Antimicrobial susceptibility and serotype distribution of Streptococcus pneumoniae isolated from patients with community-acquired pneumonia and molecular analysis of multidrug-resistant serotype 19F and 23F strains in Japan

A nationwide study was undertaken to determine the susceptibility to penicillin and serotypes of Streptococcus pneumoniae in Japan. S. pneumoniae was isolated from 114 adult patients with community-acquired pneumonia over 22 months at 20 hospitals and medical centres in different regions in Japan. All but five isolates were from sputum. Forty-eight isolates (42.1%) were susceptible, 40 (35.1%) showed intermediate resistance (MIC, 0.12-1.0 microg/ml) and 26 (22.8%) were resistant (MIC, >or=2.0 microg/ml) to penicillin G. All isolates were susceptible to ceftriaxone (breakpoint 1 microg/ml), imipenem (4 microg/ml) and vancomycin (4 microg/ml). Most were resistant to erythromycin, clarithromycin and azithromycin; only two were resistant to levofloxacin. Differences were found in the distribution of serotypes among isolates showing susceptibility to penicillin (predominant types 3, 6B, and 19F), intermediate resistance (6B, 14, 19F, and 23F) and full resistance (19F and 23F). PFGE typing showed that 14 of the 25 strains of serotype 19F had a single DNA profile, pattern A, a pattern closely similar to that of the Taiwan multidrug-resistant 19F clone. Twelve pattern A strains were not susceptible to penicillin but carried the macrolide resistance gene mef(A). The DNA profiles of the 15 strains of 23F were also heterogeneous but six were highly similar (pattern b) yet distinct from the Spanish multidrug-resistant 23F clone although possibly related to the Taiwan multidrug-resistant 23F clone. The pattern b strains were not susceptible to penicillin and also harboured either mef(A) or erm(B). Our results indicate that multidrug-resistant pneumococci are spreading rapidly in Japan. Efforts to prevent the spread of the pandemic multidrug-resistant serotypes should be intensified.     

粪肠球菌的耐药表型及大环内酯类耐药基因的检测

目的研究临床分离粪肠球菌的耐药情况及红霉素耐药基因erm(B)、erm(TR)、mef(A)和mef(E)的分布特点。方法采用K-B纸片法对2008-2009年临床分离的72株粪肠球菌进行7种抗菌药敏感性试验;PCR检测红霉素耐药基因erm(B)、erm(TR)、mef(A)和mef(E)。结果粪肠球菌对红霉素和四环素的耐药率分别为77.7%和80.5%,高浓度庆大霉素为50.0%;粪肠球菌对氨苄西林和左氧氟沙星保持较高的敏感率,耐药率分别为8.0%和13.9%;未发现对万古霉素和替考拉宁耐药的菌株;72株粪肠球菌均未检测出erm(TR)、mef(A)、mef(E)基因,有57株(79.1%)粪肠球菌检出erm(B)基因;54株红霉素耐药菌株的erm(B)基因携带率为96.4%,9株红霉素中介菌株的erm(B)基因携带率为33.3%,而7株红霉素敏感的粪肠球菌未检出erm(B)基因。结论粪肠球菌对红霉素和四环素的耐药率最高,对氨苄西林和左氧氟沙星保持较高的敏感性;分离株对大环内酯类药物耐药的主要机制是erm(B)编码的靶位改变。     

Antimicrobial-drug susceptibility of human and animal Salmonella typhimurium, Minnesota, 1997-2003

