British Society For Antimicrobial Chemotherapy Research Articles

Antimicrobial susceptibility of Helicobacter pylori strains isolated from children in Israel.

Helicobacter pylori is a bacterial pathogen causing inflammation of the gastric mucosa that may lead to peptic ulcer, perforation or malignancy. Children are at risk of contracting H. pylori and developing subsequent morbidity. Diagnosis and management in children are difficult and merit a different approach compared with adults. This study aimed to describe the antimicrobial resistance rates of H. pylori to amoxicillin, tetracycline, clarithromycin, metronidazole, levofloxacin and rifampicin. Biopsies (n=154) collected during endoscopic examinations were cultivated for 10days using a growth medium selective for H. pylori, of which 89 were H. pylori-positive. Antimicrobial resistance of the strains was assessed by Etest to establish minimum inhibitory concentrations (MICs) according to British Society for Antimicrobial Chemotherapy guidelines. Resistance rates were most notable for amoxicillin and clarithromycin at 12% and 35% with MICs of 0.74μg/mL and 2.51μg/mL, respectively. Resistance rates to tetracycline and levofloxacin were 8% and 2% with MICs of 2.57μg/mL and 2.0μg/mL, respectively. Resistance rates to rifampicin and metronidazole were 3% and 8% with MICs of 2.0μg/mL and 9.71μg/mL, respectively. Current rising antibiotic resistance rates for H. pylori are of concern. Performance of culture enables determination of the susceptibility profile, which may lead to a better choice of, and perhaps narrower spectrum, antibiotic agent. In light of these findings, we suggest that optimising the choice of antibiotic agent in children with H. pylori infection remains a challenge for clinicians and thus requires further investigation in randomised clinical trials.

Staphylococcus aureus urinary tract bacteriuria: single-institutional antibiotic susceptibility trends over a decade

Objectives: Methicillin resistant Staphylococcus aureus (MRSA) is a troublesome pathogen which is difficult for clinicians to treat. The purpose of this surveillance program is to assess the prevalence of MRSA urinary tract infections and determine risk factors for methicillin resistance in adults amongst urinary isolates of SA and to describe the antibiotic susceptibilities to guide empirical therapy.Methods: From 2005 through to 2014, we retrospectively reviewed urine cultures recorded in a laboratory database at a university hospital in Cambridge, UK. Susceptibility testing was performed by BSAC (British Society of Antimicrobial Chemotherapy) disc diffusion testing and reported for fluoroquinolones, gentamicin, nitrofurantoin, linezolid, trimethoprim and vancomycin. Samples were denoted “MRSA” if they were resistant to oxacillin or cefoxitin.Results: In total, 690 cultures were positive for SA, of which 293 (42.5%) were methicillin resistant. The number of SA bacteriuria decreased from around 100 per year to 40 per year. The proportion demonstrating methicillin resistance decreased from around 60% to around 20%. Both methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA isolates were susceptible to vancomycin and nitrofurantoin. MRSA isolates demonstrated some increased resistance to trimethoprim and gentamicin and greatly increased resistance to fluoroquinolones. Urinary catheterization and increasing age were risk factors for methicillin resistance.Conclusion: The incidence of SA and MRSA bacteriuria decreased during the study period. A high degree of resistance to fluoroquinolones was observed in MRSA compared to MSSA. Analysis of antibiotic susceptibility profiles suggests nitrofurantoin and trimethoprim may be useful in treating uncomplicated MSSA and MRSA urinary tract infections without concurrent bacteremia.

Corrigendum: Building a genomic framework for prospective MRSA surveillance in the United Kingdom and the Republic of Ireland.

