Prevalence of methicillin-resistant Staphylococcus aureus nasal carriage in patients admitted to Driscoll Children's Hospital

Decrease in the Prevalence of Methicillin-Resistant Staphylococcus Aureus Nasal Colonization of Children Admitted to Driscoll Children's Hospital

Compared with a similar 2005 study, this 2016 study showed a significant decrease from 22% to 3% in the prevalence of methicillin-resistant Staphylococcus aureus nasal colonization in children admitted to our facility. Of the sampled 360 children, 21% were colonized with S. aureus and 14% of those isolates were methicillin-resistant S. aureus, whereas 61% of the isolates in 2005 were methicillin-resistant S. aureus.

A Novel Protocol for Contact Isolation for Multidrug-Resistant Organisms in Children on Inpatient Rehabilitation and Effects on Functional Outcomes: A Noninferiority Study

BACKGROUND

The incidence of contact isolation for multidrug-resistant organisms is increasing in acute hospitals and inpatient rehabilitation units alike. There is limited evidence on the effect of contact isolation on functional outcomes during inpatient rehabilitation.

OBJECTIVE

To determine whether the use of a modified contact isolation protocol (MCI) resulted in noninferior functional outcomes compared with children without contact isolation (NCI) on inpatient rehabilitation.

DESIGN

This is a retrospective noninferiority study.

SETTING

One academically affiliated pediatric inpatient rehabilitation unit located in a children's hospital.

PATIENTS

All children with any diagnosis admitted to inpatient rehabilitation from January 1, 2007, to December 31, 2014.

METHODS OR INTERVENTIONS

We compared functional outcomes for 2 groups of children.

MAIN OUTCOME MEASUREMENTS

Primary outcome measures included the Functional Independence Measure for Children (WeeFIM) efficiency and the change in the Developmental Functional Quotient (DFQ) for the WeeFIM. Noninferiority margins of 0.63 for the WeeFIM efficiency and 0.092 for the change in DFQ for the WeeFIM were used.

RESULTS

There were a total of 949 patients of whom 899 were NCI, 48 MCI, and 2 excluded due to missing information. Patients with MCI had functional outcomes that were noninferior to those with NCI including the WeeFIM efficiency (mean difference 0.002, 95% CI -0.38 to 0.404) and the change in DFQ for the WeeFIM (mean difference -0.05, 95% CI -0.058 to 0.003).

CONCLUSIONS

The modified contact isolation protocol, having resulted in noninferior functional outcomes in inpatient rehabilitation may provide adequate contact isolation while allowing for noninferior functional outcomes. This may be a guide in the face of an ever-increasing need for contact isolation.

LEVEL OF EVIDENCE

III.

Risk Factors Associated With Abscess Formation in Children 5 Years of Age and Younger

From 1997 to 2009, hospitalization rates have doubled for pediatric patients with soft tissue abscesses requiring incision and drainage. Despite this increasing national burden, few studies have been conducted to identify the risk factors associated with abscess formation. Our study evaluates a collection of physiological and lifestyle parameters that may serve as risk factors for abscess formation among pediatric patients 5 years of age or younger. Our results indicate family history and age 2 years and younger are associated with higher risk of abscess formation. Furthermore, methicillin-resistant Staphylococcus aureus and methicillin-susceptible Staphylococcus aureus were prevalent pathogens associated with abscess in our study group. Pediatricians may employ these novel parameters to educate parents and/or guardians of high-risk groups on preventing abscess formation to alleviate the burden of incision & dragining requiring abscess on health care costs.

Prevalence of Community-Acquired Methicillin-Resistant Staphylococcus aureus Nasal Colonization Among Children

BACKGROUND

Invasive infections from community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) are increasingly being encountered in healthy children. Nasal colonization of MRSA is associated with increased risk for acquiring invasive disease. The objective of this study was to determine prevalence and risk factors for CA-MRSA nasal colonization among a healthy paediatric population and to determine antibiotic susceptibilities of S. aureus isolates.