We compared antimicrobial resistance phenotypes and pulsed-field gel electrophoresis (PFGE) subtypes of 1,028 human and 716 animal Salmonella enterica serotype Typhimurium isolates from Minnesota from 1997 to 2003. Overall, 29% of human isolates were multidrug resistant. Predominant phenotypes included resistance to ampicillin, chloramphenicol or kanamycin, streptomycin, sulfisoxazole, and tetracycline (ACSSuT or AKSSuT). Most human multidrug-resistant isolates belonged to PFGE clonal group A, characterized by ACSSuT resistance (64%), or clonal group B, characterized by AKSSuT resistance (19%). Most animal isolates were from cattle (n = 358) or swine (n = 251). Eighty-one percent were multidrug resistant; of these, 54% were at least resistance phenotype ACSSuT, and 43% were at least AKSSuT. More than 80% of multidrug-resistant isolates had a clonal group A or B subtype. Resistance to ceftriaxone and nalidixic acid increased, primarily among clonal group A/ACSSuT isolates. Clonal group B/AKSSuT isolates decreased over time. These data support the hypothesis that food animals are the primary reservoir of multidrug-resistant S. Typhimurium.     

The epidemiology of multidrug-resistant Acinetobacter baumannii: does the community represent a reservoir?

OBJECTIVE: To explore the role of the community as a potential reservoir for Acinetobacter baumannii. DESIGN: Antimicrobial resistance patterns and genotypes of A. baumannii isolates from patients in two Manhattan hospitals were compared with those of A. baumannii isolates from the hands of community members. RESULTS: A total of 103 isolates from two hospitals (hospital A, 81; hospital B, 22) and 23 isolates from community residents were studied. Of the hospital isolates, 36.6% were multidrug resistant (hospital A, 68.2%; hospital B, 27.8%). In contrast, there were no multidrug-resistant isolates from the community (P < .005 between hospital and community). The prevalence of A. baumannii on the hands of community residents was 10.4% (23 of 222). By molecular typing, 42 strains of A. baumannii were identified. Of the isolates from hospital A and hospital B, 55.6% (45 of 81) and 68.2% (15 of 22), respectively, were indistinguishable or closely related. In contrast, most community (83.3%) isolates were unrelated (P = .001 between hospital and community). CONCLUSION: Acinetobacter isolates from the community, characterized by a large variety of unrelated strains (83.3%), were distinct from the hospital isolates, of which 58.3% were closely related. The absence of multidrug-resistant strains in the community compared with 36.8% prevalence among hospital isolates suggests that the reservoir for epidemic strains resides in the hospital environment itself. To our knowledge, this is the first study to examine the community as a potential reservoir for hospital strains of A. baumannii.     

Phenotypic and molecular characterization of Streptococcus pneumoniae in pre-conjugate vaccine era: A Chinese hospital-based retrospective study

BackgroundStreptococcus pneumoniae (S. pneumoniae) is an important pathogen in causing global morbidity and mortality among children. This study aimed to determine phenotypic and molecular characteristics of S. pneumoniae causing infections in children under five years in China.MethodsA hospital-based retrospective study was conducted. All 537 S. pneumoniae isolates were tested for antimicrobial susceptibility by E-test method, molecular characteristics including resistance genes, virulence genes and serotypes by multiplex polymerase chain reaction (PCR) method, and sequence types (STs) by sequencing seven housekeeping genes. Minimum spanning tree and correspondence analysis were used to reveal the potential relationship between serotypes and STs.ResultsMost of S. pneumoniae isolates were resistant to erythromycin (93.9%) and tetracycline (86.4%), with the predominant resistance genes being erm(B) (92.6%) and tet(M) (95.5%). The prevalent serotypes were 19F, 6B, 19A, 23F and 14, the coverage rate of PCV13 was high in 85.8%, and the predominant STs were ST271, ST320, ST3173, ST81 and ST876. A significant correlation existed between STs and serotypes, with ST271/19F and ST320/19A as the most prevalent clones. Notably, ST271/19F and ST320/19A isolates were associated with resistance to specific antibiotics and carrying of mef(A/E), rlrA and sipA genes.ConclusionsOur findings suggest the introduction of PCV13 vaccine to Chinese children, and underscore the value of monitoring multiple characteristics to detect new epidemiologic trends and provide implications for the formulation of multivalent pneumococcal vaccines.     

