Exfoliative Toxin Research Articles

Molecular Evaluation of Traditional Chicken Farm-Associated Bioaerosols for Methicillin-Resistant Staphylococcus aureus Shedding.

The outbreak of airborne pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA) through bioaerosol, and their molecular characterization around domestic poultry farming areas, was not completely understood. This imposes risk of a MRSA-associated health threat for the relevant livestock food production units. To address this issue, the present study investigated the role of bioaerosol in transmitting MRSA strains in poultry house settings by combining molecular typing, phylogenetic classification, antibiotic susceptibility, and virulence gene distribution patterns. The present study highlights that all 18 bioaerosol and stool samples collected were MRSA positive, with a unique set of virulence factors. Out of 57 isolated MRSA isolates, 68.4% and 19.3% consisted of SCCmec I and IV elements, respectively, which are commonly linked with hospital-acquired and livestock-associated MRSA strains. It is worth noting that the exfoliative toxin eta and etb genes were carried by 100% and 70.2% of all isolates, respectively. Only 17.5% of strains showed the presence of enterotoxin entC. These MRSA isolates were resistant to chloramphenicol (C), ciprofloxacin (CIP), clindamycin (DA), erythromycin (E), and tetracycline (T), signifying their multi-drug resistance traits. A cluster of phylogenetic analysis described that 80.7% and 15.8% of total isolates belonged to Staphylococcus aureus protein A (spa) type t002 and t548. Whereas 3.5% were reflected as a new spa type. Additionally, as per the chi-squared test score value, these two spa types (t002 and t548) have a distribution correlation with HA-MRSA and LA-MRSA in all the samples (p < 0.005, chi-squared test; degree of freedom = 1). Ultimately, this study highlights the prevalence of MRSA colonization in the conventional poultry farm environment, showing the risk of bioaerosol transmission, which needs epidemiological attention and prevention strategies.

Virulence Factor Genes and Antimicrobial Susceptibility of Staphylococcus aureus Strains Isolated from Blood and Chronic Wounds.

Staphylococcus aureus is one of the predominant bacteria isolated from skin and soft tissue infections and a common cause of bloodstream infections. The aim of this study was to compare the rate of resistance to various antimicrobial agents and virulence patterns in a total of 200 S. aureus strains isolated from patients with bacteremia and chronic wounds. Disk diffusion assay and in the case of vancomycin and teicoplanin-microdilution assay, were performed to study the antimicrobial susceptibility of the isolates. The prevalence of genes encoding six enterotoxins, two exfoliative toxins, the Panton–Valentine leukocidin and the toxic shock syndrome toxin was determined by PCR. Of the 100 blood strains tested, the highest percentage (85.0%, 31.0%, and 29.0%) were resistant to benzylpenicillin, erythromycin and clindamycin, respectively. Out of the 100 chronic wound strains, the highest percentage (86.0%, 32.0%, 31.0%, 31.0%, 30.0%, and 29.0%) were confirmed as resistant to benzylpenicillin, tobramycin, amikacin, norfloxacin, erythromycin, and clindamycin, respectively. A significantly higher prevalence of resistance to amikacin, gentamicin, and tobramycin was noted in strains obtained from chronic wounds. Moreover, a significant difference in the distribution of sea and sei genes was found. These genes were detected in 6.0%, 46.0% of blood strains and in 19.0%, and 61.0% of wound strains, respectively. Our results suggest that S. aureus strains obtained from chronic wounds seem to be more often resistant to antibiotics and harbor more virulence genes compared to strains isolated from blood.

Detection and molecular characterisation of methicillin-resistant Staphylococcus aureus isolated from raw meat in the retail market