The correct interpretation of microbial sequencing data applied to surveillance and outbreak investigation depends on accessible genomic databases to provide vital genetic context. Our aim was to construct and describe a United Kingdom MRSA database containing over 1000 methicillin-resistant Staphylococcus aureus (MRSA) genomes drawn from England, Northern Ireland, Wales, Scotland, and the Republic of Ireland over a decade. We sequenced 1013 MRSA submitted to the British Society for Antimicrobial Chemotherapy by 46 laboratories between 2001 and 2010. Each isolate was assigned to a regional healthcare referral network in England and was otherwise grouped based on country of origin. Phylogenetic reconstructions were used to contextualize MRSA outbreak investigations and to detect the spread of resistance. The majority of isolates (n = 783, 77%) belonged to CC22, which contains the dominant United Kingdom epidemic clone (EMRSA-15). There was marked geographic structuring of EMRSA-15, consistent with widespread dissemination prior to the sampling decade followed by local diversification. The addition of MRSA genomes from two outbreaks and one pseudo-outbreak demonstrated the certainty with which outbreaks could be confirmed or refuted. We identified local and regional differences in antibiotic resistance profiles, with examples of local expansion, as well as widespread circulation of mobile genetic elements across the bacterial population. We have generated a resource for the future surveillance and outbreak investigation of MRSA in the United Kingdom and Ireland and have shown the value of this during outbreak investigation and tracking of antimicrobial resistance.

Activity of temocillin and 15 other agents, including fosfomycin and colistin, against Enterobacteriaceae in Hong Kong

Limited data are available on temocillin susceptibilities in Enterobacteriaceae from Asian countries where antimicrobial resistance is prevalent. The in vitro activities of temocillin and 15 commonly used antimicrobials against 613 non-duplicate blood (n = 310) and urine (with clinically significant bacteriuria; n = 303) isolates of Enterobacteriaceae from patients who attended 3 out of 7 clusters of public hospitals of the Hospital Authority, Hong Kong, during 2015/2016 were tested. Minimum inhibitory concentrations (MICs) were determined by Clinical and Laboratory Standards Institute (CLSI) microbroth dilution (agar dilution with fosfomycin). For temocillin, MICs were also obtained using the British Society of Antimicrobial Chemotherapy (BSAC) microbroth dilution method and interpreted using the BSAC breakpoints. Overall, 93.0% (570) isolates were susceptible to temocillin using BSAC systemic breakpoint (≤8 mg/L) and all except 2 isolates were susceptible using the urinary breakpoint (≤32 mg/L). The extended spectrum beta-lactamase (ESBL) positivity rate was 23.2% (118 out of 508 E. coli, Klebsiella spp., Proteus spp.). Temocillin resistance rate to ESBL-positive isolates was 16.1% using the systemic breakpoint of ≤8 mg/L (MIC50 and MIC90 were 8 mg/L and 16 mg/L respectively). Two isolates (1 E. coli, temocillin MIC 64 mg/L, 1 Klebsiella sp., MIC 32 mg/mL) were resistant to meropenem and possessed the NDM-5 and KPC-2 genes respectively. Other susceptibility rates were: amoxicillin/clavulanate (59.1%), trimethoprim/sulfamethoxazole (62.5%), ciprofloxacin (71.5%), ceftriaxone (75.4%), nitrofurantoin (76.4%), gentamicin (78.3%), cefepime (81.1%), ceftazidime (83.5%), piperacillin/tazobactam (86%), colistin (88.8%), tigecycline (89.4%), fosfomycin (92.8%), ertapenem (99.0%), amikacin (99.2%) and meropenem (99.7%). Temocillin may be a useful alternative for the treatment of infections caused by ESBL and multi-drug-resistant Enterobacteriaceae in Hong Kong, particularly as resistance rates to ciprofloxacin, nitrofurantoin and piperacillin/tazobactam are high.

Prevalence and trends in the antimicrobial susceptibility pattern of Salmonella enterica serovars Typhi and Paratyphi A among children in a pediatric tertiary care hospital in South India over a period of ten years: a retrospective study.

The aim of this study was to determine the prevalence and trends in the antimicrobial resistance of typhoidal salmonellae in children and adolescents at a pediatric tertiary care hospital in South India. Typhoidal salmonellae were isolated from 483 of the 77,713 blood cultures received during the ten-year study period (2007-2016). Isolates were speciated by conventional biochemical reactions and serotyping. Antimicrobial susceptibility testing was performed and interpreted according to the British Society for Antimicrobial Chemotherapy (BSAC)/European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. The overall blood culture isolation rates of Salmonella enterica serovars Typhi and Paratyphi A in children were 0.5% (408 cases) and 0.1% (73 cases), respectively, with the highest isolation rates in school [299 (61.9%)] and preschool children [113 (23.4%)]. A decreasing prevalence of enteric fever was seen from 2012 to 2015, with a sudden surge in 2016. From 2011 onwards, a high fluoroquinolone resistance (90-100%) was observed. Multidrug resistance was observed in only four (0.9%) S. Typhi isolates. 100% susceptibility to third-generation cephalosporins and azithromycin was noted. Enteric fever as seen in a pediatric tertiary care hospital in India affects children and adolescents of all age groups, with greater isolation rates in school children, followed by those in preschool years, calling for targeted interventions against these age groups. The study findings support the use of third-generation cephalosporins and azithromycin as first-line therapy and ampicillin and co-trimoxazole as step-down therapy in pediatric enteric fever. However, continued local surveillance should be done to detect antimicrobial resistance trends to optimize treatment.

