ABSTRACT
Objective:To evaluate the performance of an artificial intelligent (AI)-based automated digital cell morphology analyzer (hereinafter referred as AI morphology analyzer) in detecting peripheral white blood cells (WBCs).Methods:A multi-center study. 1. A total of 3010 venous blood samples were collected from 11 tertiary hospitals nationwide, and 14 types of WBCs were analyzed with the AI morphology analyzers. The pre-classification results were compared with the post-classification results reviewed by senior morphological experts in evaluate the accuracy, sensitivity, specificity, and agreement of the AI morphology analyzers on the WBC pre-classification. 2. 400 blood samples (no less than 50% of the samples with abnormal WBCs after pre-classification and manual review) were selected from 3 010 samples, and the morphologists conducted manual microscopic examinations to differentiate different types of WBCs. The correlation between the post-classification and the manual microscopic examination results was analyzed. 3. Blood samples of patients diagnosed with lymphoma, acute lymphoblastic leukemia, acute myeloid leukemia, myelodysplastic syndrome, or myeloproliferative neoplasms were selected from the 3 010 blood samples. The performance of the AI morphology analyzers in these five hematological malignancies was evaluated by comparing the pre-classification and post-classification results. Cohen′s kappa test was used to analyze the consistency of WBC pre-classification and expert audit results, and Passing-Bablock regression analysis was used for comparison test, and accuracy, sensitivity, specificity, and agreement were calculated according to the formula.Results:1. AI morphology analyzers can pre-classify 14 types of WBCs and nucleated red blood cells. Compared with the post-classification results reviewed by senior morphological experts, the pre-classification accuracy of total WBCs reached 97.97%, of which the pre-classification accuracies of normal WBCs and abnormal WBCs were more than 96% and 87%, respectively. 2. The post-classification results reviewed by senior morphological experts correlated well with the manual differential results for all types of WBCs and nucleated red blood cells (neutrophils, lymphocytes, monocytes, eosinophils, basophils, immature granulocytes, blast cells, nucleated erythrocytes and malignant cells r>0.90 respectively, reactive lymphocytes r=0.85). With reference, the positive smear of abnormal cell types defined by The International Consensus Group for Hematology, the AI morphology analyzer has the similar screening ability for abnormal WBC samples as the manual microscopic examination. 3. For the blood samples with malignant hematologic diseases, the AI morphology analyzers showed accuracies higher than 84% on blast cells pre-classification, and the sensitivities were higher than 94%. In acute myeloid leukemia, the sensitivity of abnormal promyelocytes pre-classification exceeded 95%. Conclusion:The AI morphology analyzer showed high pre-classification accuracies and sensitivities on all types of leukocytes in peripheral blood when comparing with the post-classification results reviewed by experts. The post-classification results also showed a good correlation with the manual differential results. The AI morphology analyzer provides an efficient adjunctive white blood cell detection method for screening malignant hematological diseases.
ABSTRACT
Objective:To explore the predictive efficacy of prothrombin time (PT) with regarding for the severity and prognosis of septic patients, along with comparing with other routine coagulation parameters.Methods:A retrospective analysis was conducted. The clinical data of 302 septic patients who were admitted to the intensive care unit (ICU) of Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology from January 1 to December 31 in 2019 were enrolled. Demographic and basic clinical data were collected. Laboratory data, including PT, activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (FIB), D-dimer, fibrin (fibrinogen) degradation product (FDP), antithrombin (AT), platelet count (PLT) at ICU admission were recorded, and sequential organ failure assessment (SOFA) score, acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) score within 24 hours of admission to ICU were also collected. What's more, some major clinical events, such as septic shock, disseminated intravascular coagulation (DIC), etc. during ICU stay were also monitored. A follow-up 28 days observation of prognosis was performed. The patients were divided into the septic shock group and the non-septic shock group according to the occurrence of septic shock, and they were divided into the survival group and the non-survival group according to the 28-day prognosis. The differences in terms of above parameters between each two groups were compared. Spearman correlation method was used to analyze the correlation between routine coagulation parameters and SOFA score or APACHEⅡ score. Receiver operator characteristic curve (ROC curve) was plotted to determine the predictive efficacy of each routine coagulation parameter with regarding to predict septic shock and 28-day mortality. Based on the cut-off value of PT, the septic patients were divided into two risk stratifications, and then the major clinical and end point outcome were compared. Kaplan-Meier survival curve analysis was applied to investigate the difference of the 28-day cumulated survival rate based on the different risk stratifications of PT level. Finally, multivariate Logistic regression analysis was used to explore whether prolonged PT level was an independent risk factor for septic shock and 28-day mortality.Results:The 302 patients were all enrolled, including 120 patients with septic shock and 182 patients without. Seventy-five patients died within 28 days, while 227 survived. Comparing with the non-septic shock group or the survival group, the septic shock group or the non-survival group patients both had longer PT, APTT and TT, higher D-dimer, FDP and lower PLT, FIB and AT. Correlation analysis revealed that PT and PLT were better correlated with SOFA score ( r values were 0.503 and -0.524, both P < 0.01), and PT was better correlated with APACHEⅡ score ( r = 0.407, P < 0.01). ROC curve analysis showed that PT had the most powerful predictive efficacy for septic shock and 28-day mortality. The area under the ROC curve (AUC) and 95% confidence interval (95% CI) were 0.831 (0.783-0.879) and 0.739 (0.674-0.805), respectively. The cut-off value were 16.8 s and 16.3 s, respectively, with the sensitivity of 64.2%, 72.0% and the specificity of 89.0%, 70.9%, respectively. Risk stratification based on PT level revealed that the patients with PT > 16.5 s ( n = 103) had higher rate of 28-day mortality, incidence of septic shock and DIC, and score of SOFA and APACHEⅡ comparing to those with PT ≤ 16.5 s ( n = 199). Kaplan-Meier survival curve analysis showed that the 28-day cumulative survival rate was significantly lower in the patients with PT > 16.5 s than those with PT ≤ 16.5 s (52.43% vs. 86.93%; Log-Rank test: χ 2 = 49.428, P < 0.001). Multivariate Logistic regression analysis revealed that PT > 16.5 s was an independent risk factor both for septic shock and 28-day mortality [model 1 (enrolled SOFA score): odds ratio ( OR) and 95% CI were 6.003 (3.040-11.855), 4.842 (2.114-11.089); model 2 (enrolled APACHEⅡ score): OR and 95% CI were 7.675 (4.007-14.702), 5.160 (2.258-11.793)]. Conclusions:Compared with other routine coagulation parameters, PT has the potential best predictive value for evaluating the severity of sepsis and the prognosis. When a patient is diagnosed with sepsis and has a result of PT longer than 16.5 s at ICU admission, the patient may have a higher risk of progression to septic shock and short-term death.
