Nationwide surveillance of the antimicrobial susceptibility of Chlamydia trachomatis from male urethritis in Japan: Comparison with the first surveillance report

The Urogenital Sub-committee and the Surveillance Committee of the Japanese Society of Chemotherapy, The Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology conducted the second nationwide surveillance of the antimicrobial susceptibility of Chlamydia trachomatis. In this second surveillance study, clinical urethral discharge specimens were collected from patients with urethritis in 26 hospitals and clinics from May 2016 to July 2017. Based on serial cultures, the minimum inhibitory concentration (MIC) could be determined for 41 isolates; the MICs (MIC₉₀) of ciprofloxacin, levofloxacin, tosufloxacin, sitafloxacin, doxycycline, minocycline, erythromycin, clarithromycin, azithromycin and solithromycin were 2 μg/ml (2 μg/ml), 1 μg/ml (0.5 μg/ml), 0.25 μg/ml (0.25 μg/ml), 0.125 μg/ml (0.063 μg/ml), 0.125 μg/ml (0.125 μg/ml), 0.25 μg/ml (0.25 μg/ml), 0.031 μg/ml (0.031 μg/ml), 0.25 μg/ml (0.125 μg/ml), and 0.016 μg/ml (0.008 μg/ml), respectively. In summary, this surveillance project did not identify any strains resistant to fluoroquinolone, tetracycline, or macrolide agents in Japan. In addition, the MIC of solithromycin was favorable and lower than that of other antimicrobial agents. However, the MIC of azithromycin had a slightly higher value than that reported in the first surveillance report, though this might be within the acceptable margin of error. Therefore, the susceptibility of azithromycin, especially, should be monitored henceforth.     

菌尿症标本的直接药敏试验

目的　探讨菌尿症的快速药敏试验方法。方法　涂片镜检每个油镜视野平均菌数≥ 2的标本疑为菌尿症 ,直接进行纸片扩散法药敏试验 ,孵育 16～ 18h后观察结果 ,同时进行标本定量培养和菌落计数 ,得到的纯培养菌株按常规纸片扩散法做比较试验。结果　共检测了 16 6例革兰阴性菌和 5 1例革兰阳性菌菌尿标本 ,直接药敏试验与NCCLS推荐的纸片扩散法的结果比较差异无显著性 (P >0 .0 5 )。结论　对于菌尿标本 ,直接药敏试验是一种快速、简便、经济的方法 ,可在 2 4h内报告初步的药敏结果 ,以供临床早期用药参考     

Microbial genomics and antimicrobial susceptibility testing

Introduction: Antimicrobial susceptibility testing is key in modern clinical microbiology. With pandemic emergence of (multi-)antibiotic resistance, methods to detect and quantify resistance of clinically important bacterial species are imperative. Historically, antimicrobial susceptibility testing (AST) was mostly performed using methods relying on bacterial growth. Such methods may be time-consuming and more rapid alternatives have been actively sought for.

Areas covered: Among the new AST methods there are many that focus on detection of causal resistance genes and/or gene mutations. The approaches most used are based on nucleic acid amplification and, more recently, high-throughput (next generation) sequencing of amplified targets and complete microbial genomes. The authors provide a review of PCR-mediated and genomic AST methods used for human and veterinary pathogens and show where these approaches work well or may become difficult to interpret.

Expert commentary: Microbial genome sequencing will play an important role in the field of AST, but there remain issues to be resolved. These include the development of user friendly data analysis, reducing the duration and cost of sequencing and comprehensiveness of the databases. In addition, clinical evaluation studies need to be performed involving real-life patients.     

Nationwide surveillance of the antimicrobial susceptibility of Neisseria gonorrhoeae from male urethritis in Japan

Neisseria gonorrhoeae is one of the most important pathogens causing sexually transmitted infection, and strains that are resistant to several antimicrobials are increasing. To investigate the trends of antimicrobial susceptibility among N. gonorrhoeae strains isolated from male patients with urethritis, a Japanese surveillance committee conducted the first nationwide surveillance. The urethral discharge was collected from male patients with urethritis at 51 medical facilities from April 2009 to October 2010. Of the 156 specimens, 83 N. gonorrhoeae strains were tested for susceptibility to 18 antimicrobial agents. The prevalence of β-lactamase-producing strains and chromosomally mediated resistant strains were 7.2 % and 16.5 %, respectively. None of the strains was resistant to ceftriaxone, but the minimum inhibitory concentration (MIC) of ceftriaxone for 7 strains (8.4 %) was 0.125 μg/ml. One strain was resistant to cefixime (MIC 0.5 μg/ml). The MICs of fluoroquinolones, such as ciprofloxacin, levofloxacin, and tosufloxacin, showed a bimodal distribution. The MIC of sitafloxacin was lower than those of the three fluoroquinolones listed here, and it was found that the antimicrobial activity of sitafloxacin was stronger than that of the fluoroquinolones. The MIC of azithromycin in 2 strains was 2 μg/ml, but no high-level resistance to macrolides was detected.     

