A Rare Case of Panton-Valentine Leukocidin-Related Cervical Empyema

Staphylococcus aureus is found in the normal skin and mucosa of approximately 30% of healthy populations and is the most common pathogen in human disease associated with bacteria. They are divided into methicillin-sensitive S . aureus (MSSA) and methicillin-resistant S. aureus (MRSA). The S. aureus strains carrying the Panton-Valentine leukocidin genes (SA-PVL) were initially believed to belong to the MRSA group; however, recent reports showed they also belonged to the MSSA group (MSSA-PVL). SA-PVL is common in skin and soft-tissue infections but rare in musculoskeletal infections, especially in spondylodiscitis. We are reporting a case suffering from cervical spondylodiscitis and epidural abscess associated with MSSA carrying the Panton-Valentine leukocidin genes.

Molecular and phylogenetic study of Staphylococcus aureus isolated from human and cattle of Al-Qadisiyah Governorate, Iraq

AIM

This study was designed to detect the prevalence of Staphylococcus aureus, to estimate the frequency of methicillin resistance gene (mecA), femA (specific gene for S. aureus), and lukS gene, and the prevalence of urinary tract infection (UTI) in human and bovine mastitis caused by S. aureus.

MATERIALS AND METHODS

A total of 102 cases of S. aureus were included in this study; 72 specimens were isolated from human with UTIs and 30 specimens were isolated from milk of cattle with acute mastitis. Diagnosis was done by VITEK 2 Compact after subculture and purification. All isolates were examined for the presence of mecA, femA, and lukS (Panton-Valentine leukocidin) using multiplex polymerase chain reaction.

RESULTS

Culture and biochemical evaluation of the samples revealed the presence of S. aureus, among which the genes mecA, femA, and lukS were positively detected in 68 (94.4%), 36 (50%), and 20 (27.7%) of S. aureus isolates from methicillin-resistant humans, respectively. In the same manner, the genes mecA, femA, and lukS were positively detected in 27 (90%), 14 (46.7%), and 11 (36.7%) of S. aureus isolates from methicillin-resistant cattle. Sequencing of partial order of femA gene isolated from human isolate and from cattle with mecA isolated from human revealed high sequence identity with the National Center for Biotechnology Information (NCBI)-Basic Local Alignment Search Tool. S. aureus isolates and the phylogenetic analysis showed that there was a significant genetic similarity (0.5 genetic change) between human and animals isolates, and then, the gene sequences were deposited into NCBI-Genbank accession numbers MG696860.1 for mecA and femA from human, MG696861.1 for mecA and femA from cattle, MK474469.1 for mecA and femA gene from human, and MG696862.1 for mecA and femA gene from cattle.

CONCLUSION

The study represents the first report of genetic relationship between S. aureus from humans and cattle of Iraq. Therefore, it is essential to define the role of animals as an important source of the distribution of pathogen related to public health. The continuous monitoring of methicillin susceptibility pattern of S. aureus isolates that have high standards of infections might prevent methicillin-resistant S. aureus transmission in either direction between human and cattle, the risk of dairy milk on humans, or self-direction between the same species.

[Ecthyma gangrenosum associated with infection involving a methicillin-sensitive, Panton-Valentine-negative strain of Staphylococcus aureus]

BACKGROUND

Ecthyma gangrenosum (EG) is an anatomoclinical syndrome commonly associated with Pseudomonas aeruginosa cutaneous infection. Other microorganisms have also been incriminated on occasion, with other viral, fungal and bacterial agents potentially causing EG. In this report, we present an extremely rare case of an EG caused by methicillin-sensitive Staphylococcus aureus (MSSA) infection. This case, highly characteristic of EG both clinically and histologically, calls into question the physiopathological mechanisms of the disease and provides a reminder that it may be caused by a variety of organisms.

PATIENTS AND METHODS

A 62-year-old woman, followed for HIV seropositivity at the AIDS stage, developed a painful purpuric skin rash evolving towards necrotic nodules characteristic of ecthyma gangrenosum. Skin biopsy confirmed the diagnosis of EG due to methicillin-sensitive S. aureus (MSSA) infection without toxins or bacteraemia.

DISCUSSION

To the best of our knowledge, this is the first case in the literature in which MSSA is reported as the underlying cause of such lesions.