Prevalence Of Panton-Valentine Leukocidin Gene Research Articles

Impact of human created environments in the pathogenic potential and antimicrobial resistance of staphylococci from wild neotropical primates in Brazil

The non-human primate (NHP) Leontopithecus rosalia is an endangered species native of Brazil and lives in forest fragments with different levels of contact with humans (natural, private and urban). Other NHPs – Callithrix spp. - were introduced by humans and co-exist and interact with the native species in these forests.To evaluate if living in or close to human-modified environments could constitute a risk for L. rosalia, we compared the prevalence, genetic background, antibiotic susceptibility and virulence gene content of staphylococci collected from the native and the introduced species from different forest fragments.We found that presence in human-dominated environments increased the colonization rate of L. rosalia with Mammaliicoccus sciuri (former Staphylococcus sciuri) from 18 % to 85 % (p = 0.0001) and of Callithrix spp with Staphylococcus aureus from 6 % to 100 % (p = 0.0001). According to molecular typing data obtained differences probably resulted from dissemination of these bacterial species from the invader NHP species and from humans. Changes in microbiota were paralleled by an increase in the prevalence of Panton-Valentine Leukocidin gene and in resistance to beta-lactams, macrolides and/or lincosamides as exposure to human environment increased. In particular, erythromycin resistance in S. aureus from Callithrix spp. increased from 0 % to 50 % and resistance rate to at least one antibiotic in coagulase-negative staphylococci species from L. rosalia increased from 13 % to 56 % (p = 0.0003).Our results showed that contact of native animal species with human-created environments increased the content of antimicrobial resistant and pathogenic bacteria on their commensal microbiota, which ultimately can impact on their health. ImportanceEndangered animal species are vulnerable to environmental alterations and human activities have been repeatedly identified as factors driving drastic changes in the natural landscape. It is extremely important to monitor changes in the environment surrounding protected species, because this could lead to early detection of any potential threats. In this study, we found that the contact of L. rosalia - a protected non-human primate from Brazil - with human environments is related to changes in their commensal microbiota. These included an increase in the number of pathogenic and antibiotic resistant bacteria, which have a higher potential to cause infections that are more difficult to treat. We provided evidence for the harmful impact human contact has on L. rosalia. Also, our results suggest that monitoring of commensal microbiota of protected animal species might be a useful way of sensing the risks of protected species to human exposure.

Epidemiological Study on the Prevalence of Staphylococcus aureus PVL Gene Among Healthy Community in Al- Karkh and Al -Rusaffa Districts Baghdad, Iraq

Five hundred nasal swabs were taken from normal medical staff and public in the city of Baghdad. Several identification parameters were used to recognize the bacterial isolates. S. aureus isolations form nasal swabs were identified using morphology and VITECK 2 system. Polymerase chain reaction (PCR) was employed to determine PVL (Panton–Valentine leukocidin ) gene in S. aureus. The data showed no significant evidence on the relationship between PVL gene presence and gender and age of the studied groups. There was no relation between the prevalence of PVL gene in the age groups of 21-30 years (p=0.328) and 31-40 years (p=0.682).
 The results showed that 38.4% and 37.5% S. aureus isolates were isolated from nurses working at Baghdad Teaching Hospital and AL-Yarmouk Teaching Hospital, respectively, while, doctors, pharmacists, and radiology staff were negative (0.00%).
 There was no significant difference between hospital staff and community in AL-Karkh (p=0.838) and in AL-Rusafa (p=0.118).

Prevalence of skin infections caused by Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureusinJapan, particularly in Ishigaki, Okinawa.