ABSTRACT
Objective:To retrospectively analyze the clinical characteristics and drug resistance among COVID-19 patients with bacterial and fungal infections.Methods:Clinical data of COVID-19 patients whose blood, urine, sputum and alveolar lavage fluid samples were positive for bacteria and fungi were collected in Tongji Hospital from February 10 to March 31, 2020. WHONET5.6 software was used to analyze drug susceptibility test results.Results:A total of 95 COVID-19 patients positive for pathogenic bacteria were enrolled and among them, 23 were non-critical patients and 72 were critical patients. The main symptoms in these patients included fever, cough with sputum, fatigue and dyspnea. Male and female critical patients accounted for 63.89% and 36.11%, respectively. Most of the patients with bacterial and fungal infections were critical type, accounting for 23.61%. The mortality rates of non-critical and critical patients were 13.04% and 61.11%, respectively. A total of 179 strains of pathogenic bacteria were isolated. The positive rate of Escherichia coli in non-critical patients was 37.50%, which was higher than that in critical patients. However, the positive rates of Acinetobacter baumannii and Klebsiella pneumoniae in critical patients were both 29.87%, higher than those in non-critical patients. There was no significant difference in the positive rate of gram-positive bacteria or fungi between non-critical and critical patients. It was noteworthy that the positive rate of Candida parapsilosis in blood samples of critical patients was relatively high, reaching 36.40%. Drug susceptibility test results showed that no carbapenem-resistant Escherichia coli stains were detected and 60.87% of Klebsiella pneumoniae strains were resistant to carbapenems. Acinetobacter baumannii strains were 100% resistant to three antimicrobial drugs. Methicillin-resistant Staphylococcus aureus strains accounted for 71.43%, but no vancomycin-resistant gram-positive cocci were found. Conclusions:Critical COVID-19 patients were mostly male and prone to multiple bacterial and fungal infections. The mortality of critical patients was higher than that of non-critical patients. Critical COVID-19 was often complicated by hospital acquired infections caused by bacteria including Acinetobacter baumannii and Klebsiella pneumoniae with high drug resistance.
ABSTRACT
Objective:To monitor the susceptibility of common used antimicrobial agents against nosocomial Gram-negative bacilli in 2018 across China.Methods:Prospective collection of Gram-negative bacilli from 13 teaching hospitals nationwide from January to December 2018. The minimal inhibitory concentration (MICs) of antibiotics such as meropenem was determined by agar dilution methods and broth microdilution methods. Interpretation of results using the Clinical and Laboratory Standards Institute(CLSI) 2019 M100S (29th Edition) standard. Data were analyzed by using WHONET-5.6 software.Results:A total of 1 214 non-repetitive Gram-negative bacilli were collected, accounting for 96.7% (1 174/1 214) of blood and sterile body fluid samples. The activity of antimicrobial agents against 871 strains of Enterobacteriaceae was as follows in descending order of susceptible rate: amikacin (93.2%, 812/871), meropenem (92.0%, 801/871), ertapenem (88.9%, 774/871), imipenem (88.4%, 770/871), piperacillin-tazobactam (84.0%, 732/871), cefoperazone-sulbactam (83.1%, 724/871), cefepime (71.4%, 622/871), minocyline (68.9%, 600/871), ceftazidime (66.9%, 583/871), levofloxacin (54.4%, 474/871).The resistance rates of Escherichia coli to the third generation cephalosporins were 61.5% (155/252) (ceftriaxone) and 60.7% (153/252) (cefotaxime), respectively. The resistance rates of Klebsiella pneumoniae to the third generation cephalosporins were 56.6% (126/222) (ceftriaxone) and 57.9% (129/222) (cefotaxime), respectively. The incidence of extended-spectrum β lactamase (ESBLs) positive E. coli and K. pneumoniae was 50.2% (127/252) and 18.2% (40/222), respectively. Over 95% of all the ESBLs positive strains were susceptible to imipenem and meropenem. The incidence of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae was 2.8% (7/252) and 20.4% (45/222), respectively. For Enterobacter cloacae, Klebsiella aerogenes, Citrobacter freundii, the most susceptible agent were tigecycline (96.3%-100%), followed by amikacin (94.9%-97.1%), meropenem (89.8%-96.6%)and imipenem (89.8%-94.9%).The susceptibility of Proteus mirabilis, Morganella morganii and Serratia marcescens to meropenem and amikacin was over 90%.A total of 67 strains of carbapenems resistant enterobacteriaceae(CRE) were detected. Modified carbapenem inactivation method showed, 45 strains were serine carbapenemase and 20 were metalloenzymes. The susceptibility of Pseudomonas aeruginosa to meropenem and imipenem were 73.2% (112/153) and 66.0% (101/153), respectively. Acinobacter baumannii has the highest sensitivity to colistin (100%, 163/163), followed by tigecycline (87.1%, 142/163).Compared with other sources of infection, specimens of bloodstream infections were less resistant to Klebsiella pneumoniae (17.6%, 27/153 vs 21.7%, 15/69) and Acinetobacter baumannii (68.3%, 71/104 vs 71.2%, 42/59). Escherichia coli (2.5%,4/198 vs 0%,0/54) and Pseudomonas aeruginosa (37%, 33/89 vs 18.8%, 12/64) have a high proportion of carbapenem resistance. Conclusions:Carbapenems still maintain high antibacterial activity against Enterobacteriaceae bacteria, especially strains producing only ESBLs. Carbapenem-resistant Klebsiella pneumoniae should be given sufficient attention. Carbapenemase is the most important drug resistance mechanism of carbapenem-resistant Enterobacteriaceae in China.
