Bone and joint infections with Staphylococcus aureus strains producing Panton-Valentine Leukocidin in French Guiana.

The aim of this study was to describe the clinical features of bone and joint infections (BJI) due to Panton-Valentine Leukocidin producing (PVL+) Staphylococcus aureus (SA) in French Guiana.A multicenter study that consists of a retrospective charts review of children admitted for PVL+ S. aureus BJI between January 2010 and December 2015.Six patients with SA-PVL BJI were identified during the study period: 2 osteomyelitis, 1 septic arthritis, and 3 disseminated BJI. The median age was 11 years old (4-14 years), and fever lasted for 3.2 days (2-5 days) before diagnosis. An open skin wound preceded the BJI in 5/6 patients. One patient presented with a septic thrombophlebitis of the femoral-popliteal vein on admission. Methicillin-susceptible Staphylococcus aureus (MSSA) were identified for all patients. Three patients had complications: 2 cases of necrotizing pneumonia and 2 pericarditis, with 1 death caused by cardiac tamponade.SA-PVL BJI was not frequent. Strains were susceptible to methicillin, but responsible of severe BJI. Early diagnosis and a multidisciplinary management of these infections are essential to prevent further complications.

A fast and simple assay to quantify bacterial leukotoxin activity

Background: Mannheimia haemolytica is the primary bacterial pathogen in causing bovine respiratory disease with tremendous annual losses in the cattle industry. The leukotoxin from M. haemolytica is the predominant virulence factor. Several leukotoxin activity assays are available but not standardized regarding sample preparation and cell line. Furthermore, these assays suffer from a high standard error, a prolonged time consumption and often complex sample pretreatments, which is important from the bioprocess engineering point of view. Results: Within this study, an activity assay based on the continuous cell line BL3.1 combined with a commercial available adenosine triphosphate viability assay kit was established. The leukotoxin activity was found to be strongly dependent on the sample preparation. Furthermore, the interfering effect of lipopolysaccharides in the sample could be successfully suppressed by adding polymyxin B. We reached a maximum relative P95 value of 14%, which is more than seven times lower compared to current available assays as well as a time reduction up to 88%. Conclusion: Ultimately, the established leukotoxin activity assay is simple, fast and has a high reproducibility. Critical parameters regarding the sample preparation were characterized and optimized making complex sample purification superfluous.

Disseminated Panton-Valentine Leukocidin-Positive Staphylococcus aureus infection in a child.

Panton-Valentine leukocidin (PVL) is an exotoxin that is produced by many strains of Staphylococcus aureus, and an important virulence factor. A PVL-positive S. aureus infection leads to rapid and severe infections of soft tissue and necrotizing pneumonia in healthy adolescents, and has a high mortality. This case report included a 12-year-old male patient who admitted for fever, respiratory distress and hip pain and was identified with necrotizing pneumonia with septic pulmonary embolism, psoas abscess, cellulitis and osteomyelitis. The PVL positive methicillin-sensitive S. aureus (MSSA) was isolated in the patient blood culture.

La leucocidina de Panton-Valentine (LPV) es una exotoxina producida por muchas cepas de Staphylococcus aureus, y un importante factor de virulencia. Una infección por S. aureus positivo para LPV deriva en infecciones rápidas y graves de partes blandas y neumonía necrosante en adolescentes sanos, y la tasa de mortalidad es elevada. Presentamos el caso de un paciente de 12 años hospitalizado por fiebre, dificultad respiratoria y coxalgia en el que se identificó neumonía necrosante con embolia pulmonar séptic absceso del psoas, celulitis y osteomielitis. En el hemocultivo del paciente se aisló S. aureus sensible a la meticilina (SASM) positivo para LPV.

Infección diseminada por Staphylococcus aureus positivo para leucocidina de Panton-Valentine en un niño / Disseminated Panton-Valentine Leukocidin-Positive Staphylococcus aureus infection in a child

La leucocidina de Panton-Valentine (LPV) es una exotoxina producida por muchas cepas de Staphylococcus aureus, y un importante factor de virulencia. Una infección por S. aureus positivo para LPV deriva en infecciones rápidas y graves de partes blandas y neumonía necrosante en adolescentes sanos, y la tasa de mortalidad es elevada. Presentamos el caso de un paciente de 12 años hospitalizado por fiebre, dificultad respiratoria y coxalgia en el que se identificó neumonía necrosante con embolia pulmonar séptica, absceso del psoas, celulitis y osteomielitis. En el hemocultivo del paciente se aisló S. aureus sensible a la meticilina (SASM) positivo para LPV.