MATERIALS AND METHODS

Using a cross-sectional study design, children aged 1mnth-17y attending well-child clinic at an academic hospital and a local public school in Mangalore, India were screened for S. aureus colonization via nasal swabs. A questionnaire was administered and data on risk factors for nasal colonization was collected. Samples were obtained from the anterior nares and cultured quantitatively. S. aureus isolates were confirmed by growth on selective media and coagulase testing. Disk diffusion antibiotic susceptibility tests were performed according to Clinical and Laboratory Standard Institute guidelines.

RESULTS

Of the 500 children included in the study, S. aureus was isolated from the anterior nares in 126 (25%) children; four (3%) isolates were classified as CA-MRSA. Factors associated with S. aureus nasal colonization were children <6 y old (p=0.030) and members of joint families (p=0.044). Resistance to many classes of antibiotics were noted among S. aureus isolates including trimethoprim-sulfamethoxazole (39%), ciprofloxacin (16%), erythromycin (19%) and clindamycin (5%). Inducible clindamycin resistance (positive D test) was detected in 11 of the erythromycin-resistant strains not already classified as resistant to clindamycin. No resistance to vancomycin was observed.

CONCLUSION

Children in India have a high rate of nasal colonization of S. aureus. Nasal colonization of community-associated methicillin-resistant S. aureus exists but is still low among healthy children. The high rate of resistance to many classes of antibiotics among S. aureus strains is of great concern warranting continued surveillance and antimicrobial stewardship.

Nasal carriage of multi-drug resistant Panton-Valentine leucocidin-positive methicillin-resistant Staphylococcus aureus in children in Tripoli-Libya

Methicillin-resistant Staphylococcus aureus (MRSA) colonized children are at an increased risk of developing infections than methicillin-sensitive S. aureus colonized children. Nasal specimens from inpatient children, mothers of inpatient children, healthcare workers, and outpatient children at Tripoli Children Hospital (TCH) were examined for MRSA by chromogenic MRSA ID medium. Susceptibility of MRSA isolates to antibiotics was determined by the disc diffusion method. The nasal carriage rate of MRSA among inpatient children (8.3%, 24 of 289), their mothers (11%, 22 of 200), and healthcare workers (12.4%, 22 of 178) was significantly higher than among outpatient children (2.2%, 2 of 91) (P < 0.05, P < 0.02, and P < 0.006, respectively). Of the examined MRSA isolates (N = 35) 10 (28.6%) were positive for Panton-Valentine leucocidin genes by polymerase chain reaction. Multidrug resistance was found in 24.3% (17 of 70) of MRSA isolates. Nasal carriage of multidrug-resistant Panton-Valentine leucocidin-positive MRSA is not uncommon among inpatient children and their mothers in Tripoli.

Methicillin-resistant Staphylococcus aureus colonization among health care workers in a downtown emergency department in Toronto, Ontario

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) acquired in the community, otherwise known as community-acquired MRSA, has emerged rapidly in recent years. Colonization with MRSA has been associated with an increased risk of symptomatic and serious infections and, in some settings, health care workers (HCWs) exhibit a higher prevalence of MRSA colonization.

OBJECTIVE

To determine MRSA colonization in emergency department (ED) HCWs in the setting of a moderate prevalence of MRSA in skin and soft tissue infections.

METHODS

The present study was conducted at a downtown ED in Toronto, Ontario. ED HCWs completed a brief questionnaire and swabs were taken from one anterior nare, one axilla and any open wounds (if present). Swabs were processed using standard laboratory techniques.

RESULTS

None of the 89 staff (registered nurses [n=55], physicians [n=15], other [n=19]) were MRSA positive and 25 (28.1%) were colonized with methicillin-susceptible S aureus.

CONCLUSIONS

Contrary to common belief among HCWs and previous studies documenting MRSA colonization of HCWs, MRSA colonization of this particular Canadian ED HCW cohort was very low and similar to that of the local population.

