％ in 2016, respectively.The rate of Pseudomonas aeruginosa resistance to imipenem and meropenem rose from 13.8％ and 16.5％ in 2011 to 18.8％ and 19.4％ in 2016, respectively, while Acinetobacter baumannii showed resistance rate of 38.3％ and 39.9 ％ in 2011 to 68.4％ and 69.7％ in 2016. Conclusions Increasing prevalence of MRSA, carbapenem-resistant K. pneumoniae, extensively drug-resistant A.baumannii has become a concern in clinical practice. Therefore, antimicrobial resistance surveillance should be highly strengthened in children's hospital.

Surveillance of antibiotic resistance in clinical isolates from the First Affiliated Hospital of Anhui Medical University during 2017 / 中国感染与化疗杂志

Objective To investigate the antibiotic resistance of clinical isolates in the First Affiliated Hospital of Anhui Medical University during 2017. Methods Antimicrobial susceptibility testing was carried out according to a unified protocol using automated system or Kirby-Bauer method. Results were interpreted according to the breakpoints of CLSI 2017. The data were analyzed by WHONET 5.6 software. Results A total of 6 495 non-duplicate clinical isolates were collected in 2017. There were 1 727 strains (26.6％) of gram-positive bacteria and 4 768 strains (73.4％) of gram-negative bacteria. The most frequently isolated microorganisms were E. coli (19.8％), followed by Klebsiella pneumoniae and Acinetobacter baumannii. The strains were mainly isolated from respiratory tract (37.0％) and urine (23.1％). The prevalence of MRSA and MRCNS in Staphylococcus aureus and coagulase-negative Staphylococcus was 50.1％ and 82.1％, respectively. No Staphylococcus strains were found resistant to vancomycin or linezolid. E. faecalis and E. faecium accounted for 49.9％ and 40.4％ of total Enterococcus isolates. The prevalence of ESBLs-producing strains was 57.6％ in E. coli, 27.1％ in Klebsiella spp. and 33.0％ in Proteus mirabilis. Enterobacteriaceae strains were still highly susceptible to carbapenems antibiotics. The Klebsiella pneumoniae isolates in 2017 showed significantly higher resistance rate to imipenem and meropenem than the strains in 2016. However, Pseudomonas aeruginosa and Acinetobacterbaumannii strains showed lower resistance rates to carbapenems than the strains in 2016. Conclusions The bacterial isolates in 2017 pose serious threat to clinical antibiotic therapy. More attention should be paid to rational use of antimicrobial agents and infection control measures.

Antimicrobial resistance profile of clinical isolates in hospitals across China: report from the CHINET Surveillance Program, 2017 / 中国感染与化疗杂志

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.

Drug Resistance of Pathogens in Blood Culture Specimens in Shaanxi Antimicrobial Resistant Investigation Net from 2013 to 2015 / 现代检验医学杂志

Objective To explore the Gram-positive bacterial drug resistance in blood culture in 2013 to 2015 from the members of Antimicrobial Resistant Investigation Net of Shaanxi province,and guide the clinicians touse antimicrobial drugs rationally.Methods All the objective bacterial isolates were collected and identified susceptibility date by software WHONET 5.6.Results 8 824 Gran positive bacterial isolates and their antibacterial susceptibilitydata were collected.The top five populations of Gram-positive bacterial isolates were Staphylococcus epidermidis,Staphylococcus hominis,Staphylococcus haemolyticus,Staphylococcus aureus and Enterococcus feacium.The isolating rates of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase negative Staphylococcus(MRCNS) were 33.9 ～ 54.9％ and 72.1 ～88.6 ％ respectively.No vancomycin,Linezolid and teicoplanin resistant Staphylococcus isolates were found.There were 0.9 ～2％ E.faecium vancomycin-resistant isolates.Conclusion The composition of blood culture from 2013 to 2015 was not changed,The rate of MRSA and MRSE showed downward trend.But it was severe that the situation of bacterial drug resistance in blood culture in Shaanxi province.Should fully use bacterial drug resistance surveillance results for supervision and administration,and take effective measures for controlling the spread of resistant isolates.