Panton-Valentine leukocidin (PVL) is an exotoxin that is produced by many strains of Staphylococcus aureus, and an important virulence factor. A PVL-positive S. aureus infection leads to rapid and severe infections of soft tissue and necrotizing pneumonia in healthy adolescents, and has a high mortality. This case report included a 12-year-old male patient who admitted for fever, respiratory distress and hip pain and was identified with necrotizing pneumonia with septic pulmonary embolism, psoas abscess, cellulitis and osteomyelitis. The PVL positive methicillin-sensitive S. aureus (MSSA) was isolated in the patient blood culture.

Major West Indies MRSA clones in human beings: do they travel with their hosts?

BACKGROUND: Descriptions of the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) have seldom been produced in the Caribbean, which is a major tourism destination. MATERIALS AND METHODS: Using DNA microarrays and spa typing, we characterized 85 MRSA isolates from human skin and soft-tissue infections from five different islands. RESULTS: In the French West Indies (n = 72), the most frequently isolated clones were the same clones that are specifically isolated from mainland France [Lyon (n = 35) and Geraldine (n = 11) clones], whereas the clones that were most frequently isolated from the other islands (n = 13) corresponded with clones that have a worldwide endemic spread [Vienna/Hungarian/Brazilian (n = 5), Panton Valentine leukocidin-positive USA300 (n = 4), New York/Japan (n = 2), and pediatric (n = 1) clones]. CONCLUSION: The distribution of the major MRSA clones in the French (Guadeloupe and Martinique) and non-French West Indies (Jamaica, Trinidad, and Tobago) is different, and the clones most closely resemble those found in the home countries of the travelers who visit the islands most frequently. The distribution might be affected by tourist migration, which is specific to each island.

Nasal carriage of Panton Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus in healthy preschool children / Colonización nasal de Staphylococcus aureus Meticilino Resistente portador de la Leucocidina Panton-Valentine en preescolares

Objective Determining the prevalence of nasal carriage of S. aureus, both sensitive to methicillin and resistant to it, in preschool children and evaluating the presence of Panton-Valentine leukocidin genes in the isolates. Methods This was a cross-sectional study in which cultures from anterior nares were obtained from healthy preschool children. Isolates were identified as S. aureus based on morphological and biochemical tests. Antibiotic susceptibility profiles were determined by the disk diffusion method. All the isolates were further analyzed by multiplex PCR to determine the presence of mecA and PVL genes; methicillin-resistant isolates were also SCCmec typed by multiplex PCR. Results Overall S. aureus nasal colonization prevalence was 38.5 % and 4.8 % for methicillin-resistant strains. All the methicillin-resistant isolates carried the genes for PVL; two isolates possessed the SCCmec type IV, two were SCCmec type I and one was SCCmec type II. Conclusion This study revealed high PVL-positive, methicillin-resistant S. aureus colonization prevalence in healthy preschool children from Cartagena, which may play a key role in the epidemiology of community-associated infection by methicillin-resistant S. aureus in healthy children from this particular geographical area.

Objetivo Determinar la prevalencia de colonización nasal de S. aureus, tanto sensible como resistente a meticilina, en niños preescolares y evaluar la presencia de los genes de la leucocidina Panton-Valentine en estos aislamientos. Métodos Estudio de corte transversal en el que se realizaron cultivos de flora nasal de niños preescolares. Los aislamientos fueron identificados como S. aureus con base en su morfología y pruebas bioquímicas. La susceptibilidad a antibióticos se determinó por el método de difusión en disco. Todos los aislamientos fueron analizados por PCR múltiple para determinar la presencia de los genes mecA y PVL, y para la tipificación del casete cromosómico SCCmec de los aislamientos resistentes a meticilina. Resultados La colonización nasal por S. aureus fue 38,5 %, y la de cepas meticilino-resistentes fue 4,8 %. Todos los aislamientos SARM portaban los genes para PVL, dos portaban el elemento SCCmec tipo IV, dos fueron tipo I y uno fue tipo II. Conclusión Encontramos una alta prevalencia de colonización por cepas meticilino-resistentes, PVL-positivos en la población estudiada, lo que podría jugar un papel clave en la epidemiología de las infecciones por S.aureus meticilino-resistente en esta área geográfica.