A novel multidrug-resistant PVL-negative CC1-MRSA-IV clone emerging in Ireland and Germany likely originated in South-Eastern Europe

This study investigated the recent emergence of multidrug-resistant Panton-Valentine leukocidin (PVL)-negative CC1-MRSA-IV in Ireland and Germany.Ten CC1-MSSA and 139 CC1-MRSA isolates recovered in Ireland between 2004 and 2017 were investigated. These were compared to 21 German CC1-MRSA, 10 Romanian CC1-MSSA, five Romanian CC1-MRSA and two UAE CC1-MRSA, which were selected from an extensive global database, based on similar DNA microarray profiles to the Irish isolates. All isolates subsequently underwent whole-genome sequencing, core-genome single nucleotide polymorphism (cgSNP) analysis and enhanced SCCmec subtyping.Two PVL-negative clades (A and B1) were identified among four main clades. Clade A included 20 German isolates, 119 Irish isolates, and all Romanian MRSA and MSSA isolates, the latter of which differed from clade A MRSA by 47–130 cgSNPs. Eighty-six Irish clade A isolates formed a tight subclade (A1) exhibiting 0–49 pairwise cgSNPs, 80 of which harboured a 46 kb conjugative plasmid carrying both ileS2, encoding high-level mupirocin resistance, and qacA, encoding chlorhexidine resistance. The resistance genes aadE, aphA3 and sat were detected in all clade A MRSA and the majority (8/10) of clade A MSSA isolates. None of the clade A isolates harboured any enterotoxin genes other than seh, which is universally present in CC1. Clade B1 included the remaining German isolate, 17 Irish isolates and the two UAE isolates, all of which corresponded to the Western Australia MRSA-1 (WA MRSA-1) clone based on genotypic characteristics. MRSA within clades A and B1 differed by 188 cgSNPs and clade-specific SCCmec characteristics were identified, indicating independent acquisition of the SCCmec element.This study demonstrated the existence of a European PVL-negative CC1-MRSA-IV clone that is distinctly different from the well-defined PVL-negative CC1-MRSA-IV clone, WA MRSA-1. Furthermore, cgSNP analysis revealed that this newly defined clone may have originated in South-Eastern Europe, before spreading to both Ireland and Germany.     

Emergence of high-risk multidrug-resistant Enterococcus faecalis CC2 (ST181) and CC87 (ST28) causing healthcare-associated infections in India

High-risk hospital-associated multidrug-resistant (MDR) Enterococcus faecalis clonal complexes (CCs) such as CC2 and CC87 are enriched with virulence determinants that help to accumulate, colonize, and cause serious nosocomial infections. The aim of this study was to establish the epidemiology and clonal composition of 134 clinical E. faecalis isolates and to link molecular typing data with antimicrobial resistance and virulence determinants. All isolates were identified by conventional methods and confirmed by polymerase chain reaction (PCR) (16srRNA gene and ddl genes of E. faecalis/ E. faecium) in 5-years. Disc diffusion test was performed on all strains. We screened all E. faecalis for aac(6′)-aph(2″), vanA, and vanB resistance genes, and aggregation substance-asa1, cytolysin-cylA, collagen-binding protein-ace, enterococcal surface protein-esp, gelatinase-gelE, and hyaluronidase-hyl virulence genes by PCR. Representative isolates of E. faecalis were characterized by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Out of 539 patients with enterococcal infections, 134 (24.9%) had E. faecalis infections, 366 (67.9%) had E. faecium infections, and 39 (7.2%) had infections due to other enterococcal species. Of the 134 isolates, 79.1% and 61.9% isolates were high-level gentamicin resistant (HLGR) and MDR. In multivariate analysis, independent predictor for infection due to MDR E. faecalis strains was a surgical intervention (OR 2.41, 95% CI 1.17–4.96, P = 0·017). Overall, the observed rate of in-hospital mortality was 11.9%. The gelE, asa1, ace, cylA, esp and hyl genes were detected in 87.3%, 78.4%, 54.5%, 53.7%, 36.6% and 3.0%, respectively in E. faecalis isolates. The asaI, cylA, and gelE genes were significantly correlated with MDR E. faecalis. The PFGE analysis showed 28 clones with four major clones. MLST analysis revealed two sequence types-ST28 (CC87) and ST181 (CC2). This is the first Indian report on the emergence of the high-risk hospital-associated worldwide-disseminated ST28 (CC87) and ST181 (CC2), which have enriched with multiple virulence determinants and resistance to antibiotics, paticularly ampicillin. This report indicates serious health concern and calls for on-going surveillance, close monitoring, and improved infection control procedures to stop further spread of these isolates.     