ABSTRACT
Objective To learn the distribution, epidemiology and antimicrobial susceptibility of diarrheagenic Escherichia coli (DEC) isolated from patients with acute diarrhea among children less than 5 years old. Methods Totally 684 stool samples collected from Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology between August 1, 2015 and September 30, 2016 were tested by culture and identified the common pathogens. PCR was applied to detect the virulence genes of DEC. Meanwhile, serotyping of enteropathogenic E. coli (EPEC) was performed by slide agglutination tests for all the isolates of EPEC. An antimicrobial sensitivity test was performed using the agar dilution method. Results A total of 149 (21.7％) enteric bacteria pathogens were isolated from 684 specimens. DEC was found in 54 cases, ranked 2nd among the pathogenic bacteria. DEC tended to occur in summer/autumn periods. EPEC was the most frequent DEC genotype, accounted for 50％ (27/54). Among EPEC, atypical EPEC was dominant, accounted for 77.8％ (21/27) and typical EPEC only accounted for 22.2％ (6/27). Followed by enteroaggregative E. coli 20.4％(11/54), enterotoxigenic E. coli 14.8％(8/54), enteroinvasive E. coli and Shiga toxin-producing E. coli 3.7％(2/54), 7.4％(4/54) cases were co-infected with more than one DEC genotypes. About 17/18 of suspicious DEC isolates can get the same genotypes by commercial multiplex PCR kit and single PCR test. Among the 27 EPEC strains, only 11(40.7％) strains can be detected by the slide agglutination serotyping method. More than 50％ (27/54) of DEC isolates were resistant to conventional first-line antibiotics (ampicillin, trimethoprim-sulfamethoxazole) and cefazolin, cefuroxime, cefotaxime, but relatively low resistance to cefoxitin, amikacin, piperacillin/tazobactam, imipenem and meropenem. However, there was still a 9.2％ (5/54) resistance rate to carbapenems. Conclusions DEC strains exhibited a high frequency of resistance to many antibiotics. Empirical antimicrobial therapy of severe DEC infection faces the challenge from the high resistance to ampicillin, trimethoprim-sulfamethoxazole. Even worse, some strains were resistant to relatively efficient drugs imipenem and meropenem. It is necessary to strengthen the epidemiological survey and antimicrobial resistance of DEC.
ABSTRACT
Objective To investigatethe relationship between urinary catecholamine levels and type Ⅱ diabetic nephropathy and neuropathy. Methods Allsubjects were collected fromTongji Hospital, Tongji Medical College, Huazhong University of Science and Technology,and were divided into two groups:type Ⅱ diabetic patients (For 24 h urine, n=130, aged 27-81 years old, 75 men, 55 female; for random urine, n=115, aged 27-77 years old, 75 men, 40 female) and healthy control (For 24 h urine, n=118, aged 27-76 years old, 67 men, 51 female; for random urine, n=93, aged 25-74 years old, 57 men, 36 female).Based on the results of urinary albumin excretion, type Ⅱ diabetic patients were prospectively divided into two independent groups: patients with nephropathy (For 24 h urine, n=37; for random urine, n=32) and patients without nephropathy (For 24 h urine, n=32; for random urine, n=35). According to questionnaires, quantitative sensory testing and autonomic function test, type Ⅱ diabetic patients were divided into two different groups: patients with neuropathy (For 24 h urine, n=31; for random urine, n=23) and patients without neuropathy (For 24 h urine, n=30; for random urine, n=35). Urinary catecholamines(CAs) levels, including epinephrine (E), norepinephrine (NE), dopamine (DA) and total catecholamines (total CAs) levels, were measured using liquid chromatography tandem mass spectrometry (LC-MS / MS). The CAs levels in different groups have been discussed. The results were analyzed using χ2 test, independent t test and Mann-Whitney non-parametric test. Results Type Ⅱ diabetic patients with nephropathy show lower E (0.74±0.24) μg/24 h,NE(9.22±4.02) μg/24 h,DA(64.77±21.68) μg/24 h and total CAs(74.72±25.65) μg/24 h in 24-hour urine in comparison with the group without nephropathy(For E, 4.23±0.50 μg/24 h, U=10, P<0.001; for NE, (32.31±1.74) μg/24 h, t=-2.72, P=0.011; for DA, (219.58±27.51) μg/24 h, t=-2.88, P=0.007;fro CAs, (256.02±30.65) μg/24 h, t=-3.02, P=0.005) and the differences were statistically significant (P<0.05). The differences of NE, DA and total CAs between type Ⅱ diabetic patients with nephropathyand without nephropathy were statistically significant in random urine(P<0.05). Conclusion These results suggested that urine CAs levels in diabetic patients with nephropathy is lower than that in patients without nephropathy, which may be related to the occurrence and development of diabetic nephropathy.
