Prevalence of Nasal Colonization Among Patients With Community-Associated Methicillin-ResistantStaphylococcus aureusInfection and Their Household Contacts

2007 ◽  
Vol 28 (8) ◽  
pp. 966-969 ◽  
Author(s):  
Uzma Zafar ◽  
Leonard B. Johnson ◽  
Michel Hanna ◽  
Kathleen Riederer ◽  
Mamta Sharma ◽  
...  

Objective.To evaluate the prevalence of colonization among patients with community-associated methicillin-resistantStaphylococcus aureus(CA-MRSA) infection and their household contacts.Design.Prospective, observational laboratory study of nasal colonization among patients and their household members from September 15, 2004, to February 20, 2006.Setting.A 600-bed, urban, academic medical center.Patients.Fifty-one patients who presented with CA-MRSA infections and 49 household members had cultures of nasal swab specimens performed.Results.Skin and soft-tissue infections were seen in 50 patients (98%) and 2 household members. Twenty-one (41%) of 51 patients and 10 (20%) of 49 household members were colonized with MRSA. An additional 5 patients (10%) and 12 household members (24%) were colonized with methicillin-susceptibleStaphylococcus aureus.Most MRSA isolates (95%; infective and colonizing) carried the staphylococcal cassette chromosomemectype IV complex, and 67% represented a single clone, identical to USA 300. Of the colonized household members, 5 had isolates related to the patients' infective isolate.Conclusions.The frequency of CA-MRSA colonization among household members of patients with CA-MRSA infections is higher than rates reported among the general population. Among colonized household members, only half of the MRSA strains were related to the patients' infective isolate. Within the same household, multiple strains of CA-MRSA may be present.

2006 ◽  
Vol 27 (2) ◽  
pp. 133-138 ◽  
Author(s):  
Leonard B. Johnson ◽  
Sajjad Saeed ◽  
Joan Pawlak ◽  
Odette Manzor ◽  
Louis D. Saravolatz

Objective.To review the epidemiologic and molecular characteristics of community-associated methicillin-resistantStaphylococcus aureus(CA-MRSA) in Detroit, Michigan, to assess the risk factors for infection and the response to therapy.Design.Prospective clinical and laboratory study of 2003-2004 CA-MRSA isolates. Molecular features were compared with CA-MRSA isolates from 1980.Setting.A 600-bed urban academic medical center.Patients.Twenty-three patients with CA-MRSA infections from 2003-2004 were evaluated. In addition, laboratory analysis was performed on 13 CA-MRSA isolates from 1980.Main Outcome Measures.Laboratory analysis of isolates included antimicrobial susceptibility testing, pulsed-field genotyping, testing for Panton-Valentine leukocidin (PVL) genes, and staphylococcal cassette chromosomemectyping.Results.Patients were predominantly young African American males and presented with skin and soft-tissue infections. All isolates were resistant to erythromycin and highly susceptible to other agents. Patients were generally treated successfully with combination incision and drainage and systemic antibiotics. Among the 23 isolates, 20 (87%) were the same strain. This strain carried the staphylococcal cassette chromosomemectype IV and PVL genes and is genetically identical to USA 300. Thirteen isolates of patients from our community who presented with CA-MRSA infections in 1980 represented a single clone that is unique compared with the 2003-2004 isolates. This strain carried staphylococcal cassette chromosomemectype IVA but did not carry the PVL genes.Conclusions.In our community, CA-MRSA is largely due to a single clone with a type IVmecgene and PVL gene. The type IV staphylococcal cassette chromosomemectype can be demonstrated in CA-MRSA isolates from a remote period, suggesting that earlier outbreaks were not related to healthcare exposure.


2009 ◽  
Vol 30 (1) ◽  
pp. 4-8 ◽  
Author(s):  
Leonard B. Johnson ◽  
Jinson Jose ◽  
Farah Yousif ◽  
Joan Pawlak ◽  
Louis D. Saravolatz

