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

Antimicrobial Resistance and Virulence Gene Profile of Clinical Staphylococcus aureus: A Multi-Center Study from Ethiopia

Background

Staphylococcus aureus causes a wide range of infections from mild skin and soft tissue to severe life-threatening bacteremia. The pathogenicity of S. aureus infections is related to various bacterial surface components and extracellular proteins such as toxic-shock syndrome (TSS) toxin and Panton-Valentine leukocidin (PVL). In this study we determine the antimicrobial resistance of isolated strains and their virulence genes in Ethiopia.

Methods

A total of 190 archived S. aureus isolates from four Ethiopia Antimicrobial Resistance (AMR) Surveillance sites were analyzed. The identification of S. aureus was done by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF Biotyper) and antimicrobial susceptibility test (AST) was done using VITEK^® 2. Multiplex PCR was used to detect mecA, mecC, pvl and spa genes and super-antigens (sea, seb, sec, seh and sej staphylococcal enterotoxins).

Results

A total of 172 isolates were confirmed as S. aureus, 9 (5.23%) were methicillin-resistant S. aureus (MRSA) and 163 (94.76%) were methicillin-susceptible S. aureus (MSSA). AST showed that 152 (88.4%) isolates were resistant to penicillin; 90 (52.32%) resistant to trimethoprim-sulfamethoxazole; and 45 (26.16%) resistant to tetracycline. A total of 66 (38.37%) isolates harbored at least one staphylococcal enterotoxin gene and 31 (46.96%) isolates had more than one. The most frequent enterotoxin gene encountered was seb 28 (16.28%). The TSST-1 gene was detected in 23 (13.37%). Presence of staphylococcal enterotoxin gene showed significant association with antibiotic resistance to cefoxitin, benzylpenicillin, oxacillin, erythromycin, clindamycin, tetracycline and SXT. The pvl gene was detected in 102 (59.3%) of isolates. Isolates from patients below 15 years of age showed significantly high numbers of pvl gene (P = 0.02). Presence of sej (P = 0.011) and TSST-1 (P <0.001) genes were associated with the presence of pvl gene.

Conclusion

In this study, isolates were highly resistant to oral antibiotics and the pvl, seb, sea and TSST-1 genes were prevalent.

Acute Prosthetic Joint Infections with Poor Outcome Caused by Staphylococcus Aureus Strains Producing the Panton-Valentine Leukocidin

The aim of this study was to investigate whether the presence of Staphylococcus aureus (SA) producing the Panton-Valentine leukocidin (PVL) affects the outcome of Prosthetic Joint Infection (PJI). Patients with acute and chronic PJI sustained by SA were prospectively enrolled at the orthopedic unit of "Casa di Cura Santa Maria Maddalena", from January 2019 to October 2021. PJI diagnosis was reached according to the diagnostic criteria of the International Consensus Meeting on PJI of Philadelphia. Synovial fluid obtained via joint aspirations was collected in order to isolate SA. The detection of PVL was performed via real-time quantitative PCR (RT-qPCR). The outcome assessment was performed using the criteria of the Delphi-based International Multidisciplinary Consensus. Twelve cases of PJI caused by SA were included. Nine (75%) cases were acute PJI treated using debridement, antibiotic and implant retention (DAIR); the remaining three (25%) were chronic PJI treated using two-stage (n = 2) and one-stage revision (n = 1), respectively. The SA strains that tested positive for PVL genes were 5/12 (41.6%,). Treatment failure was documented in three cases of acute PJI treated using DAIR, all supported by SA-PVL strains (p < 0.045). The remaining two cases were chronic PJI treated with a revision arthroplasty (one and two stage, respectively), with a 100% eradication rate in a medium follow-up of 24 months. Although a small case series, our study showed a 100% failure rate in acute PJI, probably caused by SA PVL-producing strains treated conservatively (p < 0.04). In this setting, toxin research should guide radical surgical treatment and targeted antibiotic therapy.