Antimicrobial resistance in a class A tertiary hospital in Baise, Guangxi Province: 2015 surveillance report / 中国感染与化疗杂志

Objective? To?understand?the?distribution?and?antibiotic?resistance?profile?of?clinical?isolates?in?the?Affiliated?Hospital?of Youjiang Medical University during 2015. Methods The pathogenic microorganisms were isolated from inpatients from January to?December,?2015?in?the?Affiliated?Hospital?of?Youjiang?Medical?University.?Antimicrobial?susceptibility?testing?was?carried?out?according?to?a?unified?protocol?using?Kirby-Bauer?method?or?VITEK?2-Compact?systems.?The?results?were?interpreted?according?to CLSL breakpoints released in 2014, and analyzed by WHONET 5.6 software. Results A total of 4004 strains of bacteria were collected, including 1146 (28.6%) strains of gram-positive bacteria, and 2858 (71.4%) strains of gram-negative organisms. The?prevalence?of?MRSA?and?MRCNS?was?25.8?%?and?79.4?%,?respectively.?MRSA?and?MRCNS?strains?were?significantly?more?resistant to most antibiotics than MSSA and MSCNS except trimethoprim-sulfamethoxazole. Most of the S. pneumoniae isolates were from non-meningitis patients, showing high resistance rate to macrolides and tetracycline, but very low resistance rate to quinolones. Enterococcus isolates were mainly E. faecium and E. faecalis. More E. faecium were resistant to high-level gentamicin and high-level streptomycin than E. faecalis. E. faecium isolates were generally more resistant than E. faecalis to most of the antimicrobial agents tested except clindamycin and tetracyclines. But no gram-positive cocci were found resistant to vancomycin, linezolid or tigecycline. ESBLs-producing strains accounted for 53.1% of the E. coli strains and 28.5% of K. pneumoniae isolates. Enterobacteriaceae isolates were still very susceptible to carbapenems. E. coli isolates were more resistant to most of the antimicrobial agents tested than other Enterobacteriaceae except to piperacillin-tazobactam and carbapenems. Enterobacteriaceae showed higher resistance to trimethoprim-sulfamethoxazole than the other antibiotics tested. Majority of P. aeruginosa isolates were susceptible to all the antibiotics tested (<10% resistant). A. baumannii?strains?showed?significantly?higher?resistance rate than P. aeruginosa to all the antibiotics tested. Conclusions Most of the data in this report are consistent with the national?data?in?terms?of?antimicrobial?resistance?profile.?These?data?are?useful?for?rational?use?of?antibiotics.

Etiological and antibiotic resistance profile of bloodstream infections in 107 old patients / 中国感染与化疗杂志

Objective To investigate the etiological and antibiotic resistance profile in the old patients with bloodstream infection (BSI).Methods Microbiological and clinical data were collected and reviewed retrospectively for the patients with confirmed bloodstream infection and at least 65 years of age who were treated as inpatients in Tongling People′s Hospital from January to December 2015.Results A total of 107 strains of pathogen were isolated from the blood samples of 107 patients with bloodstream infections, of which community-acquired BSI accounted for 57.9 % (62/107), and hospital-acquired BSI 42.1 % (45/107). Gram negative bacilli accounted for 67.7 % in the pathogens of community-acquired BSI and gram positive cocci accounted for 55.5 % in the pathogens of hospital-acquired BSI. More male BSI patients were secondary to respiratory tract infection than female patients (P<0.001), while more female BSI patients were secondary to urinary tract infection than male patients (P<0.001). Of the 107 isolates, gram negative bacilli, gram positive cocci and fungi accounted for 55.1 % (59/107), 42.1 % (45/107) and 2.8 % (3/107), respectively. The top six pathogens were E. coli (30.9 %), coagulase negativeStaphylococcus (CNS) (20.6 %), S. aureus (10.3 %),K. pneumoniae (6.5 %),Enterococcusspp. (6.5 %) and Acinetobacter spp. (4.7 %). About 51.5 % of the E. coli isolates and 28.6 % of the K. pneumoniae isolates produced extended-spectrum β-lactamases (ESBLs).E. coli isolates showed low resistance rate (< 10 %) to amikacin,cefoxitin and piperacillin-tazobactam. No E. coli isolate was found resistant to carbapenem. About 14.3 % to 28.6 % of K. pneumoniae isolates were resistant to carbapenems. No tigecycline-resistant K. pneumoniae was found. The prevalence of MRSA and MRCNS was 36.4 % and 72.7 %, respectively. No staphylococcal isolates were found resistant to vancomycin, teicoplanin or linezolid. One strain of E. faecium was identified as resistant to vancomycin (VRE).Conclusions This surveillance data indicate that gram negative bacilli play an important role in the BSI of old patients. E. coli and CNS are the most common pathogens. We should pay more attention to the effect of gender and site of infection on the BSI in old patients.