Prevalence and antibiotic susceptibility pattern of methicillin-resistant Staphylococcus aureus (MRSA) among primary school children and prisoners in Jimma Town, Southwest Ethiopia

BACKGROUND

Staphylococcus aureus infections are increasingly reported from both health institutions and communities around the world. In particular, infections due to methicillin-resistant Staphylococcus aureus (MRSA) strains have been detected worldwide. If MRSA becomes the most common form of S. aureus in a community, it makes the treatment of common infections much more difficult. But, report on the current status of community acquired MRSA in the study area is scanty.

METHODS

Community-based cross sectional study was conducted to evaluate the current prevalence and antibiotic susceptibility pattern of MRSA among primary school children and prisoners in Jimma town. MRSA was detected using Cefoxitin (30μg) disc; and epidemiologic risk factors were assessed using pre-designed questionnaires distributed to the children's parents and prisoners. A total of 354 nasal swabs were collected from primary school children and prisoners from December 2010 to March 2011 following standards microbiological methods.

RESULTS

A total of 169 S. aureus isolates were recovered. The overall prevalence of MRSA among the study population was 23.08 % (39/169). Specifically, the prevalence of MRSA among primary school children and prisoners were 18.8% (27/144) and 48% (12/25), respectively. The isolated S. aureus and MRSA displayed multiple drug resistance (MDR) to 2 to 10 antibiotics. The most frequent MDR was Amp/Bac/Ery/Pen/Fox (resistance to Ampicillin, Bacitracin, Erythromycin, Penicillin, and Cefoxitin).

CONCLUSION

The present study revealed that MRSA could be prevalent in the healthy community, transmitted from hospital to the community. The high distribution of MRSA could be favored by potential risk factors. Thus, for comprehensive evaluation of the current prevalence of MRSA and design control measures, consideration need to be given to the healthy community besides data coming from health institutions.

Methicillin-resistant Staphylococcus aureus colonization in a pediatric intensive care unit: risk factors

BACKGROUND

Both methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant Streptococcus pneumoniae have become significant causes of disease, both in health care and community settings.

OBJECTIVES

All patients admitted to our pediatric intensive care unit (PICU) currently had a rapid test for methicillin-resistant Staphylococcus aureus (MRSA) performed as per hospital guidelines. This study looked at risk factors for colonization.

METHODS

Nasal swabs were tested for MRSA on all admissions to the PICU from May 2008 to September 2009 using polymerase chain reaction as per hospital guidelines. All patients enrolled were placed in either a MRSA-positive or a MRSA-negative group, which were compared with each other. Risk factors were assessed from a questionnaire and the resident history.

RESULTS

The prevalence of MRSA colonization in our study was 4.5%. Six hundred sixty-six patients were negative for MRSA, and 31 were positive. Patients in the MRSA colonization group were younger, more likely had family (household members) employed in medicine, and were more likely hospitalized or had undergone surgery within the previous 12 months. Prolonged neonatal intensive care unit stay (>1 week) was associated with MRSA colonization (P < .001).

CONCLUSION

The percentage of patients positive for MRSA admitted to a PICU is low. Recent exposure to the health care system, especially a stay in the neonatal intensive care unit, is associated with an increased risk of colonization.

Molecular distinctions exist between community-associated methicillin-resistant Staphylococcus aureus colonization and disease-associated isolates in children

OBJECTIVE

To define the molecular epidemiology of colonization and disease-associated isolates of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA).

DESIGN

Laboratory-based comparative study of clinical staphylococcal isolates.

METHODS

We analyzed 255 pediatric CA-MRSA isolates for molecular characteristics associated with colonization and disease. We used polymerase chain reaction to determine the presence of Panton-Valentine Leukocidin and the lantibiotic element, bsaB, and to characterize the staphylococcal cassette chromosome mec type and accessory gene regulator locus. Pulsed-field gel electrophoresis was used to determine genetic relatedness between strains.

