William Ba-Thein

Identification of first exfoliative toxin in Staphylococcus pseudintermedius

Staphylococcus aureus, Staphylococcus hyicus, and Staphylococcus chromogenes are known to cause skin infections in human or animals by producing exfoliative toxins (ETs). Staphylococcus pseudintermedius can also cause canine pyoderma, but no exfoliative toxins or similar toxins have been reported. PCR with degenerate primers targeted to the conserved regions in ETA, ETB, and ETD from S. aureus and SHETB from S. hyicus, and subsequent chromosome walking identified a novel gene, designated as exi (exfoliative toxin of pseudintermedius) in S. pseudintermedius. EXI had significant homologies with the exfoliative toxins (43-68% identity), particularly with ETB (67.1%), ETD (67.9%), and SHETB (65.1%). Phylogenetic analysis showed close relation between EXI and ETB with a bootstrap value of 80%. Neonatal mice injected with the crude proteins from the culture supernatant or recombinant EXI showed gross blisters and/or characteristic skin exfoliation. The prevalence of exi assessed by dot-blot hybridization was 23.3% (10/43) in S. pseudintermedius isolates from canine pyoderma. The EXI reported herein is the first exfoliative toxin identified in S. pseudintermedius.

Viral aetiology of acute respiratory infections among children and associated meteorological factors in southern China

BackgroundAcute respiratory infections (ARIs) are common in children and mostly caused by viruses, but the significance of the detection of multiple viruses in ARIs is unclear. This study investigated 14 respiratory viruses in ARIs among children and associated meteorological factors in Shantou, southern China.MethodsPaired nasal/throat-flocked swabs collected from 1,074 children with ARIs, who visited outpatient walk-in clinics in a tertiary hospital between December 2010 and November 2011, were examined for fourteen respiratory viruses - influenza viruses (FluA, FluB), respiratory syncytial viruses (RSV A and B), human coronaviruses (hCoV: 229E, OC43, HKU1, NL63), human metapneumoviruses (hMPV A and B), parainfluenza viruses (PIV1-4), human rhinoviruses (HRV A, B, C), enteroviruses (EV), adenoviruses (ADV), human bocavirus (hBoV), and human parechoviruses (hPeV) - by multiplex real-time PCR.ResultsWe identified at least one virus in 82.3% (884/1,074) and multiple viruses in 38.6% (415/1,074) of patients. EV and HRV were the most frequently detected single viruses (42.3%, 374/884 and 39.9%, 353/884 respectively) and co-detected pair (23.1%, 96/415). Overlapping seasonal trends of viruses were recorded over the year, with dual peaks for EV and single peaks for the others. By logistic regression analysis, EV was positively associated with the average temperature and humidity, hCoV, and PIV4, but negatively with HRV, PIV3, and hBoV. HRV was inversely associated with EV and PIV3.ConclusionsThis study reports high viral detection and co-detection rates in pediatric ARI cases mainly due to EV and HRV. Many viruses circulated throughout the year with similar seasonal trends in association with temperature, humidity, and wind velocity. Statistically significant associations were present among the viruses. Understanding the polyviral etiology and viral interactions in the cases with multiple viruses warrants further studies.

Self-medication practices with antibiotics among Chinese university students.