CHINET surveillance of bacterial resistance across China: report of the results in 2016 / 中国感染与化疗杂志

Objective To investigate the susceptibility profile of clinical isolates collected from hospitals across China.Methods Twenty-six general hospitals and four 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 analyzed according to CLSI 2016 breakpoints.Results A total of 153 059 clinical isolates were collected from Junuary to December 2016,of which gram-negative organisms and gram-positive cocci accounted for 71.6％ and 28.4％,respectively.The overall prevalence of methicillin-resistant strains was 38.4％ in S.aureus (MRSA) and 77.6％ in coagulase negative staphylococcus (MRCNS),respectively.The resistance rates of methicillin-resistant strains to most of other antimicrobial agents were much higher than those of methicillin-susceptible strains.However,92.3％ of the MRSA strains were still sensitive to trimethoprim-sulfamethoxazole,while 86.5％ of the MRCNS strains were susceptible to rifampin.No staphylococcal strains were found resistant to vancomycin or teicoplanin.The resistance rates of E.faecalis strains to most drugs tested (except chloramphenicol) were much lower than those of E.faecium.A few strains of both species were resistant to vancomycin.Vancomycin resistant E.faecalis and E.faecium strains were mainly VanA,VanB or VanM type based on their phenotype or genotype.Regarding the non-meningitis S.pneumoniae strains,the prevalence of PSSP or PISP strains isolated from children was higher than that isolated in 2015,but the prevalence of PRSP strains decreased.However,the prevalence of PISP and PRSP strains isolated from adults was lower than that isolated in 2015.The prevalence of ESBLs-producing strains was 45.2％ in E.coli,25.2％ in Klebsiella spp.(K.pneumoniae and K.oxytoca) and 16.5％ in Proteus mirabilis isolates on average.ESBLs-producing Enterobacteriaceae strains were more resistant than non-ESBLs-producing strains in terms of antibiotic resistance rate.The strains of Enterobacteriaceae were still highly susceptible to carbapenems.Overall,less than 10％ of these strains were resistant to carbapenems.About 68.6％ and 71.4％ ofAcinetobacter spp.(A.baumannii accounts for 90.6％) strains were resistant to imipenem and meropenem,respectively.The prevalence of extensively-drug resistant strains in P.aeruginosa was higher than that in 2015.Conclusions Bacterial resistance to commonly used antibiotics is still on the rise.It is necessary to strengthen hospital infection control and management of clinical use of antimicrobial agents,and maintain good practice in surveillance of bacterial resistance.

Report of bacterial resistance surveillance in Zhujiang Hospital in 2015 / 中国感染与化疗杂志

Objective To investigate the susceptibility profile of clinical isolates in Zhujiang Hospital in 2015.Methods Susceptibility test was carried out using Kirby-Bauer method or automated systems.Results A total of 4 229 clinical isolates were isolated from January to December 2015,including 2 688 (63.6％) gram negative and 1 541 (36.4％) gram positive bacteria.Methicillin-resistant S.aureus (MRSA) and coagulase-negative Staphylococcus (MRCNS) accounted for 47.2％ and 76.4％,respectively.The methicillin-resistant strains have much higher resistance rates to beta-lactams and other antimicrobial agents than methicillin-susceptible strains.Majority (94.0％) of MRSA strains were susceptible to trimethoprim-sulfamethoxazole,and 83.1％ MRCNS strains were susceptible to rifampin.No staphylococcal isolates were found resistant to vancomycin,teicoplanin or linezolid.E.faecalis strains showed much lower resistance rate to most of the drugs tested (except chloramphenicol) than E.faecium.No enterococcal isolates were found resistant to vancomycin or teicoplanin.ESBLs were produced in 52.6％ of E.coli and 39.7％ of Klebsiella (K.pneumoniae and K.oxytoca) strains.ESBLs-producing Enterobacteriaceae strains had higher resistance rates to common antimicrobial agents than non-ESBLs-producing strain.Enterobacteriaceae isolates were highly susceptible to carbapenems,(＜4％ resistant).Acinetobacter spp.strains showed high resistance to imipenem (69.2％ resistant) and meropenem (71.2％ resistant).Conclusions The antibiotic resistance is still increasing in this hospital.The emerging multi-drug or pan-drug resistant strains pose a serious threat to clinical practice and implies the importance of strengthening infection control.