Surveillance of osteoarticular infections caused by Staphylococcus aureus in a paediatric hospital in Mexico City

Staphylococcus aureus is the main aetiologic agent of osteoarticular infections (OAIs) in paediatric patients. The aim of this prospective unicenter study was to describe the phenotypic and genotypic characteristics of S. aureus isolates obtained from OAIs in paediatric patients admitted to tertiary care hospital. Through a surveillance program called OsteoCode, a multidisciplinary team was created and we identified 27 patients with OAIs caused by S. aureus from 2019 to 2021. The susceptibility profile, virulence factors, biofilm formation, pulsed-field gel electrophoresis (PFGE), clonal complex (CC) and sequence type (ST) were determined. In addition, the clinical characteristics and evolution of the patients presented six months after the diagnosis of OAIs were described. Ninety-two percent of the isolates were methicillin-sensitive S. aureus (MSSA). In methicillin-resistant S. aureus (MRSA), SCCmec-II and SCCmec-V were detected. The pvl gene was only observed in MSSA (18.5%) and was associated with highest fever (p=0.015), multiple localization (p=0.017), and soft tissue sites of infection beyond the bone (pyomyositis, pulmonary abscess) (p=0.017). Biofilm formation was detected in 55.6% of isolates. The most common CC were CC5 and CC30 which represent the most common linages for bone and joint infections worldwide. The isolates were distributed in different STs, and ST672 was predominant. MRSA were associated with a longer duration of intravenous treatment and a prolonged hospital stay (p=0.023). Recurrent infection occurred in five children and orthopaedic complications in 33.3% of patients. This is the first study that reflects the epidemiology of S. aureus in OAIs in paediatric patients in Mexico; a clear predominance of MSSA distributed in different STs was observed. Our findings highlight that a multidisciplinary team is required for the diagnosis and treatment of OAIs.

Paediatric osteoarticular infections caused by staphylococcus aureus producing panton-valentine leucocidin in morocco: Risk factors and clinical features

OBJECTIVE

We aimed to estimate the prevalence of Staphylococcus aureus producing Panton-Valentine leucocidin (PVL) isolated from children diagnosed with osteoarticular infections (OAIs), and to examine risk factors and clinical features.

METHODS

This prospective study was conducted from January 2017 to December 2018. All hospitalised children diagnosed with S. aureus OAI are included. Blood cultures, articular fluids, synovial tissues and/or bone fragments were collected for bacteriological culture. Antimicrobial susceptibility tests were determined by disk diffusion method. Genes encoding methicillin resistance (mecA) and PVL virulence factors (luk-S-PV and luk-F-PV) were detected by multiplex polymerase chain reaction. The demographic, clinical, laboratory, radiographic and clinical features were reviewed prospectively from medical records.

RESULTS

A total of 37 children with S. aureus OAIs were included, 46% of them have PVL-positive infection and 70.6% were male. The mean age was 8.12 years (±4.57), and almost were from rural settings (76.5%). Children with Staphylococcus aureus producing Panton-Valentine leucocidin (SA-PVL) were significantly associated with type of infection (P = 0.005), location of infection (P = 0.037) and abnormal X-ray (P = 0.029). All strains SA-PVL+ are sensitive to methicillin, but one strain SA-PVL negative was methicillin-resistant S. aureus, confirmed by gene mecA positive.

CONCLUSION

The prevalence of S. aureus infections producing PVL toxin was high in OAIs amongst Moroccan children, mainly due to methicillin-susceptible S. aureus. Type and location of infections and abnormal X-ray were significantly associated with SA-PVL. Routine diagnostic testing of PVL-SA, continuous epidemiological surveillance and multidisciplinary management of OAI is essential to prevent serious complications.

