Molecular characterization of methicillin-resistant Staphylococcus aureus clinical isolates obtained from the Rikers Island Jail System from 2009 to 2013

Sequence types 8, 59, and 45 methicillin resistant Staphylococcus aureus as the predominant strains causing skin and soft tissue infections in Taiwan's prisons and jails

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is the predominant cause of skin and soft tissue infections (SSTIs), which is a problem in prisons and jails. We conducted this study to understand MRSA molecular characteristics among inmates with SSTIs, and we chose MRSA isolates from a community hospital as a comparison.

METHODS

A total of 219 MRSA isolates from three custodial facilities and 134 isolates from a community hospital in Taiwan were collected in the 2017 calendar year. MRSA isolates were investigated molecularly by staphylococcal chromosome cassette mec (SCCmec) type, mupirocin, and chlorhexidine genotypical resistance, and multi-locus sequence typing (ST).

RESULTS

Of the 219 MRSA isolates from custodial facilities, SCCmec IV was the most prevalent type (65.3%), followed by type V_T (32.4%) and type V (1.8%). Regarding sequence types, ST59 (36.4%), 8 (35.3%), and 45 (17.9%) were the leading three predominant types out of 184 selected MRSA isolates, and ST45 MRSA was more prevalent in custodial facilities (p = 0.019). The antimicrobial resistance rates varied for different MRSA strains, with ST45 MRSA having the lowest rates of resistance to most antimicrobials. Overall, 91.5% of isolates carried mupA gene and 25.8% were positive for qacA/B gene, this was independent of the MRSA sequence types.

CONCLUSIONS

ST59, ST8, and ST45 MRSA are the leading three MRSA strains causing SSTIs in Taiwan, 2017, but the molecular distribution varied distinctly between the custodial facilities and hospital settings. The genotypical mupirocin resistance rate is quite high in this study. The frequency of chlorhexidine resistance gene is relatively low, especially in MRSA isolates from custodial facilities.

Current and Emerging Topical Antibacterials and Antiseptics: Agents, Action, and Resistance Patterns

Bacterial skin infections represent some of the most common infectious diseases globally. Prevention and treatment of skin infections can involve application of a topical antimicrobial, which may be an antibiotic (such as mupirocin or fusidic acid) or an antiseptic (such as chlorhexidine or alcohol). However, there is limited evidence to support the widespread prophylactic or therapeutic use of topical agents. Challenges involved in the use of topical antimicrobials include increasing rates of bacterial resistance, local hypersensitivity reactions (particularly to older agents, such as bacitracin), and concerns about the indiscriminate use of antiseptics potentially coselecting for antibiotic resistance. We review the evidence for the major clinical uses of topical antibiotics and antiseptics. In addition, we review the mechanisms of action of common topical agents and define the clinical and molecular epidemiology of antimicrobial resistance in these agents. Moreover, we review the potential use of newer and emerging agents, such as retapamulin and ebselen, and discuss the role of antiseptic agents in preventing bacterial skin infections. A comprehensive understanding of the clinical efficacy and drivers of resistance to topical agents will inform the optimal use of these agents to preserve their activity in the future.

Drug Use Is Associated With Purulent Skin and Soft Tissue Infections in a Large Urban Jail: 2011-2015

Background

Skin and soft tissue infections (SSTIs) are a common problem in jails in the United States. This study aimed to identify factors associated with purulent SSTIs in the New York City jail system.

Methods

We conducted a case-control study of purulent SSTIs at the New York City jail. Cases were matched to controls by visit date to the jail’s urgent care clinic. Bivariate and multivariable analyses were conducted using conditional logistic regression.

Results

From April 2011 to April 2015, 1010 cases of SSTIs were identified and matched to 1010 controls. In multivariable analyses, report upon entry to jail of current injection drug use (odds ratio [OR], 2.76; 95% confidence interval [CI], 1.77–4.31), current snorting of drugs (OR, 1.50; 95% CI, 1.12–2.00), current heroin use (OR, 1.53; 95% CI, 1.08–2.17), current cocaine use (OR, 1.76; 95% CI, 1.18–2.65), and antibiotic use within the previous 6 months (OR, 4.05; 95% CI, 2.98–5.49) were significantly associated with SSTI diagnosis.

Conclusions

Skin and soft tissue infections were strongly associated with a history of drug use at jail entry. Targeting intravenous drug use may be a preventive strategy for SSTIs in this population. Strategies such as harm reduction programs may be investigated.

HIV and colonization with Staphylococcus aureus in two maximum-security prisons in New York State

OBJECTIVE

To evaluate the association between HIV and Staphylococcus aureus colonization after confounding by incarceration is removed.

METHOD

A cross sectional stratified study of all HIV infected and a random sample of HIV-uninfected inmates from two maximum-security prisons in New York State. Structured interviews were conducted. Anterior nares and oropharyngeal samples were cultured and S. aureus isolates were characterized. Log-binomial regression was used to assess the association between HIV and S. aureus colonization of the anterior nares and/or oropharynx and exclusive oropharynx colonization. Differences in S. aureus strain diversity between HIV-infected and uninfected individuals were assessed using Simpson's Index of Diversity.

RESULTS

Among 117 HIV infected and 351 HIV uninfected individuals assessed, 47% were colonized with S. aureus and 6% were colonized with methicillin resistant S. aureus. The prevalence of S. aureus colonization did not differ by HIV status (PR = 0.99, 95% CI = 0.76-1.24). HIV infected inmates were less likely to be exclusively colonized in the oropharynx (PR = 0.55, 95% CI = 0.30-0.99). Spa types t571 and t064 were both more prevalent among HIV infected individuals, however, strain diversity was similar in HIV infected and uninfected inmates.

CONCLUSIONS

HIV infection was not associated with S. aureus colonization in these maximum-security prison populations, but was associated with decreased likelihood of oropharyngeal colonization. Factors that influence colonization site require further evaluation.