This study aimed to detect and characterise methicillin-resistant Staphylococcus aureus (MRSA) from retail meat in the Czech Republic. Isolates were identified by PCR detection of the S. aureus-specific fragment Sa442 and mecA gene. spa typing, MLST, detection of genes encoding staphylococcal enterotoxins, Panton-Valentine leukocidin (pvl), exfoliative toxins A and B (eta and etb), toxic shock syndrome toxin (tst) and staphylokinase (sak), detection of φSa3 prophage and antimicrobial susceptibility testing were performed. Of 65 raw meat samples examined (poultry, beef, pork and rabbit), 23 (35.4%) were positive for MRSA. Twelve positive samples originated from poultry (12/33; 36.4%), while the remaining eleven came from pork (9/9; 100%) and pork/beef mixed minced meat (2/5; 40.0%). Eight spa types belonging to five different sequence types (STs) were identified. ST398 was the most frequent (28/36; 77.8%), presenting spa types t011, t034, t2576, t4132, t588 and t899. Other livestock-associated MRSA STs (ST9-t899, ST5-t002, ST692-t8646 or the newly described ST4034-t899) were also sporadically identified. In seven isolates (19.4%), one or more staphylococcal enterotoxin genes were detected, with sea, seg and sei prevailing. Three isolates from turkey [ST398-t899 (n=2) and ST398-t011] harboured the sak gene, and the latter also harboured the sea gene. Seven isolates from poultry harboured the φSa3 prophage and were resistant to tetracycline. Specific kinds of meat appear to be a possible source of MRSA, although the risk to humans is hard to define. Therefore, surveillance of MRSA in meat as well as hygienic practices should be improved.

Fatal staphylococcal scalded skin syndrome in a newborn.

Staphylococcal scalded skin syndrome (SSSS) is characterized by superficial blistering of the skin caused by exfoliative toxins of Staphylococcus aureus. SSSS predominantly affects children under five-year-old. We present a case of a 30-day-old female infant who developed circumscribed flaccid blisters within erythematous skin, with positive Nikolsky’s sign, without mucosal involvement. The ruptured blisters resulted in desquamation and scalded skin, then extending rapidly. The diagnosis of SSSS was achieved clinically and the patient was treated with intravenous cloxacillin. However, despite the given treatment in limited resources setting, the patient died due to sepsis. This case report highlights the difficulties in treating SSSS in limited-facilities hospital setting and underlines its life-threatening complications, such as sepsis. It is also aimed at raising awareness of SSSS as a possible differential diagnosis of superficial blistering and exfoliative skin disorders, especially in children population.

Emergence of a mupirocin-resistant, methicillin-susceptible Staphylococcus aureus clone associated with skin and soft tissue infections in Greece

BackgroundStaphylococcus aureus causes various infections, including skin and soft tissue infections (SSTIs). In this study, methicillin-susceptible S. aureus (MSSA) from SSTIs among patients in three tertiary-care hospitals in Greece were studied in terms of antimicrobial resistance, clonal distribution, toxin and adhesin genes carriage.ResultsDuring a five-year period (2014–2018), 6145 S. aureus were recovered from 13,244 patients with SSTIs and tested for antimicrobial susceptibility. MSSA were 4806 (78.21 %) including 1484 isolates with mupirocin minimum inhibitory concentration (MIC) > 64 mg/L (30.88 %). Two hundred and sixty representative mupirocin-resistant MSSA were analyzed for genes encoding Panton-Valentine leukocidin (PVL, lukS/lukF-PV), exfoliative toxins (eta, etb), adhesin FnbA (fnbA) and resistance genes mupA (high-level resistance to mupirocin), fusB (fusidic acid), aminoglycosides’ modifying enzymes, ermA, ermC and msrA (macrolides/lincosamides) by PCRs. Strains were classified into clones by PFGE and MLST.All mupirocin-resistant MSSA were penicillin-resistant; 92.7 % expressed resistance to fusidic acid and 88.9 % to tobramycin. All 260 molecularly analyzed isolates were mupA-positive; all fusidic acid-resistant (241/260) carried fusB whereas, the tobramycin-resistant ones (230), ant(4′)-Ia. The majority carried eta (93.85 %), etb (98.08 %) and fnbA (88.85 %). PFGE typing revealed a mostly unvarying population; 260 MSSA were grouped into three types. One major eta/etb-positive clone comprising of 258/260 strains (99.2 %), PFGE type 1, was classified as ST121, including nine strains co-carrying PVL. Another PVL-positive strain was identified as ST1, and one toxins-negative as ST21.ConclusionsA mupirocin-resistant MSSA clone, ST121, carrying resistance, exfoliative toxins and adhesin genes, was spread and predominated in SSTIs from patients in Greece during the five-year studied period.