半自动细菌分析专家系统在细菌药敏试验中的应用

目的为了解半自动细菌分析（ATB）专家系统在临床应用情况,对近一年来的药敏报告进行分析。方法全部细菌用ATB—expression半自动细菌分析仪鉴定到种,药敏试验采用ATB配套的药敏卡,并接受ATB专家系统的建议及更正或补充试验采用纸片扩散法。结果专家系统对来自临床的715株细菌的药敏结果进行监控,其中166株（23．2％）细菌药敏结果得到纠正。从213株大肠埃希菌、肺炎克雷伯菌和产酸克雷伯菌中检测出43株产超广谱β-内酰胺酶（ESBLs）菌,其中30株经纸片确证法证实阳性。ATB专家系统还从75株葡萄球菌中检测出59株耐甲氧西林葡萄球菌（MRS）,比原药敏结果增加了4株,但经纸片法证实仍漏检了4株苯唑西林低耐药株。结论通过ATB专家系统的监控,有效减少了药敏结果的错误,使其更趋于准确。但药敏结果还存在一些问题,需经有经验的人员审核。     

半自动细菌分析专家系统在细菌药敏试验中的应用

目的为了解半自动细菌分析(ATB)专家系统在临床应用情况,对近一年来的药敏报告进行分析。方法全部细菌用ATB-expression半自动细菌分析仪鉴定到种,药敏试验采用ATB配套的药敏卡,并接受ATB专家系统的建议及更正或补充试验采用纸片扩散法。结果专家系统对来自临床的715株细菌的药敏结果进行监控,其中166株(23.2%)细菌药敏结果得到纠正。从213株大肠埃希菌、肺炎克雷伯菌和产酸克雷伯菌中检测出43株产超广谱β-内酰胺酶(ESBLs)菌,其中30株经纸片确证法证实阳性。ATB专家系统还从75株葡萄球菌中检测出59株耐甲氧西林葡萄球菌(MRS),比原药敏结果增加了4株,但经纸片法证实仍漏检了4株苯唑西林低耐药株。结论通过ATB专家系统的监控,有效减少了药敏结果的错误,使其更趋于准确。但药敏结果还存在一些问题,需经有经验的人员审核。     

支原体487株药敏试验测定

目的 对泌尿生殖系感染患者行支原体检测及药敏分析以指导临床合理用药。方法 应用法国生物梅里埃公司IST试剂盒作支原体培养鉴定及药敏试验。结果 983例患者中分离到支原体487株，标本阳性率为49．5％，其中解脲脲原体（Uu）阳性率占74．7％，人型支原体（Mh）阳性率占18．1％，Uu＋Mh混合型阳性率占7．2％，药敏结果显示，支原体对多西环素最为敏感（98．1％），但对环丙沙星敏感度最低（17．3％）。结论 多西环素、交沙霉素、克拉霉素可作为目前治疗泌尿生殖系支原体感染的抗生素。     

粘液型铜绿假单胞菌药敏试验不同时间段结果分析

目的探讨产粘液型铜绿假单胞菌(Pseudomonasaexuginosa,PA)药敏试验(K-B法)结果的报告时机。方法对所分离出的11株产粘液型的PA进行体外药敏试验(K-B法)和环丙沙星、舒普深的MIC测定,且记录不同时间段(24h、48h、72h)的结果。然后将此菌进行转种数代,使其粘液消失,再进行上述操作。并将上述两次结果进行对比分析。结果产粘液型PA24h抑菌环直径的毫米数与48h、72h后的结果有显著性差异(P<0.05)。48h、72h的结果与转种后、粘液消失的PA24h、48h、72h的结果无显著性差异(P>0.05)。环丙沙星和舒普深的MIC的测定结果与K-B法的结果相符。结论产粘液型的PA的体外药敏试验(K-B法)结果应该尽量在48小时后报告。     