Surveillance of antibiotic resistance of clinical isolates in Shandong Provincial Hospital during 2016 / 中国感染与化疗杂志

Objective To investigate the antibiotic resistance of clinical isolates in Shandong Provincial Hospital during 2016.Method The antimicrobial susceptibility of isolates was tested by using VITEK 2-Compact system or disk diffusion method.All the data were analyzed by WHONET 5.6 software according to CLSI 2016 breakpoints.Results A total of 4 810 non-duplicate clinical strains were collected during 2016,of which gram-negative bacilli and gram-positive cocci accounted for 70.2％ and 29.8％,respectively.The most common specimen source was respiratory tract (38.1％),followed by skin and soft tissue (21.1％) and urine (17.5％).Escherichia coli was the most frequently isolated bacteria,followed by Staphylococcus aureus,Pseudomonas aeruginosa,Klebsiella and Enterococcus,accounting for 24.3％,10.2％,9.9％,9.8％ and 9.6％,respectively.The prevalence of ESBLs-positive E.coli and K.pneumoniae was 55.0％ and 37.9％,respectively.Carbapenem-resistant E.coli and K.pneumoniae accounted for 1.6％ and 4.2％,respectively.The percentage of P aeruginosa resistant to imipenem and meropenem was 24.3％ and 21.9％,respectively.More than 40％ of the A.baumannii strains were resistant to all the antibiotics tested except minocycline (33.2％).The prevalence of beta-lactamase positive strains was 70.1％ in H.influenzae and 97.5％ in M.catarrhalis.The prevalence of methicillin-resistant S.aureus (MRSA) was 31.4％.No staphylococcal strains were found resistant to vancomycin,teicoplanin or linezolid.E.faecium strains showed higher resistance rate to most antibiotics tested than E.faecalis.One strain of E.faecium was resistant to both vancomycin and teicoplanin.A total of 191 strains of S.pneumoniae were isolated,of which 143 (74.9％) isolates were from pediatric wards.None of the non-meningitis strains was resistant to penicillin.Other hemolytic Streptococcus strains were sensitive to penicillin,cephalosporins and vancomycin.Conclusions Bacterial resistance is still on rise.We should pay more attention to strengthening antimicrobial resistance surveillance and improving rational use of antimicrobial agents.

Surveillance of bacterial resistance at Children's Hospital of Chongqing Medical University in 2015 / 中国感染与化疗杂志

Objective To investigate the susceptibility and resistance profile of clinical isolates.Methods Clinical isolates were collected from Children's Hospital of Chongqing Medical University from January 1 to December 31,2015.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were analyzed according to CLSI 2015 breakpoints.Results A total of 13 109 clinical isolates were collected from January to December 2015,of which gram negative organisms and gram positive cocci accounted for 65.3 ％ (8 560/13 109) and 34.7 ％ (4 549/13 109),respectively.Methicillin resistant strains in S.aureus (MRSA) and coagulase negative Staphylococcus (MRCNS) accounted for 29.6 ％ and 67.1％,respectively.Most (93.1％) MRSA strains were still susceptible to trimethoprim-sulfamethoxazole,while 80.2 ％ of MRCNS strains were susceptible to rifampin.No staphylococcal strains were found resistant to vancomycin,teicoplanin or linezolid.The resistance rates of E.faecalis strains to most antibiotics tested (except tetracycline) were much lower than those of E.faecium.Some strains of both species were resistant to vancomycin.No E.faecalis or E.faecium strains were found resistant to vancomycin.The prevalence of ESBLs-producing strains was 55.7 ％ in E.coli and 43.5 ％ in Klebsiella (K.pneumoniae and K.oxytoca) and 11.6 ％ in Proteus mirabilis isolates.ESBLs-producing Enterobacteriaceae strains were more resistant than non-ESBLs-producing strains in terms of antibiotic resistance rates.Enterobacteriaceae strains were still highly susceptible to carbapenems.Overall,less than 16.0 ％ of these strains were resistant to carbapenems.About 10.5 ％ and 9.4 ％ of the A.baumannii strains were resistant to imipenem and meropenem,respectively.Compared to the data of year 2014,the prevalence of extensively-drug resistant P.aeruginosa and K.pneumoniae strains increased.Conclusions The antibiotic resistance of clinical bacterial isolates is growing.The emerging and increasing prevalence of multi-drug or pan-drug resistant strains poses a serious threat to clinical practice and implies the importance of strengthening infection control.