Staphylococcal-Scalded Skin Syndrome

Staphylococcal-scalded skin syndrome (SSSS) is also known as Ritter's disease. The symptoms produced by the strains of staphylococcus occur due to exfoliative toxins. Here, we have presented a case series of four children aged &lt;2 years, who were admitted in MGM Medical College and Hospital, Aurangabad, for fever in association with superficial fluid-filled lesions leaving large denuded areas behind Nikolsky's sign – positive. The mucosal area was spared. Blood culture served as diagnostic test, besides clinical history and examination. All the children were treated with cephalosporin and responded well. Hydration was maintained with topical mupirocin over the eroded areas. A high degree of suspicion has to be there for SSSS. We emphasize the importance of interdisciplinary management, association with dermatologist, pediatrics, and plastic surgeon for better outcome. Although considered rare, we came across four cases of SSSS with classical presentation.

First Molecular Characterization of Siphoviridae-Like Bacteriophages Infecting Staphylococcus hyicus in a Case of Exudative Epidermitis.

Exudative epidermitis (EE), also known as greasy pig disease, is one of the most frequent skin diseases affecting piglets. Zoonotic infections in human occur. EE is primarily caused by virulent strains of Staphylococcus (S.) hyicus. Generally, antibiotic treatment of this pathogen is prone to decreasing success, due to the incremental development of multiple resistances of bacteria against antibiotics. Once approved, bacteriophages might offer interesting alternatives for environmental sanitation or individualized treatment, subject to the absence of virulence and antimicrobial resistance genes. However, genetic characterization of bacteriophages for S. hyicus has, so far, been missing. Therefore, we investigated a piglet raising farm with a stock problem due to EE. We isolated eleven phages from the environment and wash water of piglets diagnosed with the causative agent of EE, i.e., S. hyicus. The phages were morphologically characterized by electron microscopy, where they appeared Siphoviridae-like. The genomes of two phages were sequenced on a MiSeq instrument (Illumina), resulting in the identification of a new virulent phage, PITT-1 (PMBT8), and a temperate phage, PITT-5 (PMBT9). Sequencing of three host bacteria (S. hyicus) from one single farm revealed the presence of two different strains with genes coding for two different exfoliative toxin genes, i.e., exhA (2 strains) and exhC (1 strain). The exhC-positive S. hyicus strain was only weakly lysed by most lytic phages. The occurrence of different virulent S. hyicus strains in the same outbreak limits the prospects for successful phage treatment and argues for the simultaneous use of multiple and different phages attacking the same host.

Molecular and Anti-Microbial Resistance (AMR) Profiling of Methicillin-Resistant Staphylococcus aureus (MRSA) from Hospital and Long-Term Care Facilities (LTCF) Environment.

To provide evidence of the cross-contamination of emerging pathogenic microbes in a local network between long-term care facilities (LTCFs) and hospitals, this study emphasizes the molecular typing, the prevalence of virulence genes, and the antibiotic resistance pattern of methicillin-resistant Staphylococcus aureus. MRSA isolates were characterized from 246 samples collected from LTCFs, medical tubes of LTCF residents, and hospital environments of two cities, Chiayi and Changhua. Species identification, molecular characterization, and drug resistance analysis were performed. Hospital environments had a higher MRSA detection rate than that of LTCF environments, where moist samples are a hotspot of MRSA habitats, including tube samples from LTCF residents. All MRSA isolates in this study carried the exfoliative toxin eta gene (100%). The majority of MRSA isolates were resistant to erythromycin (76.7%), gentamicin (60%), and ciprofloxacin (55%). The percentage of multidrug-resistant MRSA isolates was approximately 50%. The enterobacterial repetitive intergenic consensus polymerase chain reaction results showed that 18 MRSA isolates belonged to a specific cluster. This implied that genetically similar isolates were spread between hospitals and LTCFs in Changhua city. This study highlights the threat to the health of LTCFs’ residents posed by hospital contact with MRSA.