Systematic longitudinal survey of invasive Escherichia coli in England demonstrates a stable population structure only transiently disturbed by the emergence of ST131.

Escherichia coli associated with urinary tract infections and bacteremia has been intensively investigated, including recent work focusing on the virulent, globally disseminated, multidrug-resistant lineage ST131. To contextualize ST131 within the broader E. coli population associated with disease, we used genomics to analyze a systematic 11-yr hospital-based survey of E. coli associated with bacteremia using isolates collected from across England by the British Society for Antimicrobial Chemotherapy and from the Cambridge University Hospitals NHS Foundation Trust. Population dynamics analysis of the most successful lineages identified the emergence of ST131 and ST69 and their establishment as two of the five most common lineages along with ST73, ST95, and ST12. The most frequently identified lineage was ST73. Compared to ST131, ST73 was susceptible to most antibiotics, indicating that multidrug resistance was not the dominant reason for prevalence of E. coli lineages in this population. Temporal phylogenetic analysis of the emergence of ST69 and ST131 identified differences in the dynamics of emergence and showed that expansion of ST131 in this population was not driven by sequential emergence of increasingly resistant subclades. We showed that over time, the E. coli population was only transiently disturbed by the introduction of new lineages before a new equilibrium was rapidly achieved. Together, these findings suggest that the frequency of E. coli lineages in invasive disease is driven by negative frequency-dependent selection occurring outside of the hospital, most probably in the commensal niche, and that drug resistance is not a primary determinant of success in this niche.

British Society of Antimicrobial Chemotherapy appoints first pharmacist president

British Society of Antimicrobial Chemotherapy appoints first pharmacist president

Rise of multidrug-resistant non-vaccine serotype 15A Streptococcus pneumoniae in the United Kingdom, 2001 to 2014.

Conjugate vaccines have reduced pneumococcal disease in vaccinated children and unvaccinated adults, but non-vaccine serotypes are of concern, particularly if antibiotic resistant. We reviewed Streptococcus pneumoniae collected via: (i) the British Society for Antimicrobial Chemotherapy (BSAC) surveillances from 2001–2014; (ii) Public Health England’s (PHE) invasive isolate surveillance from 2005–2014 and (iii) referral to PHE for resistance investigation from 2005–2014. Serotype 15A increased in all series, with many representatives showing triple resistance to macrolides, tetracyclines and penicillin. 15A was consistently among the 10 most prevalent serotypes from 2011 in PHE and BSAC invasive isolate/bacteraemia surveillance but never previously; 26–33% of these invasive 15A isolates had triple resistance. BSAC respiratory isolates were only serotyped in 2013/14 and 2014/15 (October to September); 15A was most prevalent serotype in both periods, comprising 9–11% of isolates, 38–48% of them with triple resistance. Serotype 15A represented 0–4% of S. pneumoniae referred to PHE for reference investigation annually until 2008 but rose to 29% (2013) and 32% (2014). Almost all multidrug-resistant 15A isolates were sequence type (ST) 63 variants, whereas susceptible 15A isolates were clonally diverse. The rise of serotype 15A suggests that pneumococcal conjugate vaccines will need ongoing adaptation.

Adult bacterial conjunctivitis: resistance patterns over 12 years in patients attending a large primary eye care centre in the UK

PurposeTo determine whether there was a change in the resistance pattern of bacteria isolated from cases of conjunctivitis following the introduction of over-the-counter availability of chloramphenicol in 2005.Design and settingRetrospective...