Nasal carriage of Panton Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus in healthy preschool children.

OBJECTIVE: Determining the prevalence of nasal carriage of S. aureus, both sensitive to methicillin and resistant to it, in preschool children and evaluating the presence of Panton-Valentine leukocidin genes in the isolates. METHODS: This was a cross-sectional study in which cultures from anterior nares were obtained from healthy preschool children. Isolates were identified as S. aureus based on morphological and biochemical tests. Antibiotic susceptibility profiles were determined by the disk diffusion method. All the isolates were further analyzed by multiplex PCR to determine the presence of mecA and PVL genes; methicillin-resistant isolates were also SCCmec typed by multiplex PCR. RESULTS: Overall S. aureus nasal colonization prevalence was 38.5 % and 4.8 % for methicillin-resistant strains. All the methicillin-resistant isolates carried the genes for PVL; two isolates possessed the SCCmec type IV, two were SCCmec type I and one was SCCmec type II. CONCLUSION: This study revealed high PVL-positive, methicillin-resistant S. aureus colonization prevalence in healthy preschool children from Cartagena, which may play a key role in the epidemiology of community-associated infection by methicillin-resistant S. aureus in healthy children from this particular geographical area.

Occurrence of Aggregatibacter actinomycetemcomitans in Brazilian Indians from Umutina Reservation, Mato Grosso, Brazil.

UNLABELLED: Aggregatibacter actinomycetemcomitans is associated with periodontal disease, especially localized aggressive periodontitis, produces a potent leukotoxin and its distribution is influenced by ethnic characteristics of the population. OBJECTIVE: Using culture and polymerase chain reaction (PCR) techniques, this study evaluated the occurrence of this microorganism and the distribution of leukotoxic strains isolated from Indians belonging to the Umutima Reservation, Mato Grosso, Brazil. MATERIAL AND METHODS: Forty-eight native Brazilians with gingivitis and 38 with chronic periodontitis, belonging to Umutina, Paresi, Bororo, Bakairi, Kayabi, Irantxe, Nambikwara and Terena ethnicities, were studied. Subgingival, supragingival and saliva samples of each patient were collected and transferred to VMGA III medium and to ultra pure Milli Q water. Bacteria were grown on TSBV agar and incubated in anaerobiosis (90% N2 + 10% CO2) at 37 degrees C for 72 h. The presence of the ltx promoter was determined by PCR, and a 530 bp deletion in the promoter was evaluated by using specific primers. RESULTS: A. actinomycetemcomitans was isolated from 8.33% of saliva, supragingival and subgingival samples from patients with gingivitis and from 18.42% of saliva and supragingival biofilm, and 26.32% subgingival biofilm from patients with chronic periodontitis. By PCR, the bacterial DNA was detected in 8.33% of saliva, supragingival and subgingival biofilms from patients with gingivitis and from 23.68% of saliva, 28.95% supragingival biofilm and 34.21% subgingival biofilm from patients with periodontitis. All strains were grouped as non-JP2 clones based on the absence of deletion in the leukotoxin promoter. Differences among the microbial and clinical parameters in patients were analyzed by using the Mann-Whitney, Chi-square or Fisher's exact tests. CONCLUSIONS: The present results suggest that A. actinomycetemcomitans can be related to the attachment loss in this population, but the presence of minimally leukotoxic strains, as well as its role in the pathogenesis of the periodontitis in these native Brazilians need to be further investigated.