健康人携带金黄色葡萄球菌耐药表型及基因型研究

目的 调查我国健康人携带的金黄色葡萄球菌药物敏感性及大环内酯类耐药基因分布情况.方法 应用E-test方法,对2009－2011年收集的100株健康从业人员携带菌株进行16种抗生素的药物敏感性分析,以D 试验测定红霉素对克林霉素的诱导耐药表型.采用spa分型对上述菌株进行分型分析.利用PCR检测基因:甲基化酶[erm(A),erm(B),erm(C),erm(F),erm(T),erm(Y),erm(33)和erm(G)]、ATP结合转运蛋白[msr(A)和msr(D)]、主要易化子[mef(A)]、酯酶[ere(A)]及磷酸化酶[mph(C)],并与猪来源菌株38株(31株MRSA,7株MSSA)和患者来源MRSA菌株20株进行比较.结果 健康人群携带菌株对红霉素和克林霉素耐药率较高,分别为52%和27%.克林霉素诱导耐药率为29%.共鉴定35个spa型别,其中51.0%的spa型别为t189、t571、t002、t796、t437、t034和t701.52株健康人菌株主要携带erm(C)(57.7%)和erm(B)(34.6%), 95.0%的临床分离菌株携带erm(A), 100.0%猪鼻拭子分离菌株均携带erm(C)菌株.结论 携带erm(C)和erm(B)耐药基因的大环内酯类耐药菌株在健康人群中广泛存在,这些耐药基因在金黄色葡萄球菌中呈散在克隆传播.     

Serotypes,antimicrobial susceptibility,and molecular epidemiology of invasive and non-invasive Streptococcus pneumoniae isolates in paediatric patients after the introduction of 13-valent conjugate vaccine in a nationwide surveillance study conducted in Japan in 2012–2014

Pneumococcal infection in children is a major public health problem worldwide, including in Japan. The pneumococcal conjugate vaccine 7 (PCV7) was licensed for use in Japan in 2010 followed by PCV13 in 2013. This report includes the results of a nationwide surveillance of invasive pneumococcal disease (IPD) and non-IPD in paediatric patients from January 2012 to December 2014. We collected 343 isolates from 337 IPD patients and 286 isolates from 278 non-IPD patients. Of the IPD isolates, the most identified serotypes included 19A, 24F, and 15A. The prevalence of non-PCV13 serotype isolates increased significantly from 2012 to 2014 (51.6–71.4%, p = 0.004). Serotypes 19A, 15A and 35B were highly non-susceptible to penicillin, and the rates of non-susceptible isolates from IPD patients to penicillin and cefotaxime significantly declined during the study period (p = 0.029 and p = 0.013, respectively). The non-susceptible rate to meropenem increased, particularly for serotype 15A. The IPD isolates comprised clonal complex (CC) 3111 (93.8% was serotype 19A) followed by CC2572 (81.5% was serotype 24F) and CC63 (97.1% was serotype 15A). CC3111, CC63 and CC156 (33.3% was serotype 23A, 28.6% was serotype 6B, and 14.3% was serotype 19A) were highly non-susceptible to penicillin. Of the non-IPD isolates, the most identified serotypes included 19A, 15A, and 3. In conclusion, the introduction of PCV7 and PCV13 resulted in increasing non-PCV13 serotypes and clones, including antimicrobial resistant serotypes 15A and CC63 (Sweden^15A-25 clone).     