RESULTS

A total of 150 isolates were obtained from patients with clinical disease (37 invasive infections, 113 noninvasive infections) and 105 from subjects with nasal colonization alone. Of 150 disease-associated isolates, 123 (82%) belonged to pulsed-field gel electrophoresis group USA300, whereas only 19 (18%) of 105 colonization isolates were of the USA300 lineage. Colonization isolates were less likely to possess staphylococcal cassette chromosome mec type IV, Panton-Valentine Leukocidin, or agr type 1 (P < 0.001).

CONCLUSIONS

Colonization strains of CA-MRSA in children differ significantly from those strains recovered from patients with staphylococcal infections. This suggests that only colonization with specific strain types, rather than methicillin-resistant Staphylococcus aureus colonization in general, increases the risk for CA-MRSA disease.

Staphylococcus aureus: a continuously evolving and formidable pathogen in the neonatal intensive care unit

Staphylococcus aureus is a continuously evolving and formidable pathogen that has been a problem for both healthy and sick neonates for decades. Much focus over the past 20 years has been on hospital-associated methicillin-resistant S aureus (HA-MRSA); however, a global epidemic because of virulent community-associated MRSA (CA-MRSA) that has no "fitness cost" for carrying antibiotic-resistance genes has moved into neonatal intensive care units (NICUs). Recently, methicillin-susceptible S aureus has adopted some of the virulence factors of CA-MRSA and is an increasingly common cause of hospital-acquired infections in NICUs. This article reviews the changing epidemiology, clinical manifestations, and treatment of S aureus in neonates.

Community-associated methicillin-resistant Staphylococcus aureus: epidemiology and clinical consequences of an emerging epidemic

Staphylococcus aureus is an important cause of skin and soft-tissue infections (SSTIs), endovascular infections, pneumonia, septic arthritis, endocarditis, osteomyelitis, foreign-body infections, and sepsis. Methicillin-resistant S. aureus (MRSA) isolates were once confined largely to hospitals, other health care environments, and patients frequenting these facilities. Since the mid-1990s, however, there has been an explosion in the number of MRSA infections reported in populations lacking risk factors for exposure to the health care system. This increase in the incidence of MRSA infection has been associated with the recognition of new MRSA clones known as community-associated MRSA (CA-MRSA). CA-MRSA strains differ from the older, health care-associated MRSA strains; they infect a different group of patients, they cause different clinical syndromes, they differ in antimicrobial susceptibility patterns, they spread rapidly among healthy people in the community, and they frequently cause infections in health care environments as well. This review details what is known about the epidemiology of CA-MRSA strains and the clinical spectrum of infectious syndromes associated with them that ranges from a commensal state to severe, overwhelming infection. It also addresses the therapy of these infections and strategies for their prevention.

Community-associated methicillin-resistant Staphylococcus aureus strains in pediatric intensive care unit

Virulent community-associated methicillin-resistant Staphylococcus-aureus (CA-MRSA) strains have spread rapidly in the United States. To characterize the degree to which CA-MRSA strains are imported into and transmitted in pediatric intensive care units (PICU), we performed a retrospective study of children admitted to The Johns Hopkins Hospital PICU, March 1, 2007-May 31, 2008. We found that 72 (6%) of 1,674 PICU patients were colonized with MRSA. MRSA-colonized patients were more likely to be younger (median age 3 years vs. 5 years; p = 0.02) and African American (p<0.001) and to have been hospitalized within 12 months (p<0.001) than were noncolonized patients. MRSA isolates from 66 (92%) colonized patients were fingerprinted; 40 (61%) were genotypically CA-MRSA strains. CA-MRSA strains were isolated from 50% of patients who became colonized with MRSA and caused the only hospital-acquired MRSA catheter-associated bloodstream infection in the cohort. Epidemic CA-MRSA strains are becoming endemic to PICUs, can be transmitted to hospitalized children, and can cause invasive hospital-acquired infections. Further appraisal of MRSA control is needed.