Analysis of nasopharyngeal carriage rate and antibiotic resistance of Moraxella catarrhalis isolates collected from children with respiratory tract infections

Objective To investigate the nasopharyngeal carriage rate and antibiotic resistance profiles of Moraxella catarrhalis among children with respiratory tract infections in Chongqing Youyang County in order to provide data for clinical drug selection. Methods Nasopharyngeal swab specimens were collected from children with respiratory tract infection admitted at the Department of Pediatrics, Youyang Hospital, the First Affiliated Hospital of Chongqing Medical University from January to December in 2015, and Moraxella catarrhalis isolates were tested and collected.The antibiotic susceptibility was tested by E-test method and disc diffusion tests, and susceptibility was judged according to breakpoints in European Committee on Antimicrobial Susceptibility Testing(EUCAST), Clinical and Laboratory Stan-dards Institute(CLSI 2014)and British Society for Antimicrobial Chemotherapy(BSAC). β-lactamase activity was determined by the chromogenic cephalosporin nitrocefin. Results The nasopharyngeal carriage rate of Moraxella catarrhalis was 9.6%(101/1 054 cases) in children aged 1 month to 12 years old, major in winter (13.8%, 52/378 cases) among children younger than 3 years old(10.5%, 90/860 cases). The carriage rate was low in summer(4.0%, 8/200 cases). The positive rate of β-lactamase was 99.0%(100/101 cases). All of the isolates were sensitive to Amoxycillin-Clavulanate.Most of the isolates were sensitive to Cephalosporin antibiotics according to EUCAST and CLSI 2014 criteria.According to CLSI 2014, the resistance rate to Erythromycin was 15.8%(16/101 cases). The resistance rate to Ampicillin was 68.3%(69/101 cases)on the basis of the BSAC breakpoints, and the intermediate rate and resistant rate to Cefuroxime were 45.5%(46/101 cases)and 49.5%(50/101 cases), respectively. Conclusions Moraxella catarrhalis was mostly seen among children younger than 3 years old with respiratory tract infections, especially in winter.The results indicated that 99.0% of the isolates were positive in β-lactamase, but all of the isolates were sensitive to Amoxycillin-Clavulanate. Key words: Moraxella catarrhalis; Carriage rate; Antibiotic resistance; Child

Investigation of the frequency and distribution of beta-lactamase genes in the clinical isolates of Acinetobacter baumannii collected from different regions of Turkey: a multicenter study

