Nasal carriers of Staphylococcus aureus are at increased risk for health care-associated infections with this organism. Decolonization of nasal and extranasal sites on hospital admission may reduce ...this risk.
In a randomized, double-blind, placebo-controlled, multicenter trial, we assessed whether rapid identification of S. aureus nasal carriers by means of a real-time polymerase-chain-reaction (PCR) assay, followed by treatment with mupirocin nasal ointment and chlorhexidine soap, reduces the risk of hospital-associated S. aureus infection.
From October 2005 through June 2007, a total of 6771 patients were screened on admission. A total of 1270 nasal swabs from 1251 patients were positive for S. aureus. We enrolled 917 of these patients in the intention-to-treat analysis, of whom 808 (88.1%) underwent a surgical procedure. All the S. aureus strains identified on PCR assay were susceptible to methicillin and mupirocin. The rate of S. aureus infection was 3.4% (17 of 504 patients) in the mupirocin-chlorhexidine group, as compared with 7.7% (32 of 413 patients) in the placebo group (relative risk of infection, 0.42; 95% confidence interval CI, 0.23 to 0.75). The effect of mupirocin-chlorhexidine treatment was most pronounced for deep surgical-site infections (relative risk, 0.21; 95% CI, 0.07 to 0.62). There was no significant difference in all-cause in-hospital mortality between the two groups. The time to the onset of nosocomial infection was shorter in the placebo group than in the mupirocin-chlorhexidine group (P=0.005).
The number of surgical-site S. aureus infections acquired in the hospital can be reduced by rapid screening and decolonizing of nasal carriers of S. aureus on admission. (Current Controlled Trials number, ISRCTN56186788.)
Streptococcus suis: An Emerging Human Pathogen Hughes, James M.; Wilson, Mary E.; Wertheim, Heiman F. L. ...
Clinical infectious diseases,
03/2009, Volume:
48, Issue:
5
Journal Article
Peer reviewed
Streptococcus suis infection is acquired through exposure to contaminated pigs or pig meat. Over the past few years, the number of reported S. suis infections in humans has increased significantly, ...with most cases originating in Southeast Asia, where there is a high density of pigs. Increased awareness, improved diagnostics, and the occurrence of outbreaks have contributed to this increase. Meningitis and sepsis are the most common clinical manifestations of S. suis infection; hearing loss is a frequent complication. In this article, we provide an overview of the emergence and clinical manifestations of S. suis infection.
Summary Staphylococcus aureus bacteraemia is one of the most common serious bacterial infections worldwide. In the UK alone, around 12 500 cases each year are reported, with an associated mortality ...of about 30%, yet the evidence guiding optimum management is poor. To date, fewer than 1500 patients with S aureus bacteraemia have been recruited to 16 controlled trials of antimicrobial therapy. Consequently, clinical practice is driven by the results of observational studies and anecdote. Here, we propose and review ten unanswered clinical questions commonly posed by those managing S aureus bacteraemia. Our findings define the major areas of uncertainty in the management of S aureus bacteraemia and highlight just two key principles. First, all infective foci must be identified and removed as soon as possible. Second, long-term antimicrobial therapy is required for those with persistent bacteraemia or a deep, irremovable focus. Beyond this, the best drugs, dose, mode of delivery, and duration of therapy are uncertain, a situation compounded by emerging S aureus strains that are resistant to old and new antibiotics. We discuss the consequences on clinical practice, and how these findings define the agenda for future clinical research.
Vietnam is an important producer of aquaculture products, and aquatic products are essential to the Vietnamese diet. However, Vietnam also has very little enforced regulation pertaining to antibiotic ...usage in domestic aquaculture, which raises concerns for antibiotic resistance in pathogenic bacteria. In this study, analysis was conducted on the presence of antibiotic residues in domestically sold fish and shrimp raised in freshwater farms in Vietnam, and an assessment of farmers’ knowledge of proper antibiotics usage was performed. The results indicated that a quarter of tested aquaculture products were antibiotic screening test positive, and there is a general lack of knowledge about the purpose and proper usage of antibiotics by aquaculture producers. Farmers’ decision-making processes about antimicrobial use are influenced by biased sources of information, such as drug manufacturers and sellers, and by financial incentives.
Staphylococcus aureus permanently colonizes the vestibulum nasi of one-fifth of the human population, which is a risk factor for autoinfection. The precise mechanisms whereby S. aureus colonizes the ...nose are still unknown. The staphylococcal cell-wall protein clumping factor B (ClfB) promotes adhesion to squamous epithelial cells in vitro and might be a physiologically relevant colonization factor.
We define the role of the staphylococcal cytokeratin-binding protein ClfB in the colonization process by artificial inoculation of human volunteers with a wild-type strain and its single locus ClfB knock-out mutant. The wild-type strain adhered to immobilized recombinant human cytokeratin 10 (CK10) in a dose-dependent manner, whereas the ClfB(-) mutant did not. The wild-type strain, when grown to the stationary phase in a poor growth medium, adhered better to CK10, than when the same strain was grown in a nutrient-rich environment. Nasal cultures show that the mutant strain is eliminated from the nares significantly faster than the wild-type strain, with a median of 3 +/- 1 d versus 7 +/- 4 d (p = 0.006). Furthermore, the wild-type strain was still present in the nares of 3/16 volunteers at the end of follow-up, and the mutant strain was not.