Staphylococcal Scalded Skin Syndrome in Healthy Infant

Staphylococcal scalded skin syndrome (SSSS) describes a spectrum of superficial blistering skin disorders caused by the exfoliative toxins of Staphylococcus aureus that originates from a focus of infection that may be a purulent conjunctivitis, otitis media, or occult nasopharyngeal infection. It usually begins with fever, irritability, and a generalized, paint, orange-red, macular erythema with cutaneous tenderness, and the rash progress from scarlatiniform to a blistering eruption in 24 to 48 hours. A diagnosis must distinguish SSSS from other skin diseases, such as toxic epidermal necrolysis, epidermolysis bullosa, bullous erythema multiforme, Streptococcal impetigo or listeriosis and thermal or chemical burns, all of which can manifest with similar symptoms. The prognosis of SSSS in children who are appropriately treated is good, with a mortality of less than 5%. A case was a three moths old boy hospitalized in Pediatric ward M. Djamil hospital with chief complain redness and peeling of the skin since 2 days before hospitalized. Culture of the skin, eyes and nose was Staphylococcus aureus , and patients was given ampicillin and gentamycin for seven days.

Molecular Interactions of Cyanidin-3-glucoside with Bacterial Proteins Modulate the Virulence of Selected Pathogens in Caenorhabditis elegans

Anthocyanins are plant pigments known for their radical scavenging activity. However, the current understanding of the effects of anthocyanins in bacterial infection is limited to crude extracts. Additionally, most studies about cyanidin-3-glucoside (C3G), an anthocyanin compound from the cyanidin class, were limited to in vitro experiments. This paper investigated the protective mechanism of C3G against selected pathogens, namely Staphylococcus aureus (S. aureus), Enterococcus faecalis (E. faecalis), Klebsiella pneumoniae (K. pneumoniae), and Proteus mirabilis (P. mirabilis) using Caenorhabditis elegans (C. elegans) as the infection model. The nematodes were supplemented with varying sublethal concentrations of C3G every day after hatching. Besides, the concentrations of C3G used exhibit no bacterial growth suppression against the pathogens. The nematodes transferred to different plates were flooded with varying bacteria. The number of surviving worms were counted every day until all worms were deceased. To hypothesize the protective mechanism of C3G, its 3D structure was docked in the crystal structures of the different proteins produced by each pathogen. These protein molecules represent their virulence factors, which are available in the Protein Data Bank. The docked crystal structures were evaluated for their binding energies and binding interactions. Results show that C3G rescues C. elegans against S. aureus but not from E. faecalis, despite both are gram-positive. This observation is similar to the gram-negative pathogens where C. elegans were protected from P. mirabilis treatment but not against K. pneumoniae. Consistently, the docked crystal structures of C3G reveal to have a high binding affinity with amidohydrolase and exfoliative toxin A, which are virulence factors of P. mirabilis and S. aureus, respectively. These findings suggest that the protective mechanism of C3G against pathogens may influence the virulence factors of certain bacteria only.

The First Report of a Methicillin-Resistant Staphylococcus aureus Isolate Harboring Type IV SCCmec in Thailand.

Methicillin-resistant Staphylococcus aureus (MRSA) is mostly found in Thailand in the hospital as a nosocomial pathogen. This study aimed to report the genetic characterization of a clinical community-acquired MRSA (CA-MRSA) isolate collected from hospitalized patients in Thailand. Among 26 MRSA isolates, S. aureus no. S17 preliminarily displayed the presence of a staphylococcal cassette chromosome mec (SCCmec) type IV pattern. The bacterial genomic DNA was subjected to whole-genome sequencing. Panton–Valentine leukocidin (PVL) production, virulence toxins, and antibiotic resistance genes were identified, and multi-locus sequence typing (MLST) and spa typing were performed. The strain was matched by sequence to MLST type 2885 and spa type t13880. This strain carried type IV SCCmec with no PVL production. Five acquired antimicrobial resistance genes, namely blaZ, mecA, Inu(A), tet(K), and dfrG conferring resistance to β-lactams, lincosamides, tetracycline, and trimethoprim, were identified. The detected toxins were exfoliative toxin A, gamma-hemolysin, leukocidin D, and leukocidin E. Moreover, there were differences in seven regions in CR-MRSA no. S17 compared to CA-MRSA type 300. In summary, we have reported the ST2885-SCCmec IV CA-MRSA clinical strain in Thailand for the first time, highlighting the problem of methicillin resistance in community settings and the consideration in choosing appropriate antibiotic therapy.