The development and validation of a simulation tool for health policy decision making

Computer simulations have been used to model infectious diseases to examine the outcomes of alternative strategies for managing their spread. Methicillin resistant Staphylococcus aureus (MRSA) skin and soft tissue infections have become prominent in many communities and efforts are underway to reduce the spread of this organism both in hospitals and communities. Currently, there are few tools for policy makers to use to examine the outcome of various choices when making decisions about MRSA. Using the example of MRSA, we describe, in this paper, a rigorous approach for development and validation of a tool that simulates the spread of MRSA infections. We used sensitivity analyses in a novel way and validated the simulation results against local data over time. Our approach for simulation development and validation is generalizeable to simulations of other diseases.

Importance of colonization site in the current epidemic of staphylococcal skin abscesses

OBJECTIVE

The goal was to compare rectal and nasal Staphylococcus aureus colonization rates and S aureus pulsed-field types (PFTs) for children with S aureus skin and soft-tissue abscesses and normal control subjects.

METHODS

Sixty consecutive children with S aureus skin and soft-tissue abscesses that required surgical drainage and 90 control subjects were enrolled. Cultures of the nares and rectum were taken in both groups. S aureus isolates from all sites were characterized through multiple-locus, variable-number, tandem-repeat analysis, pulsed-field gel electrophoresis, staphylococcal cassette chromosome mec typing for methicillin-resistant S aureus isolates, and determination of the presence of Panton-Valentine leukocidin genes.

RESULTS

S aureus was detected significantly more often in the rectum of children with abscesses (47%) compared with those in the control group (1%; P = .0001). Rates of nasal colonization with S aureus were equivalent for children with abscesses (27%) and control subjects (20%; P = .33). S aureus recovered from the rectum was identical to S aureus in the abscess in 88% of cases, compared with 75% of nasal isolates. PFT USA300, staphylococcal cassette chromosome mec type IV, and Panton-Valentine leukocidin genes were significantly increased in the S aureus isolates from children with abscesses compared with those from control subjects.

CONCLUSIONS

Skin and soft-tissue abscesses in the current epidemic of community-associated staphylococcal disease are strongly associated with rectal colonization by PFT USA300. Nasal colonization in children does not seem to be a risk factor.

Staphylococcus aureus colonization of anterior nares of school going children

OBJECTIVE

To determine the colonization rates of S. aureus in anterior nares of school going children, evaluate the antimicrobial resistance of such isolates against various antibiotics.

METHODS

Nasal swabs taken for S. aureus in 392 healthy school going children aged between 5 and 15 yr belonging to three schools surrounding Kamineni Institute of Medical Sciences, Narketpally, Andhra Pradesh, India. Swabs were inoculated in to Mannitol Salt Agar (MSA) and incubation at 37 degrees C for 24hr, Staphylococcus aureus isolates were identified by standard microbiological methods such as Gram's stain, catalase and coagulase. MICs were determined by Agar dilution technique against Vancomycin, Ciprofloxacin, Sparfloxacin, Sparfloxacin beta Cyclodextrin. Antimicrobial resistance patterns of all the isolates against Oxacillin (1 microg) Penicillin (10 units), Ampicillin (10 microg), Co-trimoxazole (23.75 microg), Erythromycin (15 microg), Tetracycline (30 microg) and Gentamicin (10 microg) were tested using Kirby-Baeur disk diffusion method in accordance with CLSI standards.

RESULTS

Of the 392 samples screened 63(16%) showed the growth of Staphylococcus aureus. 12(19%) isolates were found to be MRSA. Antimicrobial susceptibility testing using Agar dilution method against Vancomycin, ciprofloxacin, Sparfloxacin, and Sparfloxacin beta Cyclodextrin revealed MICs in the range of 0.52 microg/ml, 0.51 microg/ml, 0.5 microg/ml and <0.0312-0.250 microg/ml respectively. Disk diffusion method showed that all the isolates were resistant to Penicillin and Ampicillin. A resistance of 14.3%, 25% and 22.2% was observed against Co-trimoxazole, Erythromycin and Tetracycline respectively. Gentamiicin was the only antibiotic against which most of the isolates were sensitive.