VIM-2-producing Multidrug-Resistant Pseudomonas aeruginosa ST175 Clone, Spain

A total of 183 patients were colonized or infected with multidrug-resistant Pseudomonas aeruginosa isolates at a hospital in Spain during 2007-2010; prevalence increased over this period from 2.8% to 15.3%. To characterize these isolates, we performed molecular epidemiologic and drug resistance analysis. Genotyping showed that 104 (56.8%) isolates belonged to a single major clone (clone B), which was identified by multilocus sequence typing as sequence type (ST) 175. This clone was initially isolated from 5 patients in 2008, and then isolated from 23 patients in 2009 and 76 patients in 2010. PCR analysis of clone B isolates identified the bla(VIM-2) gene in all but 1 isolate, which harbored bla(IMP-22). ST175 isolates were susceptible to only amikacin (75%) and colistin (100%). Emergence of the ST175 clone represents a major health problem because it compromises therapy for treatment of P. aeruginosa nosocomial infections.     

“一带一路”沿线国家耐多药结核病流行情况及变化趋势研究

目的分析"一带一路"沿线国家2019年耐多药结核病流行现状及2013-2019年该病的发病率变化趋势。方法选择与我国签署了共建"一带一路"合作文件的145个国家为研究对象, 其2013-2019年耐多药结核病的年龄标准化发病率和患病率资料来源于2019年全球疾病负担研究。采用145个国家2019年耐多药结核病的发病率及患病率描述流行现状;计算年估计百分比变化来分析耐多药结核病发病率在2013-2019年的变化趋势。结果 2019年, 145个国家中, 索马里的耐多药结核病的发病率(30.42/10万)和患病率(48.86/10万)最高, 斯洛文尼亚的发病率(0.01/10万)和患病率最低(0.01/10万)。2013-2019年, 在六大洲中, 非洲有14个(27.45%)国家耐多药结核病发病率呈上升趋势, 22个(43.14%)国家呈下降趋势;北美洲有2个(18.18%)国家发病率呈上升趋势, 有3个(27.27%)国家发病率呈下降趋势;亚洲有2个(5.41%)国家发病率呈上升趋势, 23个(62.16%)国家发病率呈下降趋势;欧洲、大洋洲、南美洲耐多药结核病发病率均无上升趋势, 欧...     

Prevalence of antimicrobial resistant Streptococcus pneumoniae serotype 11A isolates in Korea,during 2004–2013, due to the increase of multidrug-resistant clone,CC166

Since the introduction of the pneumococcal conjugate vaccine (PCV7) in Korea in 2003, the proportion of non-vaccine serotypes has increased. Among non-vaccine serotypes, serotype 11A is highly prevalent in Korea. We investigated the prevalence and characteristics of Streptococcus pneumoniae serotype 11A isolates in a Korean tertiary-care hospital, during 2004–2013. A total of 1579 non-duplicate clinical S. pneumoniae isolates, collected from 2004 to 2013, were included in this study. Serotype was determined by the capsular Quellung method, and in vitro susceptibility testing was performed by broth microdilution method. Multilocus sequence typing was performed to determine the genotypes of the S. pneumoniae isolates. We identified 90 serotype 11A isolates (5.7%). During this period, the proportion of serotype 11A has increased from 3.2% up to 13.2% (in 2012). Among the serotype 11A isolates, two main clonal complexes (CCs), CC166 and CC99, were identified. The increase of serotype 11A was mainly due to the increase of CC166 isolates, which have high antimicrobial resistance rates. In addition, we identified that 14 isolates, belonging to ST8279, ST9875, and ST3598 of CC166, were non-susceptible to all antimicrobial agents tested in this study. We identified the increase of S. pneumoniae serotype 11A in Korea, which mainly due to the expansion of a resistant clonal group, CC166.     