Multidrug resistant staphylococci isolated from pigs with exudative epidermitis in North eastern Region of India.

Exudative epidermatitis or greasy pig disease (GPD) is a contagious disease of pig and endemic worldwide caused by toxigenic strains under genus Staphylococcus. The present study reported an outbreak of GPD in Champhai district of Mizoram adjoining to the southern border of Myanmar. A total of 60 samples were collected from 22 clinically affected animals and processed for isolation and identification of Staphylococcus spp. All the isolates were subjected to antimicrobial sensitivity assay, biofilm production assay and detection of virulence genes, biofilm genes and mec genes followed by cloning and sequencing for phylogenetic analysis. A total of 44 staphylococci belonged to four species (S. sciuri, S. aureus,S. lentus, and S. hyicus) were isolated. Majority of the isolates were multidrug resistant with maximum resistance against ampicillin, penicillin including vancomycin. None of the S. hyicus isolates was methicillin resistant (MRSH) but 66·67% isolates were MRSA. By PCR, mecA gene was detected in S. aureus (n=2), S. sciuri (n=4) and S. lentus (n=3). Biofilm associated gene icaD was detected in S. aureus (n=3), S. sciuri (n=5), S. hyicus (n=4) and S. lentus (n=6). The exfoliative toxin genes (ehxB, shetA and tsst1) were detected in S. hyicus (n=3) and S. aureus (n=1) isolates. All the isolates were closely related with the isolates from pigs of China, Germany, Japan and USA. The pathogens might be transmitted through illegal migration of pigs from Myanmar to India.

Whole genome sequencing of coagulase positive staphylococci from a dog-and-owner screening survey

BackgroundStaphylococcus aureus and S. pseudintermedius are the two most common coagulase positive staphylococci (CPS). S. aureus is more prevalent among humans, whereas S. pseudintermedius is more commonly isolated from dogs, however, both can cause various community and hospital acquired diseases in humans.MethodsIn the current study we screened 102 dogs and 84 owners in Hungary. We tested the antibiotic susceptibility of the strains and in order to get a better picture of the clonal relationship of the strains, we used pulsed-field gel electrophoresis. In addition, three pairs of isolates with identical PFGE patterns were whole genome sequenced, MLST and spa types were established.ResultsCarriage rate of S. aureus was 23.8% in humans and 4.9% in dogs and two cases of co-carriage were found among dogs and owners. S. pseudintermedius carriage rate was 2.4% and 34.3%, respectively, with only one co-carriage. The isolates were generally rather susceptible to the tested antibiotics, but high tetracycline resistance of S. pseudintermedius strains was noted. The co-carried isolates shared almost the same resistance genes (including tet(K), bla(Z), norA, mepR, lmrS, fosB) and virulence gene pattern. Apart from the common staphylococcal enzymes and cytotoxins, we found enterotoxins and exfoliative toxins as well. The two S. aureus pairs belonged to ST45-t630, ST45-t671 and ST15-t084, ST15-t084, respectively. The co-carried S. pseudintermedius isolates shared the same housekeeping gene alleles determining a novel sequence type ST1685.ConclusionsBased on the genomic data, dog-owner co-carried strains displayed only insignificant differences therefore provided evidence for potential human-to-dog and dog-to-human transmission.

Antimicrobial Resistance and Molecular Analysis of Staphylococcus aureus in Staphylococcal Scalded Skin Syndrome among Children in Korea.