Occurrence of Aggregatibacter actinomycetemcomitans in Brazilian indians from Umutina Reservation, Mato Grosso, Brazil

Aggregatibacter actinomycetemcomitans is associated with periodontal disease, especially localized aggressive periodontitis, produces a potent leukotoxin and its distribution is influenced by ethnic characteristics of the population. Objective: Using culture and polymerase chain reaction (PCR) techniques, this study evaluated the occurrence of this microorganism and the distribution of leukotoxic strains isolated from Indians belonging to the Umutima Reservation, Mato Grosso, Brazil. MATERIAL AND METHODS: Forty-eight native Brazilians with gingivitis and 38 with chronic periodontitis, belonging to Umutina, Paresi, Bororo, Bakairi, Kayabi, Irantxe, Nambikwara and Terena ethnicities, were studied. Subgingival, supragingival and saliva samples of each patient were collected and transferred to VMGA III medium and to ultra pure Milli Q water. Bacteria were grown on TSBV agar and incubated in anaerobiosis (90 percent N2 + 10 percent CO2) at 37ºC for 72 h. The presence of the ltx promoter was determined by PCR, and a 530 bp deletion in the promoter was evaluated by using specific primers. RESULTS: A. actinomycetemcomitans was isolated from 8.33 percent of saliva, supragingival and subgingival samples from patients with gingivitis and from 18.42 percent of saliva and supragingival biofilm, and 26.32 percent subgingival biofilm from patients with chronic periodontitis. By PCR, the bacterial DNA was detected in 8.33 percent of saliva, supragingival and subgingival biofilms from patients with gingivitis and from 23.68 percent of saliva, 28.95 percent supragingival biofilm and 34.21 percent subgingival biofilm from patients with periodontitis. All strains were grouped as non-JP2 clones based on the absence of deletion in the leukotoxin promoter. Differences among the microbial and clinical parameters in patients were analyzed by using the Mann-Whitney, Chi-square or Fisher's exact tests. CONCLUSIONS: The present results suggest that A. actinomycetemcomitans ...

Prevalence of periodontal pathogens in Brazilians with aggressive or chronic periodontitis.

OBJECTIVES: Previous studies suggest differences between geographically and racially distinct populations in the prevalence of periodontopathic bacteria as well as greater periodontal destruction associated with infection by highly leucotoxic Actinobacillus actinomycetemcomitans. The present study examined these hypotheses in Brazilians with aggressive or chronic periodontitis. MATERIALS AND METHODS: Clinical, radiographical, and microbiological assessments were performed on 25 aggressive periodontitis and 178 chronic periodontitis patients including 71 males and 132 females, 15-69 years of age. RESULTS: The prevalence of Porphyromonas gingivalis was similar to that of other South American populations. The prevalence of A. actinomycetemcomitans and its highly leucotoxic subgroup was higher in Brazilians. Highly leucotoxic A. actinomycetemcomitans was more prevalent in aggressive periodontitis (chi2=27.83) and positively associated with deep pockets (>6 mm, chi2=18.26) and young age (<29 years, chi2=18.68). Greater mean attachment loss was found in subjects with highly leucotoxic A. actinomycetemcomitans than in subjects with minimally leucotoxic (p=0.0029) or subjects not infected (p=0.0001). CONCLUSION: These data support the hypothesis of differences between populations in the prevalence of periodontopathic bacteria and of greater attachment loss in sites infected with highly leucotoxic A. actinomycetemcomitans. Detection of highly leucotoxic A. actinomycetemcomitans in children and adolescents may be a useful marker for aggressive periodontitis.

Fatal group a streptococcal toxic shock-like syndrome in a child with varicella: report of the first well documented case with detection of the genetic sequences that code for exotoxins SPE A and B, in Sao Paulo, Brazil

Crianca de sete anos, previamente higida, foi admitida na unidade de terapia intensiva por quadro de toxemia associado a varicela. Evoluiu rapidamente para choque e insuficiencia de multiplos orgaos e sistemas e, apesar do tratamento intensivo, morreu no quarto dia apos a admissao. A cultura de secrecao colhida por puncao profunda de partes moles em regiao toracica foi positiva para Streptococcus pyogenes, proteina-M nao tipavel e carreador dos genes codificadores da producao de exotoxinas pirogenicas estreptococicas A e B, preenchendo os criterios para definicao de Sindrome do choque toxico estreptococico. Os autores discutem aspectos clinicos e fisiopatologicos desta sindrome, bem como alguns aspectos incomuns relacionados a este caso