The prevalence of Panton-Valentine leukocidin gene (pvl)-positive community-acquired methicillin-resistant Staphylococcus aureus USA300 clone, which is designated as the ST8-staphylococcal cassette chromosome (SCC) mec type IV (ST8-IV) lineage, is a major public health concern worldwide. Thus, to elucidate the prevalence and characteristics of pvl-positive community-onset MRSA in Japan, we conducted a molecular epidemiological analysis for 854 S.aureus isolates obtained from outpatients with skin infections during 2013 and 2014. The isolation rate of MRSA was 25.6% (219 isolates), and the ratio of pvl-positive MRSA was 13.2% (29 isolates). Notably, the proportion (93.8%) of pvl-positive isolates was particularly high among MRSA isolates from Ishigaki island in Okinawa. Pulsed-field gel electrophoresis and multilocus sequence typing showed that the pulsotype C isolates (11 isolates) were typical USA300 clones with arginine catabolic mobile element (ACME) type I-CC8-IV lineages and prevalent on the main island of Japan (Honshu). Pulsotypes A (11 isolates) and B (four isolates) consisted of ACME-negative CC8-IV clones and were specific for Ishigaki island. Both USA300 and Okinawa-Ishigaki specific clones were associated with deep-seated skin infections, such as furuncle and cellulitis. Pulsotypes D (two isolates) and E (one isolate) were ACME-negative clonal complex (CC) 59-IV clones and were related to superficial skin infections, such as impetigo. Our findings revealed that pvl-positive MRSA associated with deep-seated skin infections are spreading in Japanese communities, particularly in Ishigaki, Okinawa.

Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infection and the molecular characteristics of MRSA bacteraemia over a two-year period in a tertiary teaching hospital in Malaysia

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is an established pathogen that causes hospital- and community-acquired infections worldwide. The prevalence rate of MRSA infections were reported to be the highest in Asia. As there is limited epidemiological study being done in Malaysia, this study aimed to determine the prevalence of MRSA infection and the molecular characteristics of MRSA bacteraemia.MethodsTwo hundred and nine MRSA strains from year 2011 to 2012 were collected from a tertiary teaching hospital in Malaysia. The strains were characterized by antimicrobial susceptibility testing, staphylococcal cassette chromosome mec (SCCmec) typing, detection of Panton-Valentine leukocidin (PVL) gene, multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Patient’s demographic and clinical data were collected and correlated with molecular data by statistical analysis.ResultsMale gender and patient >50 years of age (p < 0.0001) were significantly associated with the increased risk of MRSA acquisition. Fifty-nine percent of MRSA strains were HA-MRSA that carried SCCmec type II, III, IV and V while 31% were CA-MRSA strains with SCCmec III, IV and V. The prevalence of PVL gene among 2011 MRSA strains was 5.3% and no PVL gene was detected in 2012 MRSA strains. All of the strains were sensitive to vancomycin. However, vancomycin MIC creep phenomenon was demonstrated by the increased number of MRSA strains with MIC ≥1.5 μg/mL (p = 0.008) between 2011 and 2012. Skin disease (p = 0.034) and SCCmec type III (p = 0.0001) were found to be significantly associated with high vancomycin MIC. Forty-four percent of MRSA strains from blood, were further subtyped by MLST and PFGE. Most of the bacteraemia cases were primary bacteraemia and the common comorbidities were diabetes, hypertension and chronic kidney disease. The predominant pulsotype was pulsotype C exhibited by SCCmec III-ST239. This is a first study in Malaysia that reported the occurrence of MRSA clones such as SCCmec V-ST5, untypeable-ST508, SCCmec IV-ST1 and SCCmec IV-ST1137.ConclusionsSCCmec type III remained predominant among the MRSA strains in this hospital. The occurrence of SCCmec IV and V among hospital strains and the presence of SCCmec III in CA-MRSA strains are increasing. MRSA strains causing bacteraemia over the two-year study period were found to be genetically diverse.

Molecular Detection of Panton-Valentine Leukocidin (PVL) Toxins in Clinical Isolates of Staphylococcus aureus from Maitama District Hospital, Abuja, Nigeria

Pathogenic Staphylococcus aureus is the most frequently isolated Gram positive bacterium from clinical specimens; and it is among the leading cause of infection in man. S. aureus has gained significant interest in recent years as an important nosocomial pathogen – owing to its multidrug resistant nature which is associated to several virulence factors of the organism including Panton-valentine leukocidin (PVL). PVL is part of the toxins produced by pathogenic S. aureus – which help the organism to exacerbate their pathogenicity/virulence in the phase of an infection. This study evaluated the prevalence of PVL-positive S. aureus from clinical specimens – owing to the dearth of information on this subject matter in Nigeria. Out of the 118 non-consecutive S. aureus isolates employed for this study, only 56 isolates were biochemically confirmed as pathogenic S. aureus. The antibiogram showed that the S. aureus isolates were most susceptible to gentamicin, vancomycin, ciprofloxacin, erythromycin and linezolid. However, they were highly resistant to the cephamycin, cefoxitin (82.1%). The S. aureus isolates also showed reduced susceptibility to tigecycline (71.4%), clindamycin (66.1%), chloramphenicol (48.2%), amoxicillin-clavulanic acid (53.6%) and sulphamethoxazole-trimethoprim (48.2%). The prevalence of PVL genes in this study was 10.7%. Only 6 isolates of S. aureus (10.7%) were confirmed by PCR to harbour the PVL genes; and these S. aureus isolates were from wound samples, abscess and urine samples. The occurrence of pathogenic S. aureus harbouring drug resistant genes such as PVL genes in the hospital environment pose serious health and therapeutic challenges especially in choosing antimicrobial therapy for treatment. S. aureus isolates with PVL genes could also disseminate with high propensity within the hospital environment; and this could result in the outbreak of nosocomial infections. Continues antibiotic stewardship in our hospitals will help in the control and prevention of the emergence and dissemination of drug-resistant microbes in both the community and hospital environment.

