Molecular epidemiology of methicillin‐resistant Staphylococcus aureus in the Brazilian primary health care system

et al. 2020

Preprint

Background: People with diabetes mellitus, especially insulin-dependent diabetic patients, are a risk group for staphylococcal infections. Asymptomatic infection with Staphylococcus aureus is common and favors dissemination of the microorganism, rendering these individuals a source of infection. This study aimed to characterize the resistance profile, clonal profile and sequence type, as well as to analyze the prevalence and risk factors for nasal and oropharyngeal carriage of methicillin-susceptible (MSSA) and methicillin-resistant S. aureus (MRSA) isolated from insulin-dependent diabetic individuals in the city of Botucatu, SP, Brazil. Methods: Staphylococcus aureus was collected from the nasopharynx and oropharynx of 312 community-dwelling insulin-dependent diabetic individuals over a period of 3 years (October 2015 to December 2018). The isolates were characterized by susceptibility profiling, detection of the mecA gene, SCCmec typing, and molecular typing by PFGE and MLST. The risk factors associated with S. aureus and MRSA carriage were determined by logistic regression analysis. Results: The overall prevalence of colonization with S. aureus and MRSA was 30.4% and 4.8%, respectively. Fifteen of the 112 S. aureus isolates carried the mecA gene; SCCmec type IV was identified in 10 isolates, SCCmec type I in three, and SCCmec type II in two. Among the 15 resistant isolates (MRSA), four were susceptible to oxacillin/cefoxitin by the disc diffusion method and one MSSA isolate was resistant to sulfamethoxazole/trimethoprim. The analysis of risk factors revealed a protective effect of age and lung disease, while lower-extremity ulcers were a risk factor for S. aureus. For MRSA, only male gender was significantly associated as a risk factor in multivariate analysis. Clonal profile analysis demonstrated the formation of clusters among MRSA isolates from different patients, with the identification of ST5-IV, ST5-I, and ST8-IV. Isolates carrying ST398 were identified among MSSA and MRSA (ST398-IV). Conclusion: Our findings reinforce the importance of epidemiological studies of S. aureus carriage, especially in populations at high risk of infections such as diabetics. The data suggest widespread dissemination of MRSA in the population of insulin-dependent diabetic patients studied, as well as the emergence of important lineages among these individuals.

Section: Discussionsupporting

confidence: 83%

Section: Discussionmentioning

confidence: 99%

Molecular characterization of methicillin-resistant Staphylococcus aureus among insulin-dependent diabetic individuals in Brazil

Teixeira

Fortaleza

et al. 2020

Preprint

“…This fact reinforces the importance of throat colonization, which could be a route of transmission within the population studied. Other studies involving individuals from the same city and region also found MRSA ST5-SCCmec type IV and ST8-SCCmec type IV, suggesting that these strains are prevalent in the region [28,[38][39][40][41][42][43].…”

Section: Discussionmentioning

confidence: 99%

Prevalence and Risk Factors for Nasal and Oropharyngeal Carriage of Staphylococcus Aureus in Insulin-Dependent Diabetics Individuals

Teixeira

Fortaleza

et al. 2020

Preprint

Individuals with insulin-dependent diabetes are a risk group for infections caused by Staphylococcus aureus. The objective of this study was to determine the prevalence and risk factors for nasal and oropharyngeal carriage of S. aureus and MRSA in insulin-dependent diabetic individuals from Botucatu, São Paulo, Brazil. Additionally, susceptibility profiling, detection of the mecA gene, SCCmec typing and molecular typing by PFGE and MLST were performed in nasal and oropharyngeal swabs of 312 subjects. The prevalence of S. aureus and MRSA was 30.4% and 4.8%, respectively. SCCmec type IV was the predominant type among isolates, although some carried SCCmec types I and II. MRSA and MSSA clones were detected among the isolates of this population. In addition, an important clonal lineage (ST398) was identified among resistant and susceptible isolates. Age and lung disease were negatively associated with S. aureus carriage, while lower-extremity ulcers were a risk factor for S. aureus carriage. For MRSA, only male gender was a risk factor. These data suggest widespread dissemination of MRSA in the insulin-dependent diabetic population studied, as well as the emergence of important lineages among these individuals.

“…Reviewing the history of MRSA in Brazil will help to better understand the spread of this important pathogen in Latin America, as well as in the new world. In Brazil, there are some epidemiological surveillance systems of resistant bacteria which do not work at a national level [ 13 , 14 ]. However, in 2018, a program named PAN-BR (National Action Plan for the Prevention and Control of Antimicrobial Resistance in Brazil) was developed [ 15 ].…”

Section: Introductionmentioning

confidence: 99%

“…In the 2010s, MRSA remained being increasingly reported in Brazil, as shown in Figure 4 . The most common clones in the hospital environment continued to be those carrying the SCC mec types II, III, and IV [ 14 , 65 , 73 , 102 , 103 ]. However, SCC mec type II, in contrast to the last decade, was reported as one of the most prevalent clone [ 103 – 109 ].…”

Section: Introductionmentioning

confidence: 99%

The History of Methicillin-Resistant Staphylococcus aureus in Brazil

Andrade

Luiz

Canadian Journal of Infectious Diseases and Medical Microbiolog

et al. 2020

Since the emergence of MRSA in the 1960s, a gradual increase in infections by resistant bacteria has been observed. Clinical manifestations may vary from brand to critical condition due to host risk factors, as well as pathogen virulence and resistance. The high adaptability and pathogenic profile of MRSA clones contributed to its spread in hospital and community settings. In Brazil, the first MRSA isolates were reported in the late 1980s, and since then different genetic profiles, such as the Brazilian epidemic clone (BEC) and other clones considered a pandemic, became endemic in the Brazilian population. Additionally, Brazil’s MRSA clones were shown to be able to transfer genes involved in multidrug resistance and enhanced pathogenic properties. These events contributed to the rise of highly resistant and pathogenic MRSA. In this review, we present the main events which compose the history of MRSA in Brazil, including numbers and locations of isolation, as well as types of staphylococcal cassette chromosome mec (SCCmec) found in the Brazilian territory.