Objective.To evaluate the prevalence, epidemiologic features, and molecular characteristics of colonization with community-associated methicillin-resistantStaphylococcus aureus(CA-MRSA) among hospitalized dialysis patients and their healthcare workers (HCWs).Design.Prospective observational clinical and laboratory study of nasal colonization.Setting.A 600-bed urban academic medical center.Subjects.One hundred twenty hospitalized dialysis inpatients and 100 HCWs.Results.Of 120 patients, 40 (33%) were colonized withS. aureus; 26 (65%) of these 40 were colonized with MRSA. Among the 26 MRSA isolates, 10 (38.5%) carried staphylococcal cassette chromosome (SCC)mectype IV (ie, CA-MRSA), and 7 of these 10 carried the genes for the Panton-Valentine leukocidin (PVL) toxin. Patients colonized with healthcare-associated MRSA strains and those colonized with CA-MRSA strains were similar, except for a higher frequency of a history of congestive heart failure among those with healthcare-associated MRSA strains (P= .014). Among 10 patients who presented with or developed anS. aureusinfection while hospitalized, 8 were colonized withS. aureus, 7 with MRSA, and 3 with SCCmectype IV strains. Among 100 HCWs, 31 were colonized withS. aureus, including 6 with MRSA; 2 of the MRSA isolates belonged to CA-MRSA strains, and soft-tissue infections were reported in one of the HCWs and in the family member of the other HCW colonized with these strains.Conclusions.There is a high rate of colonization with MRSA and CA-MRSA among hospitalized dialysis patients and their HCWs. As other studies have found, it appears that individuals are being colonized with both CA-MRSA strains and healthcare-associated MRSA strains.


2002 ◽  
Vol 46 (4) ◽  
pp. 1147-1152 ◽  
Author(s):  
Xiao Xue Ma ◽  
Teruyo Ito ◽  
Chuntima Tiensasitorn ◽  
Mantana Jamklang ◽  
Piriyaporn Chongtrakool ◽  
...  

ABSTRACT We identified a new type of staphylococcal cassette chromosome mec (SCCmec) from two community-acquired methicillin-resistant Staphylococcus aureus (MRSA) strains. The novel element, designated type IV SCCmec, had a unique combination of the class B mec gene complex and the type 2 ccr gene complex and was much smaller in size (21 to 24 kb) than previously identified SCCmec elements of hospital-acquired MRSA. Consistent with the strains' susceptibilities to various non-β-lactam antibiotics, the type IV SCCmec was devoid of any antibiotic resistance genes other than the mecA gene.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S149-S149
Author(s):  
Mohammed Aldhaeefi ◽  
Jeffrey Pearson ◽  
Sanjat Kanjilal ◽  
Brandon Dionne

Abstract Background Staphylococcus aureus bacteremia is a significant cause of mortality. Penicillin (PCN) may have a role in the treatment of penicillin-susceptible Staphylococcus aureus (PSSA) bacteremia as it has a narrower spectrum of activity than cefazolin and is better tolerated than antistaphylococcal penicillins (ASPs). The aim of this study is to evaluate the safety and effectiveness of PCN versus cefazolin or ASPs in the treatment of PSSA bacteremia. Methods This is a single-center, retrospective study at a tertiary academic medical center. All patients with a PSSA blood culture from January 1, 2012 to September 1, 2019 were screened. Patients were excluded if they were treated with a definitive antibiotic (defined as antimicrobial therapy received 72 hours after positive blood culture) other than the study comparators, or if they received combination antibiotic therapy >72 hours from the initial positive blood culture result. The primary outcome was 60-day clinical failure, which was a composite endpoint of change in antibiotic after 72 hours of definitive therapy, recurrence of PSSA bacteremia, infection-related readmission, or all-cause mortality. Results Of 277 patients with PSSA bacteremia, 101 patients were included in the study; 62 (61%) were male and 11 (11%) had a β-lactam allergy. At baseline, 40 patients (40%) had hardware, 25 (25%) had an intravenous line, 6 (6%) were on dialysis, and 4 (4%) had active IV drug use, with similar distribution across antibiotic groups. Penicillin was the most common antibiotic used (Table 1). There was a significant difference among groups with respect to the 60-day clinical failure (log-rank p=0.019). In terms of unadjusted 60-day clinical failure, penicillin had similar outcomes to cefazolin (95% CI -0.29 to 0.104, p=0.376), however, it had statistically significant better outcomes in comparison to the ASPs, nafcillin or oxacillin (95% CI 0.023 to 0.482, p=0.031) (Table 1). Table 1. 60-day outcomes of PSSA bacteremia Conclusion Penicillin is effective and safe in the treatment of PSSA bacteremia and may be preferable to antistaphylococcal penicillins Disclosures All Authors: No reported disclosures