Surveillance of antibiotic resistance among the bacterial strains isolated from hospitals in Shanghai: results of 2016 / 中国感染与化疗杂志

Objective To investigate the resistance profile of clinical bacterial isolates to antibiotics in Shanghai during 2016.Methods Antimicobial susceptibility testing was carried out for the clinical isolates collected from 47 hospitals according to a unified protocol using Kirby-Bauer method or automated systems.The participating hospitals included 28 tertiary hospitals and 19 secondary hospitals across Shanghai.Results were analyzed according to CLSI 2016 breakpoints.Results A total of 122 548 clinical isolates were collected,including 35 522 (29.0％) strains of gram positive cocci and 87 026 (71.0％) strains of gram negative bacilli.Overall,28.9％ of the isolates were from secondary hospitals and 71.1％ from tertiary hospitals.Gram positive and gram negative isolates accounted for 25.8％ and 74.2％ in secondary hospitals,30.3％ and 69.7％ in tertiary hospitals,respectively.The overall prevalence of MRSA in Staphylococcus aureus was 48.7％ and 77.2％ of MRCNS in coagulase-negative Staphylococcus.The average prevalence of MRSA and MRCNS was 55.9％ and 73.3％ in secondary hospitals,45.9％ and 78.6％ in tertiary hospitals.No strains were found resistant to vancomycin in Staphylococcus.About 77.4％ of the 1 111 strains of non-meningitis S.pneumoniae isolated from children were penicillin-susceptible (PSSP),13.2％ were penicillin-intermediate (PISP) and 9.4％ were penicillinresistant (PRSP).The prevalence of PSSP,PISE and PRSP was 97.8％,2.2％,and 0 in secondary hospitals,76.5％,13.7％,and 9.8％ in tertiary hospitals.Of the 285 strains isolated from adults,94.0％,4.2％ and 1.8％ were PSSP,P1SP and PRSP,respectively.The prevalence of PSSP,PISP and PRSP among the isolates from adults was 93.7％,5.3％,and 1.0％ in secondary hospitals,94.2％,3.7％,and 2.1％ in tertiary hospitals.Overall,37 strains of vacomycin-resistant E.feacium (14 from secondary hospitals and 23 from tertiary hospitals) and 25 strains of vacomycin-resistant E.feacalis (all from tertiary hospitals) were identified.PCR and sequencing analysis indicated that most of these resistant strains were vanA type.The overall prevalence of ESBLs-producing srains was 52.2％ in E.coli,30.9％ in Klebsiella pneumoniae and 29.8％ in Proteus mirabilis.Specifically,the corresponding prevalence of such strains was 55.1％,33.6％ and 34.0％ in secondary hospitals,51.0％,29.7％ and 28.0％ in tertiary hospitals,respectively.Enterobacteriaceae strains were still highly susceptible to carbapenem antibiotics.Overall,8.9％ and 9.1％ of the Enterobacteriaceae strains were resistant to imipenem and meropenem,respectively.The figure was 6.6％ and 7.1％ in secondary hospitals,9.9％ and 10.0％ in tertiary hospitals.Extensively drug-resistant strains were identified in A.baumannii,K.pneumoniae,P.aeruginosa,and E.coli,specifically,223,63,10,and 4 strains in secondary hospitals;224,201,22,and 9 strains in tertiary hospitals.Conclusions Antibicotic resistance is still very serious in the common clinical strains,which poses a critical threat to healthcare facilities.This issue should be taken seriously and effective infection control measures must be put in place.