The diversity and distribution of TEM, SHV and CTX-M type of extended-spectrum beta-lactamases (ESBLs) are important for the treatment and control of infections. Determination of ESBL genes in clinical isolates by polymerase chain reaction (PCR) and DNA sequencing can obtain useful data for their molecular epidemiology and risk. The aim of this study was to investigate the frequency of beta-lactamase genes in Acinetobacter baumannii strains isolated from different regions of Turkey. A total of 519 A.baumannii strains collected from hospitals located at 12 different provinces of Turkey (Bolu (n= 67), Tokat (n= 47), Trabzon (n= 25), Ordu (n= 27), Diyarbakır (n= 47), Niğde (n=31), Kayseri (n= 36), Ankara (n= 41), Kirikkale (n= 26), Kahramanmaraş (n= 25), Mersin (n= 40), Istanbul (n= 107)] between 2011-2012 period were included in the study. Identification of the isolates were performed by both conventional methods and automated systems, VITEK2 Compact (BioMerieux, France) and API 32GN (BioMerieux, France). Disc diffusion method was used for the detection of antibiotic susceptibilities of the isolates and the results were evaluated according to CLSI (Clinical and Laboratory Standards Institute) criteria. Tigecycline and colistin sensitivities of the isolates were evaluated according to BSAC (British Society for Antimicrobial Chemotherapy) criteria. The presence of beta-lactamase genes, namely blaoxa-51, blaTEM, blaSHV, blaCTX-M1, blaCTX-M2, blaGES and blaVIM were detected by PCR. In our study, the resistance rates against colistin, tigecycline, ampicillin-sulbactam, amoxicillin-clavulanic acid, cefoperazone/sulbactam, tobramycin, ceftriaxone, piperacillin-tazobactam, gentamicin, ampicillin, tetracycline, cefepime, piperacillin, amikacin, trimethoprim-sulfamethoxazole, meropenem, levofloxacin, ciprofloxacin, imipenem and ceftazidime were detected as; 0.6%, 2.7%, 11.9%, 15.2%, 21%, 22.9%, 23.9%, 48.6%, 59.5%, 61.8%, 66.3%, 67.8%, 69.2%, 71.1%, 77.5%, 78.6%, 81.1%, 82.9%, 87.5% and 89.4%, respectively. All of the isolates (100%) were OXA-51 positive, while 443 (85.4%) out of 519 strains harbored other beta-lactamase genes searched in the study. When the distribution of the genes were evaluated, blaTEM-1 was found as the predominant one with a frequency rate of 55.7% (n=289/519), followed by blaCTX-M2 (63/519, 12.1%), blaCTX-M1 (42/519, 8.1%), blaSHV (40/519, 7.7%), blaGES (8/519, 1.5%) and blaVIM (1/519, 0.2%). Cooccurence of ESBL genes was detected in 16.3% (72/443) of the strains, being mostly TEM+CTX-M2 (20/72, 27.8%), TEM+SHV (11/72, 15.3%) and TEM+CTX-M1 (10/72, 13.9%). In addition, it was noted that the distribution of ESBL genes between isolates showed differences according to the provinces. Accordingly, none of the strains isolated from four provinces (Bolu, Niğde, Mersin, Kahramanmaraş) and from three provinces (Bolu, Kahramanmaraş, Diyarbakir) harbored blaCTX-M1/M2 and blaSHV genes, respectively. The blaTEM gene was detected in isolates collected from all of the provinces, with a highest frequency in Niğde (28/31, 90.3%) and lowest in Trabzon (1/25, 4%). The presence of GES-11 type ESBLs was found only in the isolates sent from Niğde province (8/31; 25.8%). Screening of metallo-beta-lactamase VIM gene also yielded a single positive result amongst only Niğde isolates (1/31; 3.2%), and this gene was identified as VIM-5 type by DNA sequencing. This study which is the first comprehensive national research to characterize ESBLs in A.baumannii isolates by molecular methods, showed that the most prevalent ESBL type is TEM (289/519, 55.7%) amongst A.baumannii strains isolated from different regions of our country. The data of our study is parallel to the results of previous studies carried out from Turkey.

Antibiotics for ventilator-associated pneumonia.