2014 ◽  
Vol 5 (4) ◽  
pp. 389-395 ◽  
Author(s):  
S. Warrack ◽  
P. Panjikar ◽  
M. Duster ◽  
N. Safdar

Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen of major public health importance. Colonisation precedes infection; thus reducing MRSA carriage may be of benefit for reducing infection. Probiotics represent a novel approach to reducing MRSA carriage. We undertook a pilot feasibility randomised controlled trial of the tolerability and acceptability of probiotics for reducing nasal and intestinal carriage of MRSA. In addition, subjects were screened for vancomycin-resistant enterocococci (VRE). Subjects with a history of MRSA were recruited from a large, academic medical center and randomised to take either a placebo or probiotic (Lactobacillus rhamnosus HN001). Subjects returned to the clinic after four weeks for further testing to determine adherence to the probiotic regimen and colonisation of MRSA. 48 subjects were enrolled and randomised. Nearly 25% were transplant recipients and 30% had diabetes. The probiotic was well tolerated in the study population though minor side effects, such as nausea and bloating, were observed. A majority of the subjects randomised to HN001 had good adherence to the regimen. At the four week time point among subjects randomised to the probiotic, MRSA was detected in 67 and 50% of subjects colonised in the nares and the gastrointestinal tract, respectively. Three subjects who initially tested positive for VRE were negative after four weeks of probiotic exposure. Probiotics were well tolerated in our study population of largely immunocompromised subjects with multiple comorbidities. Adherence to the intervention was good. Probiotics should be studied further for their potential to reduce colonisation by multidrug resistant bacteria.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S263-S263
Author(s):  
Hiroki Kitagawa ◽  
Junzo Hisatsune ◽  
Hiroki Ohge ◽  
Motoyuki Sugai

Abstract Background Recently, the Japanese intrinsic community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clone (CA-MRSA/J), classified as sequence type (ST) 8 carrying staphylococcal cassette chromosome mec (SCCmec) type IVl (ST8-IVl), has been identified that causes invasive infections similar to those of USA300 clone. However, epidemiological information regarding epidemic CA-MRSA clones is limited in Japan. This study was performed to investigate the changing epidemiology of MRSA causing bacteremia in Japan. Methods We performed whole-genome sequencing of MRSA isolates causing bacteremia at Hiroshima University Hospital between January 2008 and December 2017. MRSA isolates were subjected to multilocus sequence typing, SCCmec typing and were analyzed for virulence factors. Clinical data of patients with MRSA bacteremia were analyzed. Results A total of 193 MRSA strains causing bacteremia were identified during the study period. Among these, most belonged to ST764-IIa (30%; 59 of 193) and ST5-IIa (26.9%; 52 of 193). The proportion of ST5-IIa MRSA decreased from 39.6% (42 of 106) in 2008–2012 to 11.5% (10 of 87) in 2013–2017, and that of ST764-IIa MRSA increased from 23.6% (25 of 106) to 39.1% (34 of 87) in the same time period. The proportion of CA-MRSA (MRSA carrying SCCmec type IV or V) increased from 28.3% (30 of 106) in 2008–2012 to 42.5% (37 of 87) in 2013–2017. In CA-MRSA strains, clonal complex (CC) 8-IV MRSA was predominant (76.1%; 51 of 67). Those belonging to CC8-IV MRSA isolates were ST380-IVc (18 of 51), ST8-IVl (CA-MRSA/J; 15 of 51), ST8-IVj (15 of 51), ST8-IVa (2 of 51), and ST4803-IVl (1 of 51). The rate of hospital-onset infections of ST380-IVc, ST8-IVl, and ST8-IVj were 83.3%, 46.7%, and 60%, respectively. In CA-MRSA/J strains, including their variants (e.g., ST4803-IVl), 14 of 16 strains (87.5%) carried genes for toxic shock syndrome toxin (tst-1), enterotoxin C (sec), and enterotoxin L (sel), while none of the ST380-IVc and ST8-IVj MRSA strains carried these genes. Conclusion During the study period of 10 years, predominant ST5-IIa MRSA causing hospital-onset infections was replaced by ST764-IIa MRSA. In CA-MRSA clone, ST380-IVc, ST8-IVl (CA-MRSA/J), and ST8-IVj were dominant and have already spread to the healthcare environment. Disclosures All authors: No reported disclosures.


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