OBJECTIVES Self-medication with antibiotics (SMA) is a serious global health problem. We sought to investigate SMA behaviors and risk factors among Chinese university students, and further explore the association between SMA practices and adverse drug events (ADEs). STUDY DESIGN Cross-sectional study. METHODS An online survey was conducted at Jiangsu University (JSU) in eastern China in July 2011 using a pretested questionnaire. RESULTS Out of 2608 website visitors, 1086 participated in the survey (response rate: 41.6%), 426 respondents were excluded for not being a JSU student or repeat participation, 660 (2.2% of JSU students) were included in analysis, and 316 students (47.9%) had a lifetime history of SMA. Among self-treated students, 43.5% believed that antibiotic was suitable for viral infections, 65.9% had more than one SMA episode in the previous year, 73.5% self-medicated with at least two different antibiotics, 57.1% and 64.4% changed antibiotic dosage and antibiotics during the course, respectively. Female gender, older age, and prior knowledge of antibiotics (PKA) were identified as independent risk factors of SMA. There was no difference between students with and without PKA regarding SMA frequency, use of polyantibiotics, and switching antibiotic dosage or antibiotics. ADEs happened to 13.3% of self-medicated students. Frequent change of dosage and simultaneous use of the same antibiotic with different names were independent risk practices associated with an ADE. CONCLUSIONS Our findings substantiate high SMA prevalence among Chinese university students. Older age and PKA are independent SMA risk factors common to Chinese university students and female gender is exclusive SMA risk factor for JSU students. Poor SMA practices are associated with ADEs. Strict regulations on antibiotic sales and public education reinforced by further health care reform are recommended.

Limited knowledge and practice of Chinese medical students regarding health-care associated infections

INTRODUCTION Health-care associated infections (HCAIs) occur worldwide and affect both patients and health-care workers (HCWs), including medical students. This study aimed to investigate HCAI risks associated with clinical medical students attending Shantou University Medical College (SUMC) and the effectiveness of their learning resources. METHODOLOGY Four cohorts (n = 272) of medical students participated in a questionnaire-based survey was done on (year 5 in the 5-year program and years 5 to 7 in the 7-year program) undergoing internship training in 14 teaching hospitals in Guangdong, China. RESULTS The mean overall score of the students was 52.54 ± 0.45 (mean ± SE). Students received fairly good scores in hand hygiene (77.57 ± 0.77) and HCAI source (63.16 ± 1.18); relatively weak scores in the isolation precautions (44.59 ± 0.55), HCW safety (45.59 ± 0.86), and personal protective equipment (57.64 ± 0.60); and the weakest scores in HCA-pathogen identification (27.44 ± 0.81). The year of education (r = 0.089, P = 0.144, n = 272) or internship placement (r = 0.077, P = 0.206, n = 272) had no significant influence on their level of knowledge. CONCLUSIONS This study demonstrates that medical students at SUMC have limited knowledge and practice regarding HCAI due to substantial deficiencies in their learning resources. Review of medical curricula, improvement in preclinical and clinical training, and surveillance and monitoring of practicing HCWs are urgently needed to minimize risk of HCAIs in patients and HCWs.

Pharmacopoeial quality of antimicrobial drugs in southern China.