CONCLUSION

Our results suggests that healthy school going children under 16 yr of age are potential carriers of S. aureus and in particular MRSA and multi-drug resistant strains.

Current issues in the management of sinonasal methicillin-resistant Staphylococcus aureus

PURPOSE OF REVIEW

Staphylococcus aureus is an important pathogen, contributing to both pediatric and adult infections in the USA. In recent years, methicillin-resistant Staphylococcus aureus (MRSA) has become a source of public fear and outcry. In this article, we review facts and fiction of sinonasal MRSA.

RECENT FINDINGS

Although the exact role of bacteria in chronic rhinosinusitis continues to be debated, the role of MRSA in these patients is even less apparent. When MRSA is involved, there are few to guide treatment. Oral, parenteral, and topical antibiotics are all used in the treatment of sinonasal MRSA. MRSA eradication has been advocated by some; however, there are few data to support the efficacy of eradication. Current treatment regimens by the authors are reviewed.

SUMMARY

There is much that is not known about the role of MRSA in sinonasal infection, and the impact of sinonasal MRSA on the health quality of the community also remains undefined. Treatment outlines are presented; however, with the current state of data, these treatment preferences lack a solid, evidence-based foundation that is favored. Future studies will lay the foundation for more rigorously supported treatment algorithms.

Discordance between Staphylococcus aureus nasal colonization and skin infections in children

We examined nasal carriage of Staphylococcus aureus in otherwise healthy children presenting with skin and soft tissue infections. We found high rates of nasal colonization with S. aureus, but significant discordance between nasal and wound isolates. Recurrent skin and soft tissue infections were common but unrelated to baseline methicillin-resistant S. aureus nasal colonization status.

Prevalence of methicillin-resistant Staphylococcus aureus nasal carriage in healthcare workers

Thirty (12%) of 257 healthcare workers were colonized with methicillin-resistant Staphylococcus aureus (MRSA). There was no significant difference in MRSA colonization among physicians (13%), nurses (12%), and other healthcare professionals (11%). Potential risk factors for MRSA colonization were found in 90% or more of all subjects, including those with MRSA and methicillin-susceptible S. aureus nasal carriage, as well as in persons who were not colonized.

Influenza-associated pediatric mortality in the United States: increase of Staphylococcus aureus coinfection

OBJECTIVE

Pediatric influenza-associated death became a nationally notifiable condition in the United States during 2004. We describe influenza-associated pediatric mortality from 2004 to 2007, including an increase of Staphylococcus aureus coinfections.

METHODS

Influenza-associated pediatric death is defined as a death of a child who is younger than 18 years and has laboratory-confirmed influenza. State and local health departments report to the Centers for Disease Control and Prevention demographic, clinical, and laboratory data on influenza-associated pediatric deaths.

RESULTS

During the 2004-2007 influenza seasons, 166 influenza-associated pediatric deaths were reported (n = 47, 46, and 73, respectively). Median age of the children was 5 years. Children often progressed rapidly to death; 45% died within 72 hours of onset, including 43% who died at home or in an emergency department. Of 90 children who were recommended for influenza vaccination, only 5 (6%) were fully vaccinated. Reports of bacterial coinfection increased substantially from 2004-2005 to 2006-2007 (6%, 15%, and 34%, respectively). S aureus was isolated from a sterile site or endotracheal tube culture in 1 case in 2004-2005, 3 cases in 2005-2006, and 22 cases in 2006-2007; 64% were methicillin-resistant S aureus. Children with S aureus coinfection were significantly older and more likely to have pneumonia and acute respiratory distress syndrome than those who were not coinfected.

CONCLUSIONS

Influenza-associated pediatric mortality is rare, but the proportion of S aureus coinfection identified increased fivefold over the past 3 seasons. Research is needed to identify risk factors for influenza coinfection with invasive bacteria and to determine the impact of influenza vaccination and antiviral agents in preventing pediatric mortality.

