Phylogenetic and Molecular Profile of Staphylococcus aureus Isolated from Bloodstream Infections in Northeast Brazil

Abstract

Staphylococcus aureus is a notorious human pathogen associated with serious nosocomial and community-acquired infections, such as pneumonia, meningitis, endocarditis, toxic shock syndrome, and sepsis, among others. The objective of this study was to investigate the molecular profile, antimicrobial resistance, and clonal diversity of S. aureus isolated from the bloodstream. The determination of the minimum inhibitory concentration (MIC) of the antimicrobial was performed by an automated method. The presence of several virulence and resistance genes was evaluated by PCR. In addition, multilocus sequence typing (MLST) was used to analyze the clonal diversity of S. aureus. A high resistance to oxacillin (78%), clindamycin (78%), erythromycin (70%), ciprofloxacin (61%), and gentamicin (52%) was observed among the isolates. In most of them, the following virulence genes were detected: hlb (83%), ebpS (61%), icaA (57%), fnbpA (17%), and clfA (13%). Only one isolate carried the pvl gene. MLST analysis identified five new sequence types (STs): 5429, 5430, 5431, 5432, and 5433, as well as another seven—ST5, ST97, ST398, ST101, ST30, ST461, and ST2779—among the remaining strains. These seven STs and the four new STs are clustered in four clonal complexes: CC1, CC2, CC7, and CC17. Phylogenetic analysis showed the genetic relationship of the five new ST strains with another 18 strains. Altogether, these analyses indicate the horizontal transfer acquisition of virulence factor genes and multidrug resistance.

Regulation of virulence and β-lactamase gene expression in Staphylococcus aureus isolates: cooperation of two-component systems in bloodstream superbugs

“…Moreover, the remaining six isolates were found to belong to ST30. Other reports described a collection of S. aureus isolates that commonly belong to ST30 and ST22 [ 36 , 37 ]. The NBJ tree of the ST30 gene included six isolates into one central cluster.…”

Bioguided Purification of Active Compounds from Leaves of Anadenanthera colubrina var. cebil (Griseb.) Altschul

“…In particular, S. aureus are prevalent in the hospital environment and associated with many cases of prolonged hospitalizations and deaths [41,42,45]. Several strains of this species have also acquired resistance to multiple drugs and hypervirulent profiles; these characteristics make the treatment options for S. aureus very limited [46,47]. These features make S. aureus is one of the most devastating pathogens and highlight the need to identify new effective compounds [48,49].…”

Ocorrência De Fasciola Hepatica Na Região Da Campanha Gaucha/Rs

“…A síntese de biofilme fornece defesa contra vários mecanismos imunológicos do hospedeiro e da ação dos agentes antimicrobianos. Neste sentido, linhagens com resistência a múltiplas drogas possuem também geralmente elevada capacidade de produzir biofilme, a exemplo das linhagens de MRSA (AZMI; QREI; ABDEEN, 2019;MONTEIRO et al, 2019).…”

“…Diversos genes estão envolvidos na produção e manutenção de biofilmes por S. aureus. Estudos indicam que a formação do biofilme é mediada pelo operon icaADBC, presente na maioria das linhagens de MRSA e MSSA (MONTEIRO et al, 2019;SERRAY et al, 2016). Este locus está envolvido com a produção da adesina intercelular polissacarídica (PIA) presente na matriz extracelular de S. aureus.…”