Development of a rapid assay methodology for antimicrobial susceptibility testing of Staphylococcus aureus

Development of a new phenotypic technique for rapid antimicrobial susceptibility testing (AST) of methicillin-resistant Staphylococcus aureus is presented. The new technique combines bacterial culturing and specific immunometric detection in a single separation-free process. The technique uses dry chemistry reagents and the recently developed two-photon excitation detection technology, which allows online detection of bacterium-specific growth. The performance of the new technique was evaluated by monitoring the growth of S. aureus reference strains and determining their susceptibility to oxacillin. In the direct analysis of clinical specimens, method specificity and tolerance to interferences caused by other bacteria present in the sample are pivotal. Other bacteria can compete with the bacteria of interest for nutrients, for example. Specificity and tolerance were studied against Staphylococcus epidermidis reference strains. The results suggest that the new technique could allow rapid AST directly from clinical samples within 6 to 8 h. Such a rapid and simple testing methodology would be a valuable tool in clinical microbiology because it would shorten the turnaround times of microbiologic analyses. Advantages of the new approach in relation to conventional methods are discussed.     

香港和北京两地血标本中革兰阴性杆菌的耐药性比较

目的 比较香港和北京两地血培养中革兰阴性菌的耐药性。方法 对1998—2003年从北京协和医院（n=530）和香港威尔斯亲王医院（n=2913）分离出非重复的血培养菌株，两地分别采用纸片扩散法和微量肉汤稀释法测其对亚胺培南，头孢他啶，头孢吡肟等13种抗菌药的敏感度。结果 香港（1471株）和北京（213株）的大肠埃希菌对阿米卡星、头孢他啶、头孢吡肟的耐药率范围分别为0．6％～5．0％和7．5％～23．5％。对庆大霉素、头孢呋辛、头孢噻肟、头孢曲松和环丙沙星的耐药率范围分别为12．6％～28．4%．4%和29．4％～68．4％。两地的克雷伯菌属（香港586株，北京70株）对哌拉西林-三唑巴坦和头孢他啶的耐药率分别为3．3％～11．3％和4．3％～17．7％。对阿米卡星、庆大霉素、头孢噻肟和头孢曲松的耐药率范围分别为15％～10．1％和5．8％～27．1％。上述菌株及香港的330株包括肠杆菌属、柠檬酸杆菌属和沙雷菌属（ECS菌）都对亚胺培南和美罗培南敏感，而北京65株ECS群菌有4．6％耐药。ECS群菌对头孢吡肟耐药率分别为8．8％和14％。其他β内酰胺类对该菌群耐药率为28．4％～96％。香港伤寒沙门菌对所测试抗菌药敏感，而北京的菌株对氨苄西林和哌拉西林耐药率为9．1％～18．2％。香港不动杆菌属和铜绿假单胞菌对亚胺培南和美罗培南的耐药率低于10％，但北京两者对亚胺培南的耐药率分别为13．6%～15．3％和8．8%～30．8％。结论 北京血培养中分离的革兰阴性杆菌对大多数抗菌药的耐药率高于香港。为两地革兰阴性菌败血症的经验治疗提供了有价值的参考信息。     

泌尿生殖道标本解脲脲原体和人型支原体检测及抗菌药物敏感性试验结果分析

目的 了解泌尿生殖道标本解脲脲原体和人型支原体对常用抗菌药物敏感性,为临床抗菌药物选择提供客观依据.方法 采用商品化的支原体培养及药敏试验试剂盒,对2016—2018年连续3年同济大学附属上海市第一妇婴保健院泌尿生殖道标本进行支原体检测及药敏测定.结果 3年间共采集泌尿生殖道标本35006份,12572份(35.9％)...     

Prediction of the persistence of Mycoplasma genitalium after antimicrobial chemotherapy by quantification of leukocytes in first-void urine from patients with non-gonococcal urethritis