ABSTRACT
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.
ABSTRACT
Objective To investigate antimicrobial resistance among nosocomial gram-negative bacilli in 2016 across China.Methods About 1 394 consecutive and non-repetitive gram-negative bacilli were isolated from 14 teaching hospitals from March to August in 2016 across China.All of these isolates were sent to the central laboratory for reidentification and susceptibility testing.The minimal inhibitory concentration(MICs)of meropenem and other antibacterial agents were determined by agar dilution method.The data were analyzed by using WHONET-5.6 software.Results The activity of antimicrobial agents against Enterobacteriaceae was as follows in descending order of susceptible rate: meropenem (95.2%,891/936), amikacin (94.6%,885/936), ertapenem (92.1%,862/936), piperacillin/tazobactam (88.1%,825/936), imipenem (88.0%,823/936), cefoperazone-sulbactam (83.1%,778/936), cefepime (72.2%,676/936), cefiazidime (72.2%,676/936), levofloxacin(68.8%,644/936), ciprofloxacin (63.2%,592/936), minocyline (62.9%,589/936), cefiriaxone (54.9%,514/936), cefotaxime (54.0%,505/936), cefoxitin (44.3%,415/936).The sensitivities of E.coli to carbapenems, amikacin, piperacillin-tazobactam, polymyxin B and cefoperazone-sulbactam were over 80%.The more sensitive antibiotic to Klebsiella pneumoniae was polymyxin B (99.0%), followed by amikacin (84.9%), meropenem (84.4%) and imipenem (82.0%).The prevalence of extended-spectrum β-lactamase was 62.8%(137/218)in Escherichia coli and 28.3%(58/205)in Klebsiella pneumonia.The activity of antimicrobial agents against E.cloacae, E.aerogenes and Citrobacter freundii was as follows in descending order of susceptible rate: meropenem (97.0%-98.5%), amikacin (95.8%-98.3%), imipenem (94.5%-97.5%), polymyxin B (96.4%-100%), cefoperazone-sulbactam (76.5%-90.0%), ertapenem (73.3%-90.1%), piperacillin/tazobactam (82.4%-88.3%).The most active agents against Pseudomonas aeruginosa were polymyxinB (100%), followed by amikacin (89.3%) and ciprofloxacin (82.4%).The most active agents against Acinetobacter baumannii were polymyxinB (100%).The sensitivities of Acinetobacter baumannii to meropenem, imipenem, minocycline and cefoperazone-sulbactam were 20.3%(39/202), 19.3%(41/202), 66.3%(134/202) and 24.8%(50/202), respectively.Conclusions Carbapenems remain high sensitive against Enterobacteriaceae.Controlling carbapenem resistant Klebsiella pneumoniae is urgent.Drug antimicrobial resistance in A.baumanni is a still serious problem.
ABSTRACT
Objective To investigate the incidence of prozone phenomenon of rapid plasma reagin (RPR) test in syphilis serolog-ic testing and its correlation with the intensity of chemiluminescent microparticle immunoassay (CMIA) results.Methods A total of 101493 patients in our hospital from January 2014 to December 2015 were performed syphilis serologic testing by CMIA ,RPR and treponema pallidum particle agglutination (TPPA).The incidence rate of prozone phenomenon in RPR testing was evaluated.Its in-fluencing factors were investigated by using the Logistic regression.Results Among 101493 serum samples ,2180 cases were posi-tive by CMIA and 767 cases were positive by RPR ,the incidence rate of prozone phenomenon was 3.3% (26/767)in RPR.The Lo-gistic regression results indicated that the incidence of prozone phenomenon was significantly correlated with CMIA S /CO values and RPR titer ,but had no correlation with sex ,age and seasonality.Conclusion Although the incidence of prozone phenomenon is low in syphilis serologic testing ,but it is enough important.The patients with higher S/CO value in CMIA test have a higher inci-dence rate of RPR prozone phenomenon.
ABSTRACT
Objective To explore the distribution and antimicrobial resistance of pathogens causing lower respiratory tract infection in patients, and provide basis for rational choice of antimicrobial agents in clinic.Methods All bronchoalveolar lavage fluid specimens in a hospital from January 1, 2013 to December 31, 2014 were performed culture, antimicrobial susceptibility testing of isolated strains was performed with Kirby-Bauer method.Results A total of 999 strains were isolated from 7 702 bronchoalveolar lavage fluid specimens, 398 (5.17%), 326 (4.23%), and 275(3.57%) strains were bacteria, fungus, and Mycobacterium respectively.The main bacteria were Pseudomonas aeruginosa(P.aeruginosa, n=97), Acinetobacter baumannii(A.baumannii, n=87), Klebsiella pneumoniae(K.pneumoniae, n=62), Staphylococcus aureus(S.aureus, n=44), and Haemophilus influenzae (n=28);the main fungi were Candida albicans (n=161), Aspergillus fumigatus (n=41), and Aspergillus flavus(n=38);the main Mycobacterium were Mycobacterium tuberculosis(n=271).Antimicrobial susceptibility testing results showed that resistance rates of P.aeruginosa to the commonly used antimicrobial agents (except ticarcillin/clavulanic acid and levofloxacin) were all80.00%, but to the other commonly used antimicrobial agents were 36.84%-60.53%.Among 62 strains of K.pneumoniae, 20 were extended-spectrum β-lactamases(ESBLs)-producing strains.Antimicrobial resistance rates of ESBLs-producing strains were obviously higher than non-ESBLs-producing strains.Among 44 S.aureus strains, 26 were methicillin-resistant S.aureus (MRSA), resistance rate of S.aureus to penicillin was 97.73%, to vancomycin, teicoplanin, and linezolid were all 0, to the other antimicrobial agents were 9.09%-61.36%.Conclusion Bacteria is the major pathogen causing lower respiratory tract infection in hospitalized patients, but fungus and Mycobacterium can not be ignored.Resistance rates of P.aeruginosa to commonly used antimicrobial agents is relatively low, but resistance of A.baumannii is more serious.