Drug resistance of Mycobacterium tuberculosis in Malawi: a cross-sectional survey

Objective

To document the prevalence of multidrug resistance among people newly diagnosed with – and those retreated for – tuberculosis in Malawi.

Methods

We conducted a nationally representative survey of people with sputum-smear-positive tuberculosis between 2010 and 2011. For all consenting participants, we collected demographic and clinical data, two sputum samples and tested for human immunodeficiency virus (HIV).The samples underwent resistance testing at the Central Reference Laboratory in Lilongwe, Malawi. All Mycobacterium tuberculosis isolates found to be multidrug-resistant were retested for resistance to first-line drugs – and tested for resistance to second-line drugs – at a Supranational Tuberculosis Reference Laboratory in South Africa.

Findings

Overall, M. tuberculosis was isolated from 1777 (83.8%) of the 2120 smear-positive tuberculosis patients. Multidrug resistance was identified in five (0.4%) of 1196 isolates from new cases and 28 (4.8%) of 581 isolates from people undergoing retreatment. Of the 31 isolates from retreatment cases who had previously failed treatment, nine (29.0%) showed multidrug resistance. Although resistance to second-line drugs was found, no cases of extensive drug-resistant tuberculosis were detected. HIV testing of people from whom M. tuberculosis isolates were obtained showed that 577 (48.2%) of people newly diagnosed and 386 (66.4%) of people undergoing retreatment were positive.

Conclusion

The prevalence of multidrug resistance among people with smear-positive tuberculosis was low for sub-Saharan Africa – probably reflecting the strength of Malawi’s tuberculosis control programme. The relatively high prevalence of such resistance observed among those with previous treatment failure may highlight a need for a change in the national policy for retreating this subgroup of people with tuberculosis.     

Distribution and susceptibility to amphotericin B and fluconazole of Candida spp. isolated from Taiwan

Susceptibilities to amphotericin B and fluconazole of 628 clinical yeast strains collected from 22 hospitals in Taiwan were determined. A total of 53 isolates (8.4%) were resistant to fluconazole. Each hospital had different resistance rate to fluconazole ranging from 0% to 24%. None of the 186 isolates from eight of the 22 hospitals was resistant to fluconazole. In contrast, isolates from nine of the remaining 14 hospitals had greater than 10% resistance rate to fluconazole. Consistently, 88.9% (8/9) fluconazole-resistant C. albicans isolates were from hospitals having a high resistance rate to fluconazole. The prevalence of various Candida spp. in each hospital was different. A positive association was found between the prevalence of C. tropicalis and the resistance rate to fluconazole for individual hospitals. Although only three isolates (0.5%) were resistant to amphotericin B, a co-resistance to both amphotericin B and fluconazole was observed, which highlights the emerging problem of drug resistance.     

肺炎链球菌对大环内酯类的耐药机制研究

目的 探讨台州医院肺炎链球菌临床分离株的耐药性及对红霉素的耐药机制,为临床用药提供依据.方法 收集临床分离的肺炎链球菌31株,运用K-B纸片法及VITEK细菌鉴定仪检测其对抗菌药物的药敏谱;通过纸片法筛选对大环内酯类抗菌药物(红霉素)的耐药表型,PCR扩增红霉素耐药基因:ermB、mefA,并送测序鉴定.结果 K-B法纸片药敏结果显示,肺炎链球菌临床分离株主要对红霉素、磺胺甲噁唑/甲氧苄啶和四环素耐药,耐药率分别为:100.0％、64.5％、32.2％;未发现有对青霉素、万古霉素及替考拉宁耐药的菌株;31株肺炎链球菌临床分离株耐药表型均为组成型耐药;31株红霉素耐药菌株的基因均为ermB(+)/mefA(+),测序结果正确.结论 台州医院肺炎链球菌临床分离株对红霉素耐药率高,erm基因介导的靶修饰作用和mef基因介导的外排泵机制的共同作用,是主要的耐药机制.     

