Análisis MLVA y perfil de virulencia de aislamientos de Staphylococcus aureus resistentes a la meticilina adquiridos en la comunidad causantes de infecciones pediátricas en Paraguay

Abstract

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is one of the first causes of skin and soft tissue infections, and can also produce severe diseases such as osteomyelitis and pneumonia. The aim of this descriptive study was to determine the SCCmec type and virulence profile and to study the genetic diversity by MLVA analysis of 21 CA-MRSA isolates that infected Paraguayan children in 2010. The SCCmec type and virulence factors were performed by PCR and genetic diversity by MLVA (multiple locus variable analysis). All the isolates carried SCCmec cassette iv. hla, hlb and sea genes were detected in 28,6%, 9,5% and 4,8% respectively. The MLVA analysis showed high genetic diversity with congruent antibiotic resistance and virulence profiles. This study revealed the presence of CA-MRSA harbouring SCCmeciv with high genetic diversity, providing information not available in our country.

Enterotoxins of EGC Cluster Prevalence in Staphylococcus aureus Collected from Clinical Samples of Paraguayan Children

“…The levels of penicillin resistance observed at the general level, whether the isolates were MRSA or MSSA, coincide with other regional and national studies that report levels of penicillin resistance in community S. aureus isolates greater than 90% in Latin America 21,[25][26][27] . Regarding the levels of resistance to clindamycin and erythromycin reported in this study (24% and 23%, respectively), a significant increase is seen, compared to reports made by our research group in previous studies in bacterial populations collected under the same conditions and geographical regions, but in different temporalities: in 2016, Guillén et al reported clindamycin and erythromycin resistance levels of 6.9% for both antibiotics and in 2020, Rodriguez et al reported clindamycin and erythromycin resistance levels of 15% and 17% respectively 25,27 .…”

“…Other studies conducted by our research group, focused on the detection of coding genes of SEs A, B, C, D, and H, frequently associated with foodborne diseases, yielded carriage percentages for these genes lower than 5% 20,21 in samples collected from SSTI in the pediatric population, which reinforces the theory that these SE are strongly related to the production of gastrointestinal infections and those of the EGC cluster are present in all types of clinical samples and even in asymptomatic carriers 22 .…”

“…In this context, the genomic analysis of a dozen S. aureus isolates belonging to the largest biobank of its kind in Paraguay 14 , allowed our research group to identify in the genome of these isolates genes encoding virulence and antibiotic resistance factors never studied before in our country, such as those of the enterotoxins belonging to the EGC cluster (seg, sei, sem, sen, seo and seu). This important qualitative leap opened up a range of new possibilities for new research projects and assays to be developed to further deepen and deepen the existing knowledge on the epidemiology of circulating S. aureus in Paraguay 1,15 .…”

“…Almost 3/4 of the cases were recorded during the spring-summer months, from September to March in the southern hemisphere, 85% of which corresponded to infectious conditions originating from SSTI. The climatic conditions at this time of the year, characterized by average temperatures above 30°C and relative humidity between 60%-80%, is a favorable combination for the occurrence of skin infections associated with S. aureus 21,27 . Although in the autumn-winter months, the number of isolates collected decreased, the trend of higher frequency of isolates causing skin and soft tissue infections was maintained, probably because in Paraguay the winter is very mild, with average temperatures between 16-19°C due to its subtropical climate.…”