ABSTRACT
Objective To evaluate the changing pattern of antibiotic resistance inKlebsiella strains isolated from the patients in 19 hospitals across China based on the data from CHINET Antimicrobial Resistance Surveillance Program during the period from 2005 through 2014.Methods Kirby-Bauer disk diffusion and automated susceptibility testing methods were used to test the susceptibility ofKlebsiella isolates to the commonly used antibiotics. The results were interpreted according to the criteria of the Clinical and Laboratory Standards Institute (CLSI) Performance Standards for Antimicrobial Susceptibility Testing (CLSI-2014).Results A total of 61 406Klebsiella strains were identified between 2005 and 2014, includingK. pneumoniae (56 281 strains), K. oxytoca(4 779),Klebsiella pneumoniae subsp.Ozaenae (300) and otherKlebsiella species (46). Most (89.0%, 54 664/61 406) of theKlebsiella strains were isolated from inpatients, and 60.0% (36 835/61 406) were from respiratory tract speciems. About 16.7% (10 248/61 406) of the strains were isolated from pediatric patients aged 0-17 years and 83.3% (51 158/61 406) from adult patients. The prevalence ofKlebsiella spp. increased with time from 10.1% in 2005 to 14.3% in 2014. Based on the surveillance data during the 10-year period, we found a marked increase of resistance to imipenem (2.9% to 10.5%) and meropenem (2.8% to 13.4%) inKlebsiella spp. The prevalence of ESBLs-producing isolates inK. pneumoniae andK. oxytoca decreased from 39.0% in 2005 to 30.1% in 2014. The resistance to amikacin, ceftazidime, ciprolfoxacin, pipracillin-tazobactam and cefoperazone-sulbactam was on decline. The resistance rate to cefotaxime remained high about 49.5%. Carbapenem resistantance was identiifed in 5 796 (9.4%) of the isolates, including 5 492 strains ofK. pneumoniae and 280 strains ofK. oxytoca. Overall, 4 740 (7.8%) strains were identiifed as extensively-drug resistant (XDR), including 4 520 strains ofK. pneumoniae and 202 strains ofK. oxytoca. The carbapenem-resistant strains showed high (>60%) resistance rate to majority of the antimicrobial agents tested, but relatively low resistance to tigecycline (16.8%), amikacin (54.4%), and trimethoprim-sulfamethoxazole (55.5%).Conclusions During the 10-year period from 2005 through 2014, carbapenem resistance amongKlebsiella isolates has increased dramatically in the hospitals across China. The level of resistance to other antibiotics remains stable.
ABSTRACT
Objective To investigate the distribution and antibiotic resistance proifle of clinicalEnterobacter isolates using the data from CHINET during the period from 2005 through 2014.Methods A total of 20 558 clinical strains ofEnterobacter spp. were collected from 2005 to 2014 in CHINET Antimicrobial Resistance Surveillance Program. Antimicrobial susceptibility testing was performed with Kirby-Bauer or minimum inhibitory concentration method. The results were analyzed according to CLSI 2014 breakpoints.ResultsEnterobacter cloacae andEnterobacter aerogenes accounted for 71.1% (14 617/20558) and 20.1% (4 129/20 558) of all theEnterobacterisolates, respectively. The proportion ofEnterobacter spp. increased with time from 3.5% in 2005 to 4.3% in 2014. The main source of the isolates was respiratory tract, accounting for 55.2% (11 358/20 558). More than 90% of theEnterobacterisolates were resistant to cefazolin and cefoxitin, but less than 30% of the strains were resistant to cefepime, piperacillin-tazobactam, cefoperazone-sulbactam, amikacin, gentamicin, ciprolfoxacin, meropenem, imipenem and ertapenem. TheEnterobacterisolates showed a trend of declining resistance to most antibiotics except ertapenem and meropenem. The resistance proifle ofEnterobacterisolates varied with departments where they were isolated. The strains from ICU and Department of Surgery were relatively more resistant to antibiotics. The prevalence of multi-drug resistant (MDR) strains was decreasing, but the prevalence of carbapenem-resistantEnterobacter (CRE, resistant to any of imipenem, meropenem or ertapenem) was increasing. The MDR and CRE strains were primarily isolated from ICU and Department of Surgery. At least 30% of the MDREnterobacter strains were resistant to any of the antimicrobial agents tested except meropenem, imipenem and ertapenem and at least 35% of the CRE strains were resistant to any of the antimicrobial agents tested except amikacin and ciprolfoxacin.Conclusions TheEnterobacter isolates in CHINET Antimicrobial Resistance Surveillance Program showed decreasing resistance to most of the antimicrobial agents tested since 2011, but the prevalence of CRE strains increased progressively. Effective measures should be carried out to prevent the spread of CRE strains in hospitals.