91株肺炎链球菌的血清型分布及耐药性分析

目的 了解重庆地区肺炎链球菌临床分离株的血清型分布及药物敏感性.方法 采用荚膜肿胀试验进行肺炎链球菌血清学分型,并计算疫苗(PVC7、PVC11、PVC13)覆盖率;肉汤稀释法测定抗菌药物的最低抑菌浓度(MIC).结果 91株肺炎链球菌的临床分离患者年龄呈典型双峰分布,以＜5岁婴幼儿与＞50岁中老年人群为主,占51.7％、27.5％;90株肺炎链球菌共鉴定出20个血清型,1株未能血清分型,常见的肺炎链球菌血清型为19F、19A、6B,PVC13覆盖率为74.4％;91株肺炎链球菌均表现出较高的耐药率,在67株β-内酰胺类抗菌药物不敏感株(BLAs)中,青霉素不敏感菌株(PNSP)占53.8％.结论 重庆地区肺炎链球菌临床分离株以19F、19A、6B血清型为主,PVC13的预防作用更显著;肺炎链球菌耐药性高尤其是大多数菌株呈多药耐药趋势,临床应注意合理选择用药.     

Use of perioperative mupirocin to prevent methicillin-resistant Staphylococcus aureus (MRSA) orthopaedic surgical site infections

We have examined whether topical perioperative prophylaxis can reduce the incidence of methicillin-resistant Staphylococcus aureus (MRSA) surgical site infections (SSIs). Using a controlled before and after approach on patients from four orthopaedic wards, undergoing orthopaedic surgery involving insertion of metal prostheses and/or fixation, received perioperative prophylaxis with nasal mupirocin for five days, and a shower or bath with 2% (v/v) triclosan before surgery (PPNMT). After introduction of PPNMT there was a marked decrease in incidence of MRSA SSIs (per 1000 operations) from 23 in the six months beforehand (period A) to 3.3 (P<0.001) and 4 (P<0.001) in subsequent consecutive six-month periods (B and C, respectively). Of 11 MRSA SSI cases that occurred during periods B and C, only one had actually received PPNMT, and 10 occurred after acute, as opposed to elective, surgery (P<0.001). Point prevalence nasal MRSA carriage decreased from 38% before PPNMT to 23% immediately after, and 20%, 7%, 10% and 8% (P<0.001) at six-monthly intervals post-intervention. Conversely, the prevalence of nasal MRSA carriage in a control elderly medicine ward did not change significantly. Vancomycin usage, in terms of defined daily doses, declined by 23%. Low-level mupirocin resistance was found in 2.3% of S. aureus isolates from orthopaedic patients before PPNMT, and in 3.9%, 6.1%, 10% and 0% in subsequent six month periods. No S. aureus isolates with high-level mupirocin resistance were found. PPNMT can reduce the incidence of MRSA SSls after orthopaedic surgery, probably by reducing nasal MRSA carriage in the endemic setting, without selecting for mupirocin resistance.     