BackgroundStaphylococcal scalded skin syndrome (SSSS) is a skin disease characterized by blistering and desquamation caused by exfoliative toxins (ETs) of Staphylococcus aureus (S. aureus). Although many countries show predominance of methicillin-susceptible S. aureus (MSSA), cases of methicillin-resistant S. aureus (MRSA) have been reported.MethodsTwenty-six children aged <15 years diagnosed with SSSS from January 2010 to December 2017 from three hospitals were included. S. aureus isolates from cases were analyzed for multilocus sequence types and ETs. Medical records were reviewed for clinical characteristics, treatment, and antimicrobial susceptibility patterns of S. aureus.ResultsAmong the 26 cases, mean age was 2.3 years. According to skin manifestations patients were classified as generalized (n = 10, 38.5%), intermediate (n = 11, 42.3%), and abortive (n = 5, 19.2%). Among all cases, 96.2% (25/26) were due to MRSA and the macrolide-resistance rate was 92.3% (24/26). ST89 (n = 21, 80.8%) was the most prevalent clone, followed by single clones of ST1, ST5, ST72, ST121, and ST1507. The eta gene was detected in one (3.8%) isolate which was MSSA. The etb gene was detected in 14 (53.8%) isolates, all of which were ST89. Nafcillin or first-generation cephalosporin was most commonly prescribed (n=20, 76.9%). Vancomycin was administered in four patients (15.4%) and clindamycin in nine patients (34.6%). Among MRSA cases, there was no difference in duration of treatment when comparing the use of antimicrobials to which the causative bacteria were susceptible or non-susceptible (9.75 vs. 8.07 days, P > 0.05).ConclusionS. aureus isolated from children with SSSS in Korea demonstrated a high prevalence of methicillin-resistant ST89 clones that harbored the etb gene. The predominance of MRSA suggests that antibiotics to which MRSA are susceptible may be considered for empirical antibiotic treatment in children with SSSS in Korea. Further studies on the role and effectiveness of systemic antibiotics in SSSS are warranted.

A case report on Staphylococcal Scalded Skin Syndrome in a 3 year old: Clinical diagnosis and management

Staphylococcal-scalded skin syndrome (SSSS) is a blistering skin disorder which is considered as a pediatric emergency. This life-threatening syndrome is caused by Staphylococcal exfoliative toxins produced by Staphylococcus aureus. Although it can affect any age group, children below 5 years of age are at utmost risk. The specific antibodies to exotoxins and increased exotoxin clearance, minimize the frequency of SSSS in adults. Mortality in infancy is low (4%) and is less than 10 % in children but is between 40% and 63% in adults. Clinical features of SSSS may range from a few localized blisters to generalized desquamation covering the entire body. The histopathological evaluation of the skin biopsy helps in the definitive diagnosis of SSSS. Here we present a case of a 3 year old female child with low grade fever associated with erythematous rashes all over the body and severe itching. A clinical diagnosis of Staphylococcal Scalded Skin Syndrome (SSSS) was made. With appropriate treatment using intravenous Flucloxacillin and supportive care, the child’s symptoms were completely resolved within a week.

High-risk ST772-MRSA lineage in South Asia: potential for global dissemination

Background: Methicillin resistant Staphylococcus aureus (MRSA) is a clinically important pathogen with an abundance of virulence factors and multi-drug resistance, that are essential for survival within host. In recent decades, a community-acquired lineage, ST772-MRSA are being frequently reported cause of hospital-onset infections and outbreak. ST772-MRSA is currently circulating in South Asia, Australia and Europe. We hypothesis that the presence of multiple resistance determinants in ST772-MRSA, is the driver for potential adaptation and evolution. Genome-wide association study was conducted to understand the evolutionary events within ST772-MRSA and propensity for dissemination. Methods and materials: Whole genome sequencing was performed for ST772-MRSA (n = 33), isolated from blood culture during 2013-2018. Global collection ST772 S. aureus genome (n = 120) were retrieved from National Center for Biotechnology Information (NCBI) and European Nucleotide Archive (ENA) databases. Core genome alignment and variant calling analysis were carried out using parsnp and snippy pipeline respectively. Divergence and evolution of ST772 S. aureus were estimated using phylogenetic BEAST analysis. Results: ST772-MRSA was emerged in the early 1970s. In this lineage, mecA gene was identified on a short variant (5C2) or composite (5C2&5) SCCmec V element. Among the investigated genome, 90% carried Panton Valentine leukocicidin (PVL) toxin, which is encoded by the prophage Φ-IND772PVL. vSaα, vSaβ and vSaγ pathogenicity islands carrying exotoxins, enterotoxin gene cluster and exfoliative toxin were identified on all ST772-MRSA genome. Mutation in parC (S80Y) and gyrA (S82L), contributed for quinolone resistance in 72% of the genome. A copy of dfrA gene, encoding for trimethoprim resistance was identified on all the core genome. An integrated resistance plasmid (IRP) containing resistant determinants for beta-lactam (blaZ), aminoglycosides (aphA3-sat-aadE), macrolide (msrA, mphC), and bacitracin (bacA, bacB) was found in all MRSA genome. Another landmark event, is the acquisition of IRP, in the early 1990s, resulted in a highly distinct uniform clade comprised of multi-drug resistant variant. Most of this variant mediated intercontinental transmission is typically associated with travel from South Asia. Conclusion: Acquisition of IRP contributed for the emergence of ST772-MRSA lineage, as a multi-drug resistant variant. Genetic changes associated with the adaptation and increasing multi-drug resistance in ST772-MRSA, represents the potential threat for global dissemination.

