Prevalence, risk factors, phenotypic and molecular characteristics for Staphylococcus aureus carriage in community-based drug users in Guangzhou, China

Abstract

Background: Staphylococcus aureus (S. aureus), particularly methicillin-resistant Staphylococcus aureus (MRSA), remains the predominant cause of infections in drug users. This cross-sectional study aims to elucidate the prevalence, risk factors, phenotypic and molecular characteristics of S. aureus carriage among community-based drug users. Methods: All eligible drug users, with both injection and non-injection route of drug administration, were asked to complete questionnaires and collect nasal swabs by trained personal during the period between May and December 2017 in Guangzhou, China. Swabs were processed for identification of S. aureus. Antimicrobial susceptibility test and polymerase chain reaction assays were used to detect phenotypic and molecular characteristics for identified isolates. Univariate and multivariate logistic regression analyses were used to assess risk factors for S. aureus carriage. Results: Overall, 353 drug users were included in the study and the prevalence of S. aureus carriage was 15.01% (53/353). The prevalence of MRSA carriage was 6.80% (24/353). Cohabitation was a risk factor for S. aureus (adjusted OR = 8.80, 95% CI: 1.89-40.99). The proportion of multidrug resistance was 54.72% for S. aureus isolates and most of these isolates were resistant to penicillin, erythromycin and clindamycin. Seventeen MRSA isolates were multidrug resistant. The results of clonal complexes (CCs) and sequence types (STs) for S. aureus were diverse. The three predominant types for CCs were CC5 (64.15%, 34/53), CC59 (11.32%, 6/53), and CC7 (7.55%, 4/53); and for STs were ST188 (20.75%, 11/53), ST5 (11.32%, 6/53), and ST59 (11.32%, 6/53). Conclusion: The prevalence of S. aureus nasal carriage was lower while the prevalence of MRSA carriage was moderate compared to previous studies. Phenotypic and molecular characteristics of S. aureus isolates, particularly MRSA isolates, revealed high proportions of antibiotic resistance, indicating the existence of cross-circulation, and implying high opportunity of virulence-related diseases. Decolonization and antibiotic stewardship might be implemented for drug users with MRSA carriage.

Assessment of Bacterial Infections and Antibiotic Regimens in Intravenous Drug Users

“…This is formidable in view of public health as hospitalizations for infections related to IDU are distinguished by a prolonged stay at the hospital as well as frequent readmission rates, higher patient-directed discharge, and increased intermediate to long-term mortality leading to significant expense to the healthcare system [ 8 ][ 9 ]. Furthermore, the increased need for antibiotics in PWID contributes to the development of multidrug-resistant bacteria and MRSA colonization [ 6 , 11 , 15 ]. Infected PWIDs can eventually introduce drug-resistant strains to the general public or immunocompromised individuals [ 11 ].…”

“…In addition to SSTI, bacteremia, community-acquired pneumonia, infective endocarditis (IE), skeletal infections like osteomyelitis, and subdural and epidural abscesses are a few other common infections seen in PWID [4]. These complications increase the rate of hospitalizations and hospital expenses, the development of severe comorbidities like kidney injury, septic emboli, and stroke, and increase long-term mortality among PWID [4][5][6][7][8][9][10]. This situation is especially grave considering that the escalated need for antibiotics among this group leads to the emergence of multidrug-resistant bacteria and methicillinresistant Staphylococcus aureus (MRSA) colonization [6,11,12].…”

“…These complications increase the rate of hospitalizations and hospital expenses, the development of severe comorbidities like kidney injury, septic emboli, and stroke, and increase long-term mortality among PWID [4][5][6][7][8][9][10]. This situation is especially grave considering that the escalated need for antibiotics among this group leads to the emergence of multidrug-resistant bacteria and methicillinresistant Staphylococcus aureus (MRSA) colonization [6,11,12]. From the point of view of public health, PWID infected with these strains could introduce them to the general public or immunocompromised people [11].…”