ABSTRACT
Objective To understand the changing resistance proifle ofProteus,Serratia,Citrobacter,Morganella andProvidencia in hospitals across China according to the data from CHINET Antimicrobial Resistance Surveillance Program 2005-2014.Methods Antimicrobial susceptibility was tested by using Kirby-Bauer method or automatic minimum inhibitory concentration determination according to a uniifed protocol.Results A total of 21 663 clinical isolates were collected from January 2005 to December 2014. The proportion ofProteus andSerratia isolates increased with time from 1.41% in 2005 to 2.09% in 2014, and from 0.99% in 2005 to 1.28% in 2014 among all the isolates. No change was found for the proportion ofCitrobacter,Morganella, orProvidencia. Less than 10% of theProteus isolates were resistant to cefoperazone-sulbactam, piperacillin-tazobactam, ceftazidime, cefoxitin, amikacin and tigecycline. Less than 10% of theSerratia isolates were resistant to cefoperazone-sulbactam, piperacillin-tazobactam, amikacin and tigecycline. Less than 20% of theCitrobacter isolates were resistant to cefoperazone-sulbactam, piperacillin-tazobactam, cefepime, amikacin and tigecycline. Less than 10% of theMorganella isolates were resistant to cefoperazone-sulbactam, piperacillin-tazobactam, cefepime, amikacin and tigecycline. Less than 20% of theProvidencia isolates were resistant to cefoperazone-sulbactam, piperacillin-tazobactam, cefepime, cefoxitin and tigecycline.Conclusions The antibiotic resistance ofProteus,Serratia, Citrobacter,Morganella andProvidencia isolates in hospitals across China is growing during the period from 2005 to 2014. Strengthening infection control and rational antibiotic use are effective to slow the growth of drug resistance.
ABSTRACT
Objective To investigate the distribution and changing resistance proifle ofSalmonella isolates in hospitals across China during the period from January 2005 to December 2014.Methods Seventeen general hospitals and two children’s hospitals were involved in this program. Antimicrobial susceptibility testing was carried out by means of a unified protocol using Kirby-Bauer method or MIC determination. The results were analyzed according to CLSI 2014 breakpoints.Results The proportion ofSalmonella isolates increased with time from 0.2% in 2005 to 0.7% in 2014. A total of 3 478Salmonella strains were collected from 19 hospitals. The proportion ofSalmonella typhimurium andSalmonella enteritidis was 27.4% and 24.4%, respectively. During the 10-year period, theSalmonella strains showed highest resistance rate to ampicillin (33.3%-64.8%), but low resistance to cefoperazone-sulbactam (0-5.3%) and ciprofloxacin (2.4%-14.3%).S. typhimurium showed higher resistance rate thanS. typhi,S. paratyphi andS. enteritidis. About 76.8% and 50.5% ofS. typhimurium were resistant to ampicillin and trimethoprim-sulfamethoxazole. The average prevalence of multi-drug resistantSalmonellawas 3.9% in the ten-year period, the highest (7.5%) was in 2005, the lowest (1.5%) in 2013.Conclusions During the period from 2004 to 2015, majority of theSalmonella isolates in hospitals across China wasS. typhimurium andS. enteritidis. Ampicillin and trimethoprim-sulfamethoxazole are no longer appropriate for empirical treatment ofS. typhimurium infection due to high resistance rate.Salmonella isolates are relatively more susceptible to third-generation cephalosporins and quinolones. Ongoing monitoring is necessary to identify multi-drug resistant strains ofSalmonella.
ABSTRACT
Objective To analyze the resistance proifle of bacterial strains isolated from geriatric patients in 17 hospitals across China from 2005 to 2014.Methods A total of 17 representative general hospitals were involved in this program. Bacterial susceptibility testing was carried out by means of a uniifed protocol using Kirby-Bauer method and MIC determination. The results were analyzed according to CLSI 2014 breakpoints.Results The proportion of the strains isolated from geriatric patients among all the clinical isolates increased with time from 30.0% in 2005 to 32.7% in 2014. A total of 159 888 clinical isolates were collected from geriatric patient during the period from 2005 to 2014, about 33.1% of the whole patient population. Gram negative organisms and gram positive cocci accounted for 77.1% (123 229/159 888) and 22.9% (36 659/159 888), respectively. Majority (92.8%, 148 376/159 888) of the isolates were from inpatients and more than half (55.2%, 88 201/159 888) of the isolates were from sputum or other respiratory tract specimens. Methicillin-resistant strains inS. aureus (MRSA) and coagulase negativeStaphylococcus (MRCNS) accounted for an average of 67.1% and 75.9%, respectively. The resistance rates of methicillin-resistant strains to β-lactams and other antimicrobial agents were much higher than those of methicillin-susceptible strains. No staphylococcal strains were found resistant to vancomycin, teicoplanin or linezolid. Some strains ofE. faecalis (0.4%) andE. faecium (4.6%) were resistant to vancomycin, which was higher than average national level (0.3%, 3.2%). Vancomycin-resistant strains ofE. faecalisandE. faecium were mainly VanA type and VanB type based on their phenotype. The prevalence of penicillin-susceptibleS. pneumoniae strains was 78.2%, slightly lower than the 95.0% in Chinese adults in year 2014. The prevalence of ESBLs-producing strains was 67.5% inE. coli, 40.4% inKlebsiella (K. pneumoniae andK. oxytoca) and 34.3% inProteus mirabilis isolates on average. The strains ofEnterobacteriaceae were still highly susceptible to carbapenems (<10% resistant), followed by amikacin and the beta-lactam and beta-lactamase inhibitor combinations. Overall, 35.9% and 33.0% of theP. aeruginosa strains were resistant to imipenem and meropenem. More than 50% of theA. baumannii strains were resistant to imipenem and meropenem. The prevalence of extensively drug-resistant (XDR)P. aeruginosa (4.0%-1.8%) was higher than the average national level (2.1%-1.6%). The prevalence of XDR A. baumannii (19.2%-15.5%) and XDREnterobacteriaceae (0.1%-1.0%) was lower than the average national level (21.4%-19.7% and 0.3%-3.2%).Conclusions The proportion of clinical isolates from geriatric patients is different from average national level at the same period. The isolates from geriatric patients are more likely from inpatients, respiratory tract specimens and more likely non-fermentative gram-negative bacilli compared to average national level. The proportion of fastidious bacteria andEnterobacteriaceae species is generally lower than average national level. MRSA, VRE, ESBLs-producing strains and XDRP. aeruginosa are more prevalent in geriatric patients than in general Chinese patient population. This study suggests that surveillance of antimicrobial resistance for the clinical isolates from geriatric patients is very important for rational antimicrobial therapy.