Staphylococcal scalded skin syndrome: An epidemiological and clinical review of 84 cases.

Staphylococcal scalded skin syndrome (SSSS) is a toxin-mediated, blistering skin disorder that mainly affects infants and children. There is limited literature regarding pediatric SSSS. The purpose of this study was to describe the epidemiology, clinical features, and management of pediatric SSSS. Retrospective cohort study of pediatric patients with a clinical diagnosis of SSSS seen at the Hospital for Sick Children in Toronto, Ontario, Canada, from January 1994 to March 2016. We included 84 patients with a clinical diagnosis of SSSS; 49/84 (58%) were male. Mean age of diagnosis was 3.1±2.4years. All patients presented with erythema and exfoliation, while 64/84 (76%) presented with vesicles/ bullae. Skin tenderness was the most common symptom, present in 68/84 (81%) subjects. Staphylococcus aureus was more commonly isolated from periorificial cultures than from bullae. Mean hospitalization was 4.7±2.3days. No difference was found in admission duration between children receiving clindamycin and those that did not (3.6±2.2 vs 3.9±2.34days, P=.63). Skin debridement was the only risk factor leading to more complications and prolonged hospitalization (P=.03). Severe complications were seen in 4 (5%) cases, and no fatalities were observed. Healthcare providers should be aware of SSSS and consider it in the differential diagnosis of infants and children with new onset erythema, exfoliation, and/or vesiculation. Suspected culprit pathogens were more often obtained from periorificial swabs; however, these isolates were not tested for exfoliative toxin to confirm causality. Antibiotic treatment should be guided by sensitivity testing. Addition of clindamycin as an anti-toxin agent had no effect on the duration of hospitalization, and this should be further investigated. Surgical debridement of the skin in patients with SSSS should be discouraged.

Presence of egc-positive major clones ST 45, 30 and 22 among methicillin-resistant and\xa0methicillin-susceptible oral Staphylococcusaureus strains

The oral cavity may comprise a significant reservoir for Staphylococcus aureus but the data on molecular epidemiology and clonal distribution of oral strains are really scarce. This study aimed to evaluate the clonal relatedness in S. aureus isolated from oral cavity and their relationship with carriage of virulence genes, and antimicrobial resistance profiles. A total of 139 oral S. aureus isolates were obtained from 2327 analysed oral samples of dental patients. Antimicrobial susceptibility testing was performed. Isolates were characterized using protein A gene (spa) typing, spa-CC clonal complexes, toxin genes and SCCmec typing for MRSA. High resistance rates for penicillin, tetracycline and gentamicin were detected, respectively 58.3%, 42.4%, and 35.2%. Twelve (8.6%) S. aureus isolates were identified as MRSA. All of MRSA isolates were mecA-positive and mecC-negative. SCCmec IV was the most common type (66.7%), which was typical for community-acquired MRSA (CA-MRSA). Overall, the enterotoxin gene cluster (egc) was the most frequent detected virulence factor (44.9%), both in MSSA and MRSA isolates. Presence of genes encoding for the enterotoxins (sea, seb, sec, seh, sek), exfoliative toxin A (eta), and toxic shock syndrome toxin-1 (tst) was also observed. Strains carrying lukS-PV/lukF-PV genes belonged to SCCmecV- spa type t437. The most prevalent spa types were t091, t015, t084, t002, t571, and t026 among all 57 identified. Spa types, including 3 new ones, grouped in 6 different spa-CC clonal complexes, with four major dominated; CC45, CC30, CC5, and CC15. This study demonstrated that both methicillin-susceptible and methicillin-resistant major European clones of S. aureus could be isolated from the oral cavity of dental patients, with the emergence of PVL-positive CA-MRSA strains. The oral cavity should be considered as a possible source of toxigenic egc-positive S. aureus strains, in terms of potential risk of cross-infection and dissemination to other body sites.