Surveillance of bacterial resistance in Shanghai Renji Hospital during the period from 2005 to 2015 / 中国感染与化疗杂志

Objective To investigate the antimicrobial resistance of clinical isolates from Renji Hospital,Shanghai Jiao Tong University School of Medicine during the period from 2005 to 2015.Methods Antimicrobial susceptibility testing was carried out according to Kirby-Bauer method.Results were analyzed according to CLSI 2015 breakpoints.Results A total of 55 155 nonduplicate clinical isolates were collected from 2005 to 2015.The top 5 most frequently isolated bacterial species were E.coli (15.0％),P.aeruginosa (14.0％),A.baumannii (11.9％),K.pneumoniae (11.8％) and S.aureus (10.2％).Gram positive cocci and gram negative organisms accounted for 35.8％ and 64.2％,respectively.The prevalence of methicillin-resistant strains in S.aureus (MRSA) and coagulase negative Staphylococcus (MRCNS) was 70.2％ (3 967/5 650) and 83.2％ (4 997/6 004).No staphylococcal strain was resistant to vancomycin,teicoplanin or linezolid.Fifteen strains of Enterococcus were found resistant to vancomycin.The average prevalence of ESBLs-producing strains was 70.4％ (5 843/8 300) in E.coli,53.5％ (3 500/6 539) in Klebsiella spp.and 44.1％ (557/1 263) in P mirabilis.A few carbapenemaseproducing K.pneumoniae strains were identified for the first time in 2012 with the prevalence of 0.6％ (4/656),and the prevalence hit high (30.1％,142/472) in 2015.The prevalence of carbapenemase-producing E.coli was 2.0％ (16/787) in 2015,and almost zero in the other years.The prevalence of extensively drug-resistant A.baumannii and P.aeruginosa was 39.1％ (2 566/6 556) and 4.0％ (308/7 704),respectively.Extensively drug-resistant strain was identified in 9 of the strains of 189 E.aerogenes isolates.Conclusions Bacterial resistance is still on the rise,which poses a major challenge to clinical antimicrobial therapy,especially the multi-drug resistant and extensively drug resistant bacteria.

Surveillance of antimicrobial resistance in the bacterial strains isolated from hospitals in Dongguan, Guangdong Province: 2015 report / 中国感染与化疗杂志

Objective To survey the resistance profile of clinical isolates to antibiotics across the hospitals in Dongguan,Guangdong Province during 2015.Methods Kirby-Bauer method or automated system was used to test the susceptibility of clinical isolates to selected antimicrobial agents.Results were analyzed according to CLSI 2015 breakpoints.The susceptibility data were analyzed using WHONET 5.6 software.Results A total of 29 665 strains of microorganisms were isolated,of which gram positive cocci accounted for 32.1％ (9 509/29 665) and gram negative bacilli accounted for 67.9％ (20 156/29 665),respectively.The prevalence of methicillinresistant Staphylococcus was 23.3％ (705/3 024) in S.aureus and 43.6％ (1 054/2 419) in coagulase-negative Staphylococcus.No vancomycin-resistant staphylococcal strain was found.ESBLs-producing strains accounted for 36.4％ (2 554/7 020) in E.coli and 24.5％(792/3 227) in Klebsiella isolates.The prevalence of carbapenem-resistant Enterobacteriaceae was 0.2％ (30/13 077).The prevalence of carbapenem-resistant Pseudomonas aeruginosa (CRPA) and carbapenem-resistant Acinetobacter baumannii (CRAB) was 16.0％ (500/3 116) and 53.9％ (827/1 533),respectively.The prevalence of penicillin-resistant S.pneumoniae (PRSP) strains was 10.1％ (142/1 404).Beta-lactamase was produced in 30.6％ (276/902) of the H.influenzae strains.The prevalence of vancomycin-resistant Enterococcus (VRE) strains was 0.7％ (10/1 441).Conclusions Periodic surveillance of antimicrobial resistance is valuable for rational antimicrobial therapy,formulation of treatment guidelines and infection control and prevention measures,as well as preventing the spread of drug-resistant strains.