Ventilator-associated pneumonia (VAP) is a significant cause of morbidity and mortality, complicating the medical course of approximately 10% of mechanically-ventilated patients, with an estimated attributable mortality of 13%. To treat VAP empirically, the American Thoracic Society currently recommends antibiotic therapy based on the patients' risk of colonisation by an organism with multidrug resistance. The selection of initial antibiotic therapy in VAP is important, as inappropriate initial antimicrobial treatment is associated with higher mortality and longer hospital stay in intensive care unit (ICU) patients.While guidelines exist for the antibiotic treatment of hospital-acquired pneumonia (HAP) from the American Thoracic Society and the British Society for Antimicrobial Chemotherapy, there are many limitations in the quality of available evidence. This systematic review aimed to summarise the results of all randomised controlled trials (RCTs) that compare empirical antibiotic regimens for VAP. The primary objective of this review was to assess the effect of different empirical antimicrobial therapies on the survival and clinical cure of adult patients with ventilator-associated pneumonia (VAP). Secondary objectives included reporting the incidence of adverse events, new superinfections, length of hospital stay, and length of intensive care unit (ICU) stay associated with these therapies. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS, CINAHL and Web of Science to December 2015; we searched ClinicalTrials.gov to September 2016. Two review authors independently assessed RCTs comparing empirical antibiotic treatments of VAP in adult patients, where VAP was defined as new-onset pneumonia that developed more than 48 hours after endotracheal intubation. Physicians and researchers were not required to be blinded for inclusion in this review. Two review authors independently extracted study data. We pooled studies and analysed them in two ways. We examined monotherapy, or a single experimental antimicrobial drug, versus combination therapy, or multiple experimental antimicrobial drugs. We also examined carbapenem therapy versus non-carbapenem therapy. We included 12 studies with 3571 participants. All included studies examined the empiric use of one antimicrobial regimen versus another for the treatment of adults with VAP, but the particular drug regimens examined by each study varied. There was potential for bias because some studies did not report outcomes for all participants. All but one study reported sources of funding or author affiliations with pharmaceutical companies.We found no statistical difference in all-cause mortality between monotherapy and combination therapy (N = 4; odds ratio (OR) monotherapy versus combination 0.97, 95% confidence interval (CI) 0.73 to 1.30), clinical cure (N = 2; OR monotherapy versus combination 0.88, 95% CI 0.56 to 1.36), length of stay in ICU (mean difference (MD) 0.65, 95% CI 0.07 to 1.23) or adverse events (N = 2; OR monotherapy versus combination 0.93, 95% CI 0.68 to 1.26). We downgraded the quality of evidence for all-cause mortality, adverse events, and length of ICU stay to moderate for this comparison. We determined clinical cure for this comparison to be of very low-quality evidence.For our second comparison of combination therapy with optional adjunctives only one meta-analysis could be performed due to a lack of trials comparing the same antibiotic regimens. Two studies compared tigecycline versus imipenem-cilastatin for clinical cure in the clinically evaluable population and there was a statistically significant increase in clinical cure for imipenem-cilastatin (N = 2; OR tigecycline versus imipenem-cilastatin 0.44, 95% CI 0.23 to 0.84). Of importance, this effect was due to a single study.We found no statistical difference in all-cause mortality between carbapenem and non-carbapenem therapies (N = 1; OR carbapenem versus non-carbapenem 0.59, 95% CI 0.30 to 1.19) or adverse events (N = 3; OR carbapenem versus non-carbapenem 0.78, 95% CI 0.56 to 1.09), but we found that carbapenems are associated with a statistically significant increase in the clinical cure (N = 3; OR carbapenem versus non-carbapenem 1.53, 95% CI 1.11 to 2.12 for intention-to-treat (ITT) analysis and N = 2; OR carbapenem versus non-carbapenem 2.29, 95% CI 1.19 to 4.43 for clinically evaluable patients analysis). For this comparison we downgraded the quality of evidence for mortality, and clinical cure (ITT and clinically evaluable populations) to moderate. We determined the quality of evidence for adverse events to be low. We did not find a difference between monotherapy and combination therapy for the treatment of people with VAP. Since studies did not identify patients with increased risk for multidrug-resistant bacteria, these data may not be generalisable to all patient groups. However, this is the largest meta-analysis comparing monotherapy to multiple antibiotic therapies for VAP and contributes further evidence to the safety of using effective monotherapy for the empiric treatment of VAP.Due to lack of studies, we could not evaluate the best antibiotic choice for VAP, but carbapenems as a class may result in better clinical cure than other tested antibiotics.

Antimicrobial stewardship in wound care: a Position Paper from the British Society for Antimicrobial Chemotherapy and European Wound Management Association.

With the growing global problem of antibiotic resistance it is crucial that clinicians use antibiotics wisely, which largely means following the principles of antimicrobial stewardship (AMS). Treatment of various types of wounds is one of the more common reasons for prescribing antibiotics. This guidance document is aimed at providing clinicians an understanding of: the basic principles of why AMS is important in caring for patients with infected wounds; who should be involved in AMS; and how to conduct AMS for patients with infected wounds. We assembled a group of experts in infectious diseases/clinical microbiology (from the British Society for Antimicrobial Chemotherapy) and wound management (from the European Wound Management Association) who, after thoroughly reviewing the available literature and holding teleconferences, jointly produced this guidance document. All open wounds will be colonized with bacteria, but antibiotic therapy is only required for those that are clinically infected. Therapy is usually empirical to start, but definitive therapy should be based on results of appropriately collected specimens for culture. When prescribed, it should be as narrowly focused, and administered for the shortest duration, as possible. AMS teams should be interdisciplinary, especially including specialists in infection and pharmacy, with input from administrative personnel, the treating clinicians and their patients. Available evidence is limited, but suggests that applying principles of AMS to the care of patients with wounds should help to reduce the unnecessary use of systemic or topical antibiotic therapy and ensure the safest and most clinically effective therapy for infected wounds.

Critical review on retrospective and prospective changes in antifungal susceptibility testing for dermatophytes.