Assessment of methicillin resistance and toxin associated genes in staphylococcus species isolated from two selected pig farms in ogun state

Swine especially pigs have been reported to harbor methicillin-resistant Staphylococcus species and have become a source of a novel and rapidly emerging infection in humans. This study was therefore, designed to investigate methicillin resistance status, susceptibility and exfoliative toxin-encoded genes in Staphylococcus species isolated from pigs. Hundred and fifty (150) samples consisting of 50 anal, nostril and environmental swabs were collected at Ode Remo and Sapade in Ogun state after obtaining ethical clearance. These were transferred into transport medium and transported to Microbiology laboratory of Babcock University. The isolates were identified to species level by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry. The phenotypic detection of methicillin resistance and susceptibility of the isolates to selected antibiotic classes were evaluated by agar diffusion and interpreted according to CLSI, 20011. Exfoliative toxin-encoding genes (eta andetb) in the isolates were screened by Polymerase Chain Reaction (PCR). The data were analyzed by descriptive statistics (frequency). Fifty (50) staphylococcal strains were isolated from anus (28), nostril (17) and environment (5) of which Staphylococcus sciuri(23), Staphylococcus cohnii(11), Staphylococcus piscifermentas(7), Staphylococcus carnosus(1), Staphylococcus condiment (3), Staphylococcus xylosus(2), Staphylococcus Kloosii(1), Staphylococcus pasteuri(1) and Staphylococcus succinus(1). Methicillin resistance was detected in 12 strains S. xylosus (1), S. kloosii (1), S. picifermentas (2) and S. sciuri (8) with phenotypic method while none of the strains were positive by molecular counterpart. Susceptibility to other antibiotics indicated that all the strains were resistant to ceftazidimeS. sciuri(23), S. cohnii(11), S. piscifermentas(7), S. carnosus(1), S. condimenti(3), S. xylosus(2), S. kloosii(1), S. pasteuri(1), and S. succinus(1). All the strains were negative for exfoliative toxin encoding genes after several trails in PCR. Methicillin resistance is absent amoung the strains studied and the resistance patterns observed indicated that the pattern of resistance predominantly found in clinical isolates are also emerging in the animal husbandry.

Staphylococcus aureus and Methicillin Resistant S. aureus in Nepalese Primates: Resistance to Antimicrobials, Virulence, and Genetic Lineages.

Staphylococcus aureus is a ubiquitous pathogen and colonizer in humans and animals. There are few studies on the molecular epidemiology of S. aureus in wild monkeys and apes. S. aureus carriage in rhesus macaques (Macaca mulatta) and Assam macaques (Macaca assamensis) is a species that has not previously been sampled and lives in remote environments with limited human contact. Forty Staphylococcus aureus isolates including 33 methicillin-susceptible S. aureus (MSSA) and seven methicillin-resistant S. aureus (MRSA) were characterized. Thirty-four isolates were from rhesus macaques and six isolates (five MSSA, one MRSA) were from Assam macaques. Isolates were characterized using StaphyType DNA microarrays. Five of the MRSA including one from Assam macaque were CC22 MRSA-IV (PVL+/tst+), which is a strain previously identified in Nepalese rhesus. One MRSA each were CC6 MRSA-IV and CC772 MRSA-V (PVL+). One MSSA each belonged to CC15, CC96, and CC2990. Six MRSA isolates carried the blaZ, while ten known CC isolates (seven MRSA, three MSSA) carried a variety of genes including aacA-aphD, aphA3, erm(C), mph(C), dfrA, msrA, and/or sat genes. The other 30 MSSA isolates belonged to 17 novel clonal complexes, carried no antibiotic resistance genes, lacked Panton–Valentine Leukocidin (PVL), and most examined exotoxin genes. Four clonal complexes carried egc enterotoxin genes, and four harbored edinB, which is an exfoliative toxin homologue.