Mycoplasma genitalium is regarded as another pathogen of male non-gonococcal urethritis (NGU). Failure to eradicate this mycoplasma is associated with persistent or recurrent NGU, but this mycoplasma is not routinely examined in clinical practice. In cases of M. genitalium-positive NGU, therefore, some criteria are needed to assess the success or failure of antimicrobial chemotherapy other than microbiological outcomes. We enrolled 49 men with M. genitalium-positive non-chlamydial NGU. At successive visits after treatment, we inquired about their symptoms, observed their urethral meatus for urethral discharge, and examined their first-void urine (FVU) for quantification of leukocytes and for the persistence of M. genitalium. M. genitalium was eradicated in 34 patients after treatment, whereas the mycoplasma persisted in 15. Urethritis symptoms and urethral discharges were not found to be predictors of the persistence of M. genitalium up to the 25th day after the start of treatment. Leukocyte counts in FVU from the patients with persistence of M. genitalium were significantly higher than those from the patients with eradication of the mycoplasma. Leukocyte counts of 10 leukocytes/μl or more between the 18th and 24th day after the start of treatment were most significantly associated with the persistence of M. genitalium. Quantification of leukocytes in FVU would appear to be crucial to judge the outcome of treatment in patients with non-chlamydial NGU and could be helpful to predict the persistence of M. genitalium after treatment when M. genitalium is not routinely examined in clinical specimens in clinical practice.     

Trends in serotypes and antimicrobial susceptibility of group B streptococci isolated in Korea

Studies of group B streptococci (GBS) have been limited in Korea, despite the necessity for such studies because of the increase in serious adult infections, the emergence of new serotypes, and the increase of resistance to certain antibiotics. In this study, trends in serotypes of GBS isolated in Korea were compared to determine any changes and emergence of new types, while antimicrobial susceptibility was tested and compared with that of group A streptococci (GAS). It was found that the most frequent infections caused by GBS were of the urinary tract, but other severe infections also occurred not only in newborns but also in adults. The prevalent serotypes were still Ia, Ib, and III, while new serotypes, VI and VIII, also emerged. GBS were susceptible to β-lactam antibiotics, but were much less so than GAS. The resistance rates to erythromycin and tetracycline were much higher than those in other countries, suggesting that these antibiotics are no longer very useful in Korea for the treatment of GBS infections. Received: November 22, 1999 / Accepted: January 27, 2000     

流式细胞术用于念珠菌快速药敏试验的研究

目的探讨应用流式细胞术(FCM)进行念珠菌快速药敏试验的方法及其应用价值。方法应用FCM检测氟康唑(FCZ)对念珠菌的抗菌活性,药物作用时间3 h后,用碘化丙啶(PI)染色,分别检测10株念珠菌阴性对照管和M IC药物浓度作用管的平均荧光强度(MFI),计算两者比值,据此,设定流式细胞药敏试验(FCST)检测M IC的判断值,并根据该判断值对16株临床菌株同时进行常规药敏和FCST双盲测定。结果10株念珠菌测得的MFI比值为2.03,CV为6.9%;将MFI大于阴性对照管2倍(增加100%)的最低药物浓度定义为该菌的M IC;16株临床菌株中,有15株念珠菌两种方法测得M IC值相差在1个倍比稀释度以内,两者差异无统计学意义(P>0.05)。结论FCST与常规药敏试验结果有很好的一致性,并且具有快速、敏感、准确、便于自动化等优势。     

社区获得性尿路感染菌群分布及耐药性分析

目的调查本地区社区获得性尿路感染(CAI)患者的菌群分布及耐药情况,促进临床合理选用抗菌药物。方法参照临床检验操作规程留取患者的中段尿进行培养、鉴定,药敏试验采用纸片扩散法。结果分离CAI病原菌263株,其中排名第1位的是大肠埃希菌,占64.3%,第2位的是肠球菌,占12.5%。大肠埃希菌的药敏结果显示对青霉素类、氟喹诺酮类抗生素的耐药率较高。结论本地区CAI的菌群分布不断发生变迁,细菌的耐药率有升高趋势。     

Epidemiological investigation and antimicrobial susceptibility analysis of Ureaplasma and Mycoplasma hominis in a teaching hospital in Shenyang,China