Antifungal susceptibility testing is a progressive field of mycology with respect to dermatophytes as well as non-dermatophytes. Documentation and approval regarding standardisation of in vitro susceptibility testing have been done by different governing bodies such as Clinical and Laboratory Standards Institute, European Committee on Antimicrobial Susceptibility Testing and British Society of Antimicrobial Chemotherapy. The process of standardisation and approval started in 1985 with certain amendments in 2002 and 2004. In case of dermatophytes, antifungal susceptibility testing protocol has been approved recently in 2008; however, the approved standardisation also needs certain amendments/modifications due to the limitations of an existing method. In the present review, we have compiled these standardisation techniques along with the limitations and advantages and the amendments that have been proposed at different time periods by different researchers and regulatory agencies.

Behind the scenes of JAC: the British Society for Antimicrobial Chemotherapy.

This brief article describes the relationship between the British Society for Antimicrobial Chemotherapy (BSAC) and JAC, and how JAC has directly and indirectly facilitated delivery of the BSAC's charitable objectives over the past 40 years.

Infective endocarditis prophylaxis in patients undergoing oral surgery

Infective endocarditis (IE), an infection of the endocardium that usually involves the valves and adjacent structures, may be caused by a wide variety of bacteria and fungi that entered the bloodstream and settled in the heart lining, a heart valve or a blood vessel. The IE is uncommon, but people with some heart conditions have a greater risk of developing it. Despite advances in medical, surgical, and critical care interventions, the IE remains a disease that is associated with considerable morbidity and mortality. Hence, in order to minimize the risk of adverse outcome and achieve a yet better management of complications, it is crucial to increase the awareness of all the prophylactic measures of the IE. For the past 50 years, the guidelines for the IE prophylaxis have been under constant changes. The purpose of this paper is to review current dental and medical literature considering the IE prophylaxis, including the new and updated guidelines from the American Heart Association (AHA, 2007 and 2015), the National Institute for Health and Clinical Excellence (NICE, 2015), the European Society of Cardiology (ESC, 2009 and 2015) and the British Society for Antimicrobial Chemotherapy (BSAC, 2006).

Building a genomic framework for prospective MRSA surveillance in the United Kingdom and the Republic of Ireland.

The correct interpretation of microbial sequencing data applied to surveillance and outbreak investigation depends on accessible genomic databases to provide vital genetic context. Our aim was to construct and describe a United Kingdom MRSA database containing over 1000 methicillin-resistant Staphylococcus aureus (MRSA) genomes drawn from England, Northern Ireland, Wales, Scotland, and the Republic of Ireland over a decade. We sequenced 1013 MRSA submitted to the British Society for Antimicrobial Chemotherapy by 46 laboratories between 2001 and 2010. Each isolate was assigned to a regional healthcare referral network in England and was otherwise grouped based on country of origin. Phylogenetic reconstructions were used to contextualize MRSA outbreak investigations and to detect the spread of resistance. The majority of isolates (n = 783, 77%) belonged to CC22, which contains the dominant United Kingdom epidemic clone (EMRSA-15). There was marked geographic structuring of EMRSA-15, consistent with widespread dissemination prior to the sampling decade followed by local diversification. The addition of MRSA genomes from two outbreaks and one pseudo-outbreak demonstrated the certainty with which outbreaks could be confirmed or refuted. We identified local and regional differences in antibiotic resistance profiles, with examples of local expansion, as well as widespread circulation of mobile genetic elements across the bacterial population. We have generated a resource for the future surveillance and outbreak investigation of MRSA in the United Kingdom and Ireland and have shown the value of this during outbreak investigation and tracking of antimicrobial resistance.