ABSTRACT
Objective To investigate the susceptibility and resistance of clinical isolates from hospitals in several regions of China .Methods Fifteen general hospitals and two 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 2014 breakpoints .Results A total of 78 955 clinical isolates were collected from January to December 2014 ,of which gram negative organisms and gram positive cocci accounted for 72 .6% and 27 .4% ,respectively . Methicillin‐resistant strains in S .aureus(MRSA)and coagulase negative Staphylococcus(MRCNS)accounted for an average of 44 .6% and 83 .0 % ,respectively .The resistance rates of methicillin‐resistant strains to β‐lactams and other antimicrobial agents were much higher than those of methicillin‐susceptible strains .However ,92 .0% of MRSA strains were still susceptible to trimethoprim‐sulfamethoxazole ,while 85 .6% of MRCNS strains were susceptible to rifampin .No staphylococcal strains were found resistant to vancomycin ,teicoplanin or linezolid .In Enterococcus spp .,the resistance rates of E .f aecalis strains to most tested drugs (except chloramphenicol) were much lower than those of E . f aecium .Some strains of both species were resistant to vancomycin .Vancomycin resistant strains of E . f aecalis and E . f aecium were mainly V anA ,V anB or V anM type based on their phenotype or genotype .Regarding non‐meningitis S .pneumoniae strains ,the prevalence of penicillin‐susceptible S .pneumoniae strains isolated from both adults and children were higher than those isolated in 2013 ,but the prevalence of penicillin‐intermediate S . pneumoniae or penicillin‐resistant S . pneumoniae strains decreased . The prevalence of ESBLs producingstrainswas55.8% in E.coliand29.9% in Klebsiellaspp.(K.pneumoniaeand K.oxytoca)and24.0% in Proteus mirabilis isolates on average . ESBLs‐producing Enterobacteriaceae strains were more resistant than non‐ESBLs‐producing strains in terms of antibiotic resistance rates . The strains of Enterobacteriaceae were still highly susceptible to carbapenems .Overall less than 10 % of these strains were resistant to carbapenems . About 62 .4% and 66 .7% of Acinetobacter spp .(A .baumannii accounts for 93 .0 % ) strains were resistant to imipenem and meropenem ,respectively . Compared with the data of year 2013 ,extensively‐drug resistant strains in K . pneumoniae and A .baumannii increased . Conclusions The antibiotic resistance of clinical bacterial isolates is growing .The disseminated multi‐drug or pan‐drug resistant strains in a special region poses a serious threat to clinical practice and implies the importance of strengthening infection control .
ABSTRACT
Objective To investigate distribution and drug resistance of pathogenic bacteria in lower respitatory tract infection. Methods Distribution and drug resistance of pathogenic bacteria in lower respitatory tract infection of patients in ICU and non-ICU of our hospital during 2013 were retrospectivly analyzed. The pathogens were identified by manual methods routinely and those difficult to be identified were analyzed by using the VITEK-2-COMPACT instrument. Antimicrobial susceptibility of these isolates were tested by Kirby-Bauey methods routinely. Results In total, 956 strains were isolated from lower respitatory tract infection of patients in ICU, including 231 strains of gram-positive cocci (24. 2%), 680 strains of gram-negative bacteria (71. 1%), 45 strains of fungi (4. 7%). In patients of non-ICU, 4 464 strains were isolated, including 1 090 strains of gram-positive cocci (24. 4%), 3 226 strains of gram-negative bacteria (72. 3%), and 148 strains of fungi (3. 3%). Staphylococcus aureus, acinetobacter baumannii and pseudomonas aeruginosa were the most frequent isolates in patients of ICU and non-ICU. The overall prevalence of methicillin resistant staphylococcus aureus (MRSA) in staphylococcus aureus was 87. 0%in ICU and 74. 0% in non-ICU. MSSA was sensitive to the most antibiotics ( more than 80. 0% of the strains were sensitive to common antibiotics) except penicillin, erythromycin and clindamycin. MRSA was sensitive to trimethoprim-sulfamethoxazole and fosfomycin (more than 75. 0% of the strains were sensitive to the antibiotics) except for vancomycin, teicoplanin and linezolid. Acinetobacter baumannii was more resistant to the antibiotics (less than 40. 0% of the strains were susceptible to the antibiotics). Pseudomonas aeruginosa from ICU was more resistant to the antibiotics ( less than 50. 0% of the strains were sensitive to the antibiotics) than that from non-ICU. Stenotrophomonas maltophilia was sensitive to trimethoprim-sulfamethoxazole, levofloxacin and minocycline (more than 80. 0% of the strains were sensitive to the antibiotics). Escherichia coli and Klebsiella pneumoniae were sensitive to Piperacillin-tazobactam and Amikacin except for meropenem and imipenem ( more than 80. 0% of the strains were sensitive to the antibiotics) . Conclusion Gram-negative bacteria was the most frequent isolate in lower respitatory tract infection of our hospital during 2013. Staphylococcus aureus, acinetobacter baumannii and pseudomonas aeruginosa were the most frequent isolates in ICU and non-ICU. Resistance to the antibiotics was more common in ICU than in non-ICU. Antibiotics should be prescribed according to bacterial resistance results reasonably in order to prevent the spread of drug-resistant strains.