ObjectivesThe aim of this study was to estimate the prevalence and antimicrobial susceptibility of Ureaplasma urealyticum and Mycoplasma hominis in a comprehensive teaching hospital Shenyang, China over the past 4 years.MethodsA total of 1448 individuals with urogenital symptoms underwent mycoplasma testing between April 2016 and March 2020. Detection, identification and antimicrobial susceptibility testing were carried out using Mycoplasma ID/AST kits.ResultsThe total infection rate of genital mycoplasmas was 37.5% (543/1448 cases) with an observed increase over the past 4 years. The positive rates of all three detected infections, as well as overall infection rate, were significantly higher in females than in males (P < 0.05). A higher positive rate of infection was observed in females aged 25–29 (60.5%), and in the 15–19 years age group (57.7%). The changes observed among all age groups of females were statistically significantly different (P < 0.001). The positive rates of U. urealyticum and M. hominis co-infection among the four seasons during which the survey was carried out were also observed to be statistically different (P = 0.01). More than 70% of U. urealyticum isolates were found to be resistant to ciprofloxacin, and more than 80% of M. hominis isolates were resistant to erythromycin, roxithromycin, azithromycin and clarithromycin. Josamycin, doxycycline and minocycline were most effective against U. urealyticum and M. hominis.ConclusionsResults of this study found increasing rates of U. urealyticum and M. hominis infection over the past 4 years, particularly among younger age groups. U. urealyticum/Mycoplasma hominis screening among younger age cohorts are therefore strongly recommend to preventing the spread of pathogens. Monitoring antimicrobial resistance is important for preventing transmission of resistant strains of infection and for the management of antibiotics.     

Nationwide surveillance of bacterial pathogens isolated from children conducted by the surveillance committee of Japanese Society of Chemotherapy,the Japanese Association for Infectious Diseases,and the Japanese Society for Clinical Microbiology in 2017: General overview of pathogenic antimicrobial susceptibility

A nationwide surveillance of the antimicrobial susceptibility of pediatric patients to bacterial pathogens was conducted by Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in Japan in 2017. The isolates were collected from 18 medical facilities between March 2017 and May 2018 by the three societies. Antimicrobial susceptibility testing was conducted at the central laboratory (Infection Control Research Center, Kitasato University, Tokyo) according to the methods recommended by the Clinical Laboratory Standards Institute. Susceptibility testing was evaluated in 926 strains (331 Streptococcus pneumoniae, 360 Haemophilus influenzae, 216 Moraxella catarrhalis, 5 Streptococcus agalactiae, and 14 Escherichia coli). The ratio of penicillin-resistant S. pneumoniae was 0% based on CLSI M100-ED29 criteria. However, three meropenem or tosufloxacin resistant S. pneumoniae isolates were obtained. Among H. influenzae, 13.1% of them were found to be β-lactamase-producing ampicillin resistant strains, while 20.8% were β-lactamase non-producing ampicillin-resistant strains. No capsular type b strains were detected. In M. catarrhalis, 99.5% of the isolates were β-lactamase-producing strains. All S. agalactiae and E. coli strains were isolated from sterile body sites (blood or cerebrospinal fluid). The ratio of penicillin-resistant S. agalactiae was 0%, while that of extended spectrum β-lactamase-producing E. coli was 14.3%.     

Antimicrobial susceptibility and penicillin-binding protein 1 and 2 mutations in Neisseria gonorrhoeae isolated from male urethritis in Sapporo, Japan

The spread of antimicrobial-resistant Neisseria gonorrhoeae worldwide is a critical issue in the control of sexually transmitted infections. The purpose of this study was to clarify recent trends in the susceptibility of N. gonorrhoeae to various antimicrobial agents and to compare these data with our previous data. Minimum inhibitory concentrations (MICs) of various antimicrobial agents were determined in N. gonorrhoeae strains clinically isolated from male gonococcal urethritis. In addition, amino acid sequencing of penicillin-binding protein (PBP) 2, encoded by the penA gene, was analyzed so that genetic analysis of mosaic PBP 2 could clarify the susceptibility of the strains to cefixime and other cephalosporins. The susceptibility rate for ceftriaxone, cefodizime, and spectinomycin, agents whose use is recommended by the guideline of the Japanese Society of Sexually Transmitted Infections (JSSTI), was 100 %. The susceptibility rates of the strains to penicillin G and ciprofloxacin were lower than those in previous reports. Mosaic PBP 2 structures were detected in 51.9 % of the strains and the MICs of the strains with the mosaic PBP 2 to cefixime were much higher than those of the strains without the mosaic PBP 2. In the clinical situation, the treatment regimen recommended by the JSSTI remains appropriate; however, the susceptibility to cephalosporins should be intensively surveyed because strains with mosaic PBP 2 were commonly detected.     

Novel strategies for rapid identification and susceptibility testing of MRSA

ABSTRACT

Introduction

Methicillin-resistant Staphylococcus aureus (MRSA) is associated with adverse clinical outcomes and increased morbidity, mortality, length of hospital stay, and health-care costs. Rapid diagnosis of MRSA infections has been associated with positive impact on clinical outcomes.