Antimicrobial drugs are the most counterfeit or substandard drugs worldwide. The pharmacopoeial quality of these drugs in China is of special concern because China is the second producer, after India, of most counterfeit or substandard drugs in the global market. The antimicrobials circulating in China are produced by local, joint-venture, or foreign pharmaceuticals. There were 4875 local pharmaceutical manufacturers in China in 2013, most of which were smallsized or medium-sized. Although the central government aimed to minimise the number of pharmaceutical manufacturers and to improve drug quality by increasing the severity of punishment for forgery, the progress has been slow with only minor changes in the related policies and surveillance on pharmaceutical manufacturers and 414 840 pharmacies across China. Loose regulations and laws (eg, the maximum penalty of 1000 RMB [1 RMB≈0·1 GBP] for the sale of prescription drugs without prescription) greatly contribute to the great increase in non-prescription antimicrobial drugs and underline the problem of drug resistance in China. Moreover, storage conditions in domestic pharmacies are usually suboptimal with unknown effects on the pharmacopoeial quality of medicines. The reported prevalence of counterfeit or substandard medicines is 1–2% on the China Food and Drug Administration (CFDA) website; one available official report cites the prevalence of counterfeit or substandard antimicrobials in 2007 as 1·9%, which is much lower than the 22–38% prevalence reported in other low-income and middle-income countries. Therefore, in a crosssectional study, we independently investigated the pharmacopoeial quality of fi ve common antimicrobial drugs (amoxicillin, azithromycin, cefuroxime axetil, levofloxacin, and metronidazole) from community pharmacies in Shantou, southern China, with a population of 5·1 million. We selected the five antimicrobial drugs representing common antimicrobial c lasses—penici l l ins, macrolides, cephalosporins, quinolones, and imidazoles—because they were (1) commonly used in hospitals and community pharmacies, (2) sensitive to degrade under unsatisfi ed storage conditions, (3) frequently reported to have no active ingredient, and/or (4) included in the National Essential Drug List of China, as described previously. Of note, levofloxacin and cefuroxime axetil were first and third among the top 10 consumed antimicrobials in 360 hospitals in China during 2005–08. In this cross-sectional study (May– July, 2013), our study staff purchased 506 antimicrobial samples without prescriptions and without informing the purpose of purchase from 115 rural and urban community pharmacies, representing 4·1% of all community pharmacies in Shantou. We used stratifi ed random sampling by district (depending on the total numbers of pharmacies and populations in districts) to select the pharmacies, ensuring the coverage of all seven districts in Shantou. Following the Chinese Pharmacopeia (Version 2010), we validated the pharmacopoeial quality of the samples using high-performance liquid chromatography (HPLC) in the Bio-analytical Laboratory of Shantou University Medical College (Shantou, China). Reference standard antimicrobial drugs were purchased from the National Institutes for Food and Drug Control, China. Assays were conducted in triplicate runs for each sample, blinded to packaging, and mean value was reported as the active pharmaceutical ingredient (API) of each sample. An antimicrobial sample was regarded as poor quality if its actual amount of API was lower than 90% or higher than 110% of the labelled amount (except for metronidazole, for which the limits were <93% or >107%). A sample containing the wrong type of API or no API was considered counterfeit, on the basis of WHO’s definition of counterfeit medicines. We used a χ2 test, a t-test, and a ranksum test for the analyses through SPSS statistics (v17.0). Our results are reported according to the MEDQUARG guidelines where possible. The APIs of five antimicrobials are shown in table 1. The tested antimicrobial samples were made in the mainland China, Hong Kong, Japan, USA, and UK, and registered with CFDA. Of 506 samples, 77 (15%) failed to meet the Chinese Pharmacopeia standard limits in HPLC tests and 60 (78%) of these 77 samples had an API lower than the labelled amount (table 2). All the poor-quality antimicrobials were from the mainland China (table 2). The poorquality antimicrobials represented 65 (57%) of all 115 sampled pharmacies. The number of pharmaceutical manufacturers that produced the

Diagnostic Accuracy of Global Pharma Health Fund Minilab™ in Assessing Pharmacopoeial Quality of Antimicrobials

Abstract. Global Pharma Health Fund (GPHF) Minilab™, a semi-quantitative thin-layer chromatography (TLC)–based commercially available test kit, is widely used in drug quality surveillance globally, but its diagnostic accuracy is unclear. We investigated the diagnostic accuracy of Minilab system for antimicrobials, using high-performance liquid chromatography (HPLC) as reference standard. Following the Minilab protocols and the Pharmacopoeia of the People’s Republic of China protocols, Minilab-TLC and HPLC were used to test five common antimicrobials (506 batches) for relative concentration of active pharmaceutical ingredients. The prevalence of poor-quality antimicrobials determined, respectively, by Minilab TLC and HPLC was amoxicillin (0% versus 14.9%), azithromycin (0% versus 17.4%), cefuroxime axetil (14.3% versus 0%), levofloxacin (0% versus 3.0%), and metronidazole (0% versus 38.0%). The Minilab TLC had false-positive and false-negative detection rates of 2.6% (13/506) and 15.2% (77/506) accordingly, resulting in the following test characteristics: sensitivity 0%, specificity 97.0%, positive predictive value 0, negative predictive value 0.8, positive likelihood ratio 0, negative likelihood ratio 1.0, diagnostic odds ratio 0, and adjusted diagnostic odds ratio 0.2. This study demonstrates unsatisfying diagnostic accuracy of Minilab system in screening poor-quality antimicrobials of common use. Using Minilab as a stand-alone system for monitoring drug quality should be reconsidered.