Molecular epidemiology of carbapenem-resistant Acinetobacter baumannii isolates reveals the emergence of blaOXA-23 and blaNDM-1 encoding international clones in India

Acinetobacter baumannii is a nosocomial pathogen increasingly affecting the critically ill patients and represents a major public health challenge. Carbapenem-resistant A. baumannii (CRAB) is found to be associated with International Clones (ICs) and different classes of carbapenemases. The objective of the present study was to investigate the prevalence of carbapenem resistance genes, clonal relationship and genetic structure of clinical isolates of A. baumannii. In the present study, multi-locus sequence typing (MLST^OX) and analysis were carried out using Oxford scheme for 86 clinical isolates of CRAB along with 11 carbapenem sensitive A. baumannii (CSAB) collected over a period of two years (2014–2016) from two tertiary care hospitals of North India. We observed a high prevalence of the bla_OXA-23-like (97.7%) among the CRAB followed by bla_NDM-1 (29.1%) and bla_OXA58-like (3.5%). Forty-seven Sequence Types (STs) were represented by all 97 isolates, out of which, 28 (59.6%) were novel STs that were assigned to 41 isolates. STs 451 (13%), 447 (7%), 195 (6%) and 848 (5%) were the most common STs. The majority of CRAB isolates (44.3%) belonged to the CC92, followed by the CC447 (15.1%), CC109 (9.3%) and CC110 (3.4%), which corresponds to the IC2, 8, 1 and 7 respectively. Phylogenetic and recombination analysis suggested two major and one minor lineage in the population. Further linkage disequilibrium analysis suggested clonal nature of the population as recombination was noticed at a low frequency, which was not enough to split the clonal relationship. The knowledge of genetic structure of CRAB from this study will be invaluable to illustrate epidemiology, surveillance and understanding its global diversity.     

Tuberculosis in Australia: bacteriologically confirmed cases and drug resistance, 2003. A report of the Australian Mycobacterium Reference Laboratory Network.

The Australian Mycobacterium Reference Laboratory Network collected and analysed laboratory data on new cases of disease caused by Mycobacterium tuberculosis complex in the year 2003. A total of 784 cases were identified by bacteriology, representing an annual reporting rate of 3.9 cases of laboratory confirmed tuberculosis per 100,000 population. The most commonly encountered culture-positive specimens were sputum (n = 351), lymph node (n = 176) and from bronchoscopy (n = 97). Smears containing acid fast bacilli were present in sputum (53.0%), bronchoscopy (32.0%) and lymph node (23.3%). Five children (female n = 3, male n = 2) under 10 years of age had bacteriologically confirmed tuberculosis. Eighty isolates of M. tuberculosis and one of Mycobacterium africanum (10.3%) were resistant to at least one of the standard anti-tuberculosis agents. Mono-resistance to isoniazid, ethambutol, rifampicin, and pyrazinamide was detected in 45, three, two, and one isolates respectively. Multidrug-resistance (MDRTB) defined as resistance to both isoniazid and rifampcin was observed in seven (0.9%) isolates. Of the seven MDRTB isolates, six were from the respiratory tract and four were from smear positive specimens. Of the 81 patients with drug resistant isolates, 78 (96.3%) were classified as having initial resistance; two had acquired resistance and no information was available for one isolate; five were Australian-born; and 76 (93.8%) had migrated from a total of 30 countries.     

Methicillin-resistant Staphylococcus aureus clones, Western Australia

Community-associated methicillin-resistant Staphylococcus aureus (MRSA) was first reported in Western Australia in the early 1990s from indigenous peoples living in remote areas. Although a statewide policy of screening all hospital patients and staff who have lived outside the state for MRSA has prevented the establishment of multidrug-resistant epidemic MRSA, the policy has not prevented SCCmec type IV and type V MRSA clones from becoming established. Of the 4,099 MRSA isolates analyzed (referred to the Gram-positive Bacteria Typing and Research Unit) from July 2003 to December 2004, 77.5% were community-associated MRSA (CA-MRSA). Using multilocus sequence/staphylococcal chromosome cassette mec typing, 22 CA-MRSA clones were characterized. Of these isolates, 55.5% were resistant to >1 non-beta-lactam antimicrobial drug. Five Panton-Valentine leukocidin (PVL)-positive CA-MRSA clones were identified. The emergence of multidrug-resistant CA-MRSA clones and the detection of PVL toxin genes in clones previously reported as PVL negative is a major public health concern.