The human colonization model, in combination with in vitro data, shows that the ClfB protein is a major determinant of nasal-persistent S. aureus carriage and is a candidate target molecule for decolonization strategies.
Background. Persistent nasal carriers have an increased risk of Staphylococcus aureus infection, whereas intermittent carriers and noncarriers share the same low risk. This study was performed to ...provide additional insight into staphylococcal carriage types. Methods. Fifty‐one volunteers who had been decolonized with mupirocin treatment and whose carriage state was known were colonized artificially with a mixture of S. aureus strains, and intranasal survival of S. aureus was compared between carriage groups. Antistaphylococcal antibody levels were also compared among 83 carriage‐classified volunteers. Results. Persistent carriers preferentially reselected their autologous strain from the inoculum mixture (P=.02). They could be distinguished from intermittent carriers and noncarriers on the basis of the duration of postinoculation carriage (154 vs. 14 and 4 days, respectively; P=.017, by log‐rank test). Cultures of swab samples from persistent carriers contained significantly more colony‐forming units per sample than did cultures of swab samples from intermittent carriers and noncarriers (P=.004). Analysis of serum samples showed that levels of immunoglobulin G and immunoglobulin A to 17 S. aureus antigens were equal in intermittent carriers and noncarriers but not in persistent carriers. Conclusions. Along with the previously described low risk of infection, intermittent carriers and noncarriers share similar S. aureus nasal elimination kinetics and antistaphylococcal antibody profiles. This implies a paradigm shift; apparently, there are only 2 types of nasal carriers: persistent carriers and others. This knowledge may increase our understanding of susceptibility to S. aureus infection.
Outbreaks of multidrug-resistant bacteria present a frequent threat to vulnerable patient populations in hospitals around the world. Intensive care unit (ICU) patients are particularly susceptible to ...nosocomial infections due to indwelling devices such as intravascular catheters, drains, and intratracheal tubes for mechanical ventilation. The increased vulnerability of infected ICU patients demonstrates the importance of effective outbreak management protocols to be in place. Understanding the transmission of pathogens via genotyping methods is an important tool for outbreak management. Recently, whole-genome sequencing (WGS) of pathogens has become more accessible and affordable as a tool for genotyping. Analysis of the entire pathogen genome via WGS could provide unprecedented resolution in discriminating even highly related lineages of bacteria and revolutionize outbreak analysis in hospitals. Nevertheless, clinicians have long been hesitant to implement WGS in outbreak analyses due to the expensive and cumbersome nature of early sequencing platforms. Recent improvements in sequencing technologies and analysis tools have rapidly increased the output and analysis speed as well as reduced the overall costs of WGS. In this review, we assess the feasibility of WGS technologies and bioinformatics analysis tools for nosocomial outbreak analyses and provide a comparison to conventional outbreak analysis workflows. Moreover, we review advantages and limitations of sequencing technologies and analysis tools and present a real-world example of the implementation of WGS for antimicrobial resistance analysis. We aimed to provide health care professionals with a guide to WGS outbreak analysis that highlights its benefits for hospitals and assists in the transition from conventional to WGS-based outbreak analysis.
Nontuberculous mycobacterial pulmonary disease (NTM-PD) is emerging worldwide. Currently recommended multidrug treatment regimens yield poor outcomes, and new drugs and regimens are direly needed. ...SPR719, the active moiety of SPR720, is a new benzimidazole antibiotic with limited data on antimycobacterial activity. We determined MICs and MBCs against 138 clinical and reference strains of
complex (MAC),
,
,
,
, and
and determined synergy with antimycobacterial drugs by checkerboard titrations. To study pharmacodynamics, we performed time-kill kinetics assays of SPR719 alone and in combinations against
,
, and
and assessed synergy by response surface analysis according to Bliss independence. SPR719 showed potent activity against MAC (MIC
, 2 mg/liter) and
(MIC
, 0.125 mg/liter) and modest activity against
(MIC
, 8 mg/liter); its activity is bacteriostatic and concentration-dependent. We recorded a potential for combination therapy with ethambutol against
and
and synergy with clarithromycin against
Ethambutol increased the SPR719 kill rate against
but only prevented SPR719 resistance in
SPR719 is active
against NTM; its activity is strongest against
, followed by MAC and
SPR719 shows promise for combination therapy with ethambutol against MAC and
and synergy with clarithromycin against
The parent drug SPR720 could have a role especially in MAC pulmonary disease treatment. Further studies in dynamic models and trials are ongoing to advance clinical development.
Staphylococcus aureus is a frequent cause of infections in both the community and hospital. Worldwide, the increasing resistance of this pathogen to various antibiotics complicates treatment of
S ...aureus infections. Effective measures to prevent
S aureus infections are therefore urgently needed. It has been shown that nasal carriers of
S aureus have an increased risk of acquiring an infection with this pathogen. The nose is the main ecological niche where
S aureus resides in human beings, but the determinants of the carrier state are incompletely understood. Eradication of
S aureus from nasal carriers prevents infection in specific patient categories—eg, haemodialysis and general surgery patients. However, recent randomised clinical trials in orthopaedic and non-surgical patients failed to show the efficacy of eliminating
S aureus from the nose to prevent subsequent infection. Thus we must elucidate the mechanisms behind
S aureus nasal carriage and infection to be able to develop new preventive strategies. We present an overview of the current knowledge of the determinants (both human and bacterial) and risks of
S aureus nasal carriage. Studies on the population dynamics of
S aureus are also summarised.
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