Panton-valentine leukocidin Staphylococcus aureus severe infection in an infant: a case report and a review of the literature

Background

Panton-Valentine leukocidin (PVL) is one of the major virulence factor of Staphylococcus aureus (SA) that might be associated with invasive life-threating infections. A prompt diagnosis and adequate treatment are essential in achieving the best outcome and avoiding serious sequelae. We describe a case of severe invasive PVL-SA infection in an infant. A literature review starting from 2010 was also performed in order to discuss clinical presentations, radiological findings, treatment and outcome.

Case presentation

This is a case of a 6-month-old boy who rapidly developed high fever and poor general condition. He was diagnosed as having multiple muscular abscesses, multiple foci of osteomyelitis and bloodstream infections caused by Panton-Valentine leukocidin Methicillin-resistant Staphylococcus aureus. He received intravenous antibiotics and surgical drainage of the abscess with progressive recovery.

Conclusion

Our report highlights the importance of improving awareness of this severe infection, as a prompt diagnosis and adequate manage is essential in order to save life and to prevent serious complications.

Acute osteoarticular infections in children are frequently forgotten multidiscipline emergencies: beyond the technical skills

Acute osteoarticular infections (AOI) should be treated as top emergencies. The first few days following the inception of infection are ultra-critical to long-term prognosis.A comprehensive road map for management of childhood AOI is still lacking despite recent advances in microbiology and imaging (magnetic resonance imaging). The many faces of childhood AOI warrant a multidiscipline approach to management.Laboratory and imaging findings of are still debatable and should not overshadow or delay a management plan based on the experienced physician's clinical judgment.Ample evidence-based practice supports the use of a few days of intravenous antibiotic administration followed by oral therapy until correlative clinical and basic laboratory (acute phase reactants) results improve.The growing body of evidence on 'high-risk' children/neonates of AOI warrants continual clinical extra-vigilance in identifying these patient subsets.Open drainage and debridement remain the mainstay of treatment of septic hips, whereas for other joints the use of alternative surgical techniques should be individualized or on case-by-case basis.Because the consequences of misdiagnosis of AOI are usually grave and permanent, proactive treatment/overtreatment is justified in the event of unconfirmed but suspicious diagnosis. Cite this article: EFORT Open Rev 2021;6:584-592. DOI: 10.1302/2058-5241.6.200155.

Acute infectious osteomyelitis in children: new treatment strategies for an old enemy

BACKGROUND

Acute osteomyelitis still represents a significant clinical challenge, with an increasing incidence in paediatric population. A careful assessment and a rapid diagnosis with proper timing and choice of empirical antimicrobial therapy are necessary to avoid sequelae. The initial treatment should consist of empirical antibiotic therapy, to cover the major responsible pathogens in each age group.

DATA SOURCES

We made a literature search with PubMed and Cochrane database from 2000 to 2019 in English, French, and Spanish languages using the key words "osteomyelitis, children, clinical, diagnosis, and treatment".

RESULTS

The child's clinical features, age, and the microbiological profile of the geographic area should be evaluated for diagnosis and in the choice of antibiotic treatment. Latest data suggest the administration of intravenous antibiotics for a short period, with subsequent oral therapy, according to the improvement of clinical status and inflammatory markers. For children older than 3 months, the shift to oral medications is already possible after a short course of intravenous therapy, until recovery. The timing for the shift from cefazolin to cephalexin or cefuroxime, intravenous clindamycin to oral clindamycin, and intravenous ceftriaxone + oxacillin to oral equivalents will be decided according to the improvement of clinical status and inflammatory markers. We also present the approach to osteomyelitis due to difficult pathogens, such as Methicillin-resistant Staphylococcus aureus (MRSA) and Panton-Valentine leukocidin (PVL)-positive S. aureus infections.

CONCLUSION

In this review, we present the current approach to the clinical diagnosis and management of osteomyelitis in childhood, with an update on recent recommendations, as a useful instrument to understand the rationale of antibiotic therapy.