Molecular characteristics of community-acquired, methicillinresistantStaphylococcus aureusisolated from Chinese children

The aim of this study was to investigate the molecular characteristics of community-acquired, methicillin-resistant Staphylococcus aureus (CA-MRSA) isolates from Chinese children. Ninety-nine isolates were collected from eight hospitals, and analyzed by multilocus sequence typing, staphylococcal chromosomal cassette mec (SCCmec) type, and spa typing. The Panton-Valentine leukocidin (PVL) gene was also detected. Overall, 14 sequence types (STs) were obtained, and ST59 (58.6%) was found to be the most prevalent, followed by ST1 (8%) and ST338 (8%). We also first registered the new ST1409. SCCmec type IV was the most predominant type at 67.7%, followed by SCCmec type V at 32.3%. SCCmec subtypes IVa, IVc, and IVg were found among the SCCmec type IV strains. Twenty-one spa types were also identified. Four new spa types were found by synchronization with the Ridom SpaServer and referring to the website (http://www.SeqNet.org). ST59-MRSA-IVa with t437 accounted for 40.4% of occurrences, making it the most prevalent clone. The prevalence of PVL genes was 58.6%, and multidrug resistance was observed in 95% of all isolates. This result indicates that CA-MRSA isolates in Chinese children are largely associated with the ST59-MRSA-IV clone, and that the predominant clones of CA-MRSA are spread all over the country.

Molecular characteristics of community-acquired, methicillin-resistantStaphylococcus aureusisolated from Chinese children

The aim of this study was to investigate the molecular characteristics of community-acquired, methicillin-resistant Staphylococcus aureus (CA-MRSA) isolates from Chinese children. Ninety-nine isolates were collected from eight hospitals, and analyzed by multilocus sequence typing, staphylococcal chromosomal cassette mec (SCCmec) type, and spa typing. The Panton-Valentine leukocidin (PVL) gene was also detected. Overall, 14 sequence types (STs) were obtained, and ST59 (58.6%) was found to be the most prevalent, followed by ST1 (8%) and ST338 (8%). We also first registered the new ST1409. SCCmec type IV was the most predominant type at 67.7%, followed by SCCmec type V at 32.3%. SCCmec subtypes IVa, IVc, and IVg were found among the SCCmec type IV strains. Twenty-one spa types were also identified. Four new spa types were found by synchronization with the Ridom SpaServer and referring to the website (http://www.SeqNet.org). ST59-MRSA-IVa with t437 accounted for 40.4% of occurrences, making it the most prevalent clone. The prevalence of PVL genes was 58.6%, and multidrug resistance was observed in 95% of all isolates. This result indicates that CA-MRSA isolates in Chinese children are largely associated with the ST59-MRSA-IV clone, and that the predominant clones of CA-MRSA are spread all over the country.

Prevalence of Panton-Valentine leukocidin genes in methicillin-resistant Staphylococcus aureus isolates phenotypically consistent with community-acquired MRSA, 1999–2007, Vienna General Hospital

The purpose of this study was to investigate methicillin-resistant Staphylococcus aureus (MRSA) isolates with antibiotic resistance restricted to beta-lactam antibiotics and variable resistance to fusidic acid for the presence of Panton-Valentine leukocidin (PVL) genes. Our data show that the selected resistance pattern is found rarely among MRSA isolates in our hospital, but it appears that this phenotype consistent with typical community-acquired (ca) MRSA is indicative of PVL-positive MRSA.