Staphylococcus aureus Nasal Colonization in Spanish Children. The COSACO Nationwide Surveillance Study

Nasopharyngeal carriage, antimicrobial susceptibility patterns, and associated factors of Gram-positive bacteria among children attending the outpatient department at the University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia

BACKGROUND

Gram-positive bacteria residing in the nasopharynx can lead to severe illnesses in children, such as otitis media, pneumonia, and meningitis. Despite the potential threat, there is a lack of comprehensive data regarding the carriage rates of these bacteria among children in outpatient departments in the study area.

OBJECTIVE

This study aimed to assess the nasopharyngeal carriage, antimicrobial resistance patterns, and associated factors of Gram-positive bacteria among children attending the outpatient department at the University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia.

METHODS

A hospital-based cross-sectional study was conducted from May 1, 2023, to August 30, 2023. A total of 424 nasopharyngeal swab samples were collected using sterile nasopharyngeal swabs, inoculated on Blood Agar and Mannitol Salt Agar plates, and identified through colony morphology, Gram stain, and biochemical tests. Antimicrobial susceptibility of the identified bacterial isolates was determined employing both the Kirby-Bauer and modified Kirby-Bauer methods. D-tests were conducted using clindamycin and erythromycin discs to detect inducible clindamycin resistance, while cefoxitin disc tests were utilized to ascertain methicillin resistance. Data entry was executed using Epi-Data version 4.6, and subsequent analysis was performed utilizing SPSS version 25. Bivariable and multivariable logistic regression analyses were employed to identify associated factors. An adjusted odds ratio at a 95% confidence interval with a P-value of < 0.05 was considered statistically significant.

RESULTS

The overall nasopharyngeal carriage rate of Gram-positive bacteria was 296/424 (69.8%, 95% CI: 65.3-74.0). Staphylococcus aureus was the most prevalent 122/424 (28.8%), followed by Streptococcus pneumoniae 92/424 (21.7%). Methicillin resistance was observed in 19/122 (15.6%) of S. aureus and 3/60 (5%) of coagulase-negative staphylococcus (CoNS) species. Inducible clindamycin resistance was 10/122 (8.2%) in S. aureus and 4/53 (7.5%) in coagulase-negative staphylococcus species. Multidrug resistance was found in 146/296 (49.3%, 95% CI: 43.6-55.0) of the isolates. Associated factors with a bacterial carriage were large family size (AOR = 3.061, 95% CI: 1.595-5.874, P = 0.001), having siblings under five years old (AOR = 1.991, 95% CI: 1.196-3.313, P = 0.008), indoor cooking (AOR = 2.195, 95% CI: 1.275-3.778, P = 0.005), an illiterate mother (AOR = 3.639, 95% CI: 1.691-7.829, P = 0.001), and hospital visits (AOR = 2.690, 95% CI: 1.405-5.151, P = 0.003).

CONCLUSION

The study found a high nasopharyngeal carriage of Gram-positive bacteria in outpatient children, including notable levels of methicillin-resistant S. aureus and multi-drug-resistant isolates. Clindamycin, rifampin, and erythromycin were the most effective antimicrobials for the tested isolates. Factors contributing to bacterial carriage include visits to healthcare facilities, larger family sizes, having younger siblings, maternal illiteracy, and indoor cooking. This emphasizes the need for methicillin-resistant S. aureus surveillance in pediatric outpatient settings and community health education, especially for children's guardians. Additionally, improving household ventilation by separating kitchens from sleeping areas and regular screening of younger siblings in healthcare environments were recommended to reduce bacterial transmission within family members. The study also called for studies with advanced procedures like minimum inhibitory concentration testing and molecular characterization to better comprehend the resistance patterns and genes in circulating bacteria.

Global epidemiology of asymptomatic colonisation of methicillin-resistant Staphylococcus aureus in the upper respiratory tract of young children: a systematic review and meta-analysis

OBJECTIVE

To estimate the global prevalence of asymptomatic colonisation, and determine the associated risk factors, antibiotic resistance and genotypes of methicillin-resistant Staphylococcus aureus (MRSA) in the upper respiratory tract of young children.

DESIGN

Four bibliometric databases were searched for publications between 2010 and 2022 according to the protocol registered in PROSPERO. Cross-sectional or cohort studies describing the prevalence of asymptomatic colonisation of S. aureus and MRSA in young children were included. Data extraction and analysis were carried out by two reviewers independently according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement. Pooled prevalence was estimated using a random effects model.

SETTING AND STUDIES

We included studies where children without respiratory tract infection or Staphylococcal infection were recruited from the community, children's institutions (ie, nurseries, kindergartens, daycare centres and preschools) and healthcare centre visits and assessed for asymptomatic colonisation with S. aureus and MRSA.

MAIN OUTCOME MEASURES

The pooled prevalence of asymptomatic colonisation of S. aureus and MRSA of young children globally.

RESULTS

In this systematic review and meta-analysis of 21 416 young children, the pooled global prevalence of asymptomatic S. aureus colonisation was 25.1% (95% CI 21.4 to 28.8) and MRSA colonisation was 3.4% (95% CI 2.8 to 4.1). The clones of MRSA strains included healthcare-associated MRSA, community-associated MRSA and livestock-associated MRSA.

CONCLUSION

This study provides evidence of increased MRSA colonisation globally among young children, underlining the critical role of asymptomatic carriers in MRSA transmission and the need for control measures.

PROSPERO REGISTRATION NUMBER

CRD 42022328385.

Staphylococcus aureus Bacteremia in the Pediatric Emergency Department and Predictors of Poor Outcome

BACKGROUND

Staphylococcus aureus has become the leading cause of bacteremia among previously healthy children older than 5 years.

METHODS

We aimed to describe the infants presenting to pediatric emergency departments and diagnosed with S. aureus bacteremia (SAB) and identify predictors (clinical and laboratory variables) of poor outcome (complications, sequelae or death). We performed an observational study and subanalysis of a multicenter prospective