ABSTRACT
Objective Toinvestigateantimicrobialresistanceamonggram-positivecocciinChinain 2013.Methods Retrospectivestudy.FromJune2013toDecember2013,1663consecutiveandnon-repetitive gram-positive cocci were collected from 15 teaching hospitals. The minimal inhibitory concentration ( MIC) of antibacterial agents was determined by agar dilution method. A retrospective study was conducted on rates of resistance to antimicrobial agents. The prevalence of penicillin-resistant Streptococcus pneumoniae ( PRSP) between children and adult patients and the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) between elder group and younger adult patients were compared using chi-square test. Results The prevalence of PRSP in children below 3 years old ( 72. 9%, 51/70 ) was higher than adult patients (55. 2%, 106/192) (χ2 =6. 653,P<0. 05). About 94. 9%(261/275) and (92. 7%,255/275) of S. pneumonia were resistant to erythromycin and clindamycin. All S. pneumoniae strains were susceptible to teicoplanin, vancomycin, linezolid, tigecycline and daptomycin. Penicillin still showed very high activity against Streptococcus spp. β-Hemolytic group. More than 60% of Streptococcus spp.β-Hemolytic group were resistant to erythromycin, clindamycin and tetracyclines. The prevalence of MRSA and methicillin-resistant coagulase-negative Staphylococci(MRCoNS) was 39. 7%(229/576) and 80. 6%(224/278), respectively. The MRSA prevalence ranged from 24. 2% to 70. 0% in different regions. About 52. 6%( 100/190 ) of Staphylococcus aureus from respiratory tract specimens, 38. 5%(40/104)of Staphylococcus aureus from blood samples, and 29. 7%(58/195) of Staphylococcus aureus from wound and pus were resistant to methicillin. The prevalence of MRSA in elder group ( 48. 6%, 84/173 ) was higher than that in younger adult patients (35. 7%, 144/403)(χ2 =8. 322,P <0. 05). The susceptibility rates of MRSA to chloramphenicol and trimethoprim/sulfamethoxazole were 86. 4% ( 244/228 ) and 94. 7% ( 237/228 ) , respectively. Susceptibility rates to gentamycin, erythromycin, clindamycin, tetracyclines, rifampicin and quinolones were ranged from 15. 8% to 59. 6%. All Staphylococci isolates were susceptible to teicoplanin, vancomycin, linezolid, daptomycin and tigecycline. All Enterococcus isolates were susceptible to daptomycin and tigecycline. All E. faecalis ( 158/158 ) and 96. 4% ( 133/138 ) of E. faecium were susceptible to teicoplanin. About 98. 0% ( 150/153 ) of E. faecalis and 97. 1% ( 145/138 ) of E. faecium were susceptible to linezoild. About 45. 8% (70/153) of E. faecalis and 60. 9% (84/138) of E. faecium were resistant to gentamycin with a high concentration. The susceptibility of E. faecalis to all the antibiotics tested exceptchloramphenicolandtetracyclinewashigherthanthatofE.faecium.Conclusions Basedon different age groups and regions, the resistance rates of Gram-positive cocci are different. Teicoplanin, vancomycin, tigecycline, daptomycin, linezolid and tedizolid showed very high activity against Gram-positive cocci. (Chin J Lab Med,2015,38:373-381)
ABSTRACT
Objective To investigate the distribution,variability and antibiotic resistance of the pathogen sisolated from bloodstream infections.Methods The bacterial strains were routinely isolated from blood samples and identified.Brucella trains were identified by PCR and gene sequencing.Antimicrobial susceptibility were routinely tested for these isolates.Results A total of 2 152 strains,excluding coagulase negative Staphylococcus,were isolated from blood specimens during the 5-year period from 2009 through 2013.Gram-positive cocci,gram-negative bacilli and fungi accounted for 35.3% (761/2 152), 57.7% (1 242/2 152)and 6.9% (149/2 152),respectively.The top three gram-positive bacteria were S.aureus,E.faecium and E.faecalis.E.coli,K.pneumoniae,P .aeruginosa,A.baumannii,and Brucella were the most frequently isolated gram-negative bacteria.In 2009,only one Brucella melitensis was isolated,but increased to 50 in 2013 (7.1%),including one strain of Brucella suis .The prevalence of MRSA was 54.1% in S.aureus.No staphylococcal isolate was found resistant to vancomycin or linezolid.More than 60% of the E.faecalis isolates still showed low resistance (70%)except glycopeptides and linezolid.E. coli and K.pneumoniae isolates displayed low resistance rate ( were still the most common pathogens in blood stream infections.Attention should be paid to the increasing prevalence of Brucella in blood stream infections.Various levels of antibiotic resistance are found in the pathogens of blood stream infections.Antibiotics should be prescribed reasonably according to local susceptibility testing data.
ABSTRACT
Objective To explore the inhibitory effect of 24 pseudomonas aeruginosa(PA) on pathogenic fungi ,such as candida albicans ,candida tropicalis ,candida glabrata ,candida parapsilosis ,candida krusei ,mucous spore bacterium (MSB) etc .Methods 24 PA isolates were collected from clinical specimens and identified by Gram′s stain ,oxidase production and the API 20NE system(bi-oMerieux ,France) .Cross-streaking method and sterilizing filter paper-disk method and co-cultured method were applied to observe the inhibitory effect of PA .Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) analyzed the difference of bacte-rial proteins of PA .Results The results showed that some strains of 24 PA had strong inhibitory effect against pathogenic fungi , some strain had partial effect and others had no effect .Co-cultured test showed that PA could inhibit the growth of fungal hyphae . SDS-PAGE displayed the significant difference in secretive proteins between the PA strains which had strong effect and no effect . Conclusion PA have inhibitory effect upon common pathogenic fungi and and this might be related to inhibit fungal hyphae forma-tion ,various protein secretion and inhibit the growth of fungi .