Identification of genetic variation exclusive to specific lineages associated with Staphylococcus aureus bacteraemia

Meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia cases have declined since 2003, and have mostly been due to two epidemic (E) strains, E15 (multi-locus sequence type clonal complex CC22) and E16 (CC30). By contrast, the incidence of meticillin-susceptible S. aureus (MSSA) bacteraemia has remained largely unchanged and our understanding of these isolates has remained poor. To investigate the distribution and nucleotide sequence of heterogeneous regions between successful lineages using the 2009 British Society for Antimicrobial Chemotherapy (BSAC) Bacteraemia Resistance Surveillance Programme collection of S. aureus. S. aureus isolates (N = 202) comprised of 103 MRSA and 99 MSSA isolates were analysed using fluorescent amplified fragment length polymorphism (FAFLP) to detect nucleotide variations due to lineage-specific sequence motifs as well as differences in the distribution of mobile genetic elements between lineages. E15 and E16 MRSA strains comprised 79% and 6% of the collection in 2009 respectively. Six lineages, including CC22 and CC30, were associated with MRSA bacteraemia in the UK and Ireland. MSSA isolates were more diverse with 19 different lineages detected. FAFLP revealed lineage-specific sequence variations in loci encoding factors such as proteases or factors involved in haem biosynthesis, both of which may affect the success of major S. aureus lineages. Proteins encoded on certain mobile genetic elements or involved in cobalamin biosynthesis were found to be exclusive to CC8, CC22, or CC30. Overall, the genetic diversity among regions of the core genome and mobile genetic elements may alter antimicrobial resistance and the production of virulence or fitness factors that may be linked to strain success.

A method for early detection of antibiotic resistance in positive blood cultures: Experience from an oncology centre in eastern India

Purpose: For antibiotic susceptibility results, conventional culture and sensitivity methods takes 48 hours after a blood culture is flagged positive by automated systems. Early initiation of targeted antibiotic therapy is essential for effective management of sepsis to reduce morbidity, mortality, cost of treatment and prevent antibiotic resistance. Objective of this study was to evaluate Direct Sensitivity Test (DST) as a potential tool to get reliable antibiotic susceptibility results 24 hours earlier. Materials and Methods: Blood cultures flagged positive between May 2011 to December 2012 by BacT/ALERT were Gram stained. All uni-microbial gram-negative blood cultures were simultaneously cultured and processed for DST from broth using disk diffusion method using British Society of Antimicrobial Chemotherapy (BSAC) guidelines. DST results available next day were compared with conventional antibiotic susceptibility test (AST) performed by Vitek-2 on isolated colonies. Results of DST (test method) and AST (reference method) were compared for agreements or errors. Results: Of the 840 antibiotic gram-negative organism combinations tested, Categorical and essential agreements were 83.7% and 96.2% respectively. Minor, major and very major errors were 12.5%, 3.33% and 0.47%, respectively. Conclusions: DST using disk diffusion from positive blood culture broths helps to initiate early targeted antibiotic therapy. There is high concordance between DST and AST.

Incidence, management and outcomes of the first cfr-mediated linezolid-resistant Staphylococcus epidermidis outbreak in a tertiary referral centre in the Republic of Ireland

To report the first Irish outbreak of cfr-mediated linezolid-resistant Staphylococcus epidermidis. Linezolid-resistant S. epidermidis isolated at University Hospital Limerick from four blood cultures, one wound and four screening swabs (from nine patients) between April and June 2013 were characterized by pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST) and staphylococcal cassette chromosome (SCCmec) typing. Antibiotic susceptibilities were determined according to the guidelines of the British Society for Antimicrobial Chemotherapy. The outbreak was controlled through prohibiting prescription and use of linezolid, adherence to infection prevention and control practices, enhanced environmental cleaning, isolation of affected patients, and hospital-wide education programmes. PFGE showed that all nine isolates represented a single clonal strain. MLST showed that they belonged to ST2, and SCCmec typing showed that they encoded a variant of SCCmecIII. All nine isolates were cfr positive, and eight isolates were positive for the G2576T 23S rRNA mutation commonly associated with linezolid resistance. Isolates exhibited multiple antibiotic resistances (i.e. linezolid, gentamicin, methicillin, clindamycin, ciprofloxacin, fusidic acid and rifampicin). The adopted infection prevention intervention was effective, and the outbreak was limited to the affected intensive care unit. This is the first documented outbreak of cfr-mediated linezolid-resistant S. epidermidis in the Republic of Ireland. Despite this, and due to existing outbreak management protocols, the responsible micro-organism and source were identified efficiently. However, it became apparent that staff knowledge of antimicrobial susceptibilities and appropriate hygiene practices were suboptimal at the time of the outbreak, and that educational interventions (and re-inforcement) are necessary to avoid occurrence of antimicrobial resistance and outbreaks such as reported here.