Variability among pediatric infectious diseases specialists in the treatment and prevention of methicillin-resistant Staphylococcus aureus skin and soft tissue infections

There are currently no clear consensus recommendations for the treatment and prevention of community-associated methicillin-resistant Staphylococcus aureus skin and soft tissue infections in pediatric patients. We surveyed over 100 Pediatric Infectious Diseases consultants and found considerable variability in both the treatment of skin and soft tissue infections and the strategies used for the management of children with recurrent MRSA disease.

A review of community-associated methicillin-resistant Staphylococcus aureus skin and soft tissue infections

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a cause of infection among otherwise healthy children and adults in the community. Skin and soft tissue infections are most common, but invasive manifestations also occur. A limited number of strains that may possess unique virulence or transmissibility factors have accounted for the majority of these infections. These strains emerged in the community but now are being transmitted in both community and healthcare settings. Incision and drainage remains the primary treatment for skin abscesses. Strains of MRSA circulating in the community generally are susceptible to a number of nonbeta-lactam antimicrobial agents, although resistance patterns may vary temporally and geographically. Educating patients on strategies to prevent further transmission is a critical component of case management. More data are needed to determine optimal strategies for management and prevention of MRSA skin infections in the community.

Nasal carriage of a single clone of community-acquired methicillin-resistant Staphylococcus aureus among kindergarten attendees in northern Taiwan

Background:

To evaluate the prevalence and microbiological characterization of community-acquired (CA) methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage in a kindergarten.

Methods:

Point prevalence study. Nasal swabs were collected from healthy children younger than 7 years of age who were attending a kindergarten in Taipei, Taiwan. A parent questionnaire regarding MRSA risk factors was administered simultaneously. All CA-MRSA colonization isolates were archived for subsequent antimicrobial susceptibility and molecular typing.

Results:

Of the 68 children who participated in the study, 17 (25%) had S. aureus isolated from nasal swabs. Nine (13.2%) of the 68 children had CA-MRSA carriage, and none of them had any identified risk factors. Antimicrobial susceptibility testing revealed all of the 9 CA-MRSA colonization isolates had uniformly high resistance (100%) to both clindamycin and erythromycin, the macrolide-lincosamide-streptogramin-constitutive phenotype and the ermB gene. Pulsed-field gel electrophoresis revealed 8 (88.9%) of 9 CA-MRSA colonization isolates were genetically related and multilocus sequence typing revealed all isolates had sequence type 59. All of the colonization isolates carried the staphylococcal cassette chromosome mec type IV, but none were positive for the Panton-Valentine leukocidin genes.

Conclusion:

The results of this study suggest that a single predominant CA-MRSA colonization strain featuring high clindamycin resistance circulated in this kindergarten. Additionally, due to the established transmissibility of colonization isolates, the high prevalence of nasal carriage of CA-MRSA among healthy attendees in kindergartens may indicate the accelerated spread of CA-MRSA in the community.

Carriage of methicillin-resistant Staphylococcus aureus in children in Brazil

The extent of methicillin-resistant Staphylococcus aureus (MRSA) carriage in Brazilian infants is largely unknown. We evaluated the presence of MRSA nasopharyngeal (NP) carriage in 686 children younger than 5 years with respiratory tract infection (609) and meningitis (77). S. aureus was isolated in 93 (13.5%) NP specimens of which 7 (1.02%) were identified as MRSA (oxacillin MIC, >256 microg/mL) harboring SCCmec type III. The dendrogram derived from the pulsed-field gel electrophoresis gel images showed that the MRSA strains diverged from the Brazilian endemic hospital-acquired clones from 10.4% to 21.7%. Although the MRSA strains were recovered from children within the first 6 h of their admission to hospital, the presence of SCCmec type III along with the multidrug-resistant profile of the isolates raises the hypotheses that these MRSA strains may have hospital origin and are now spreading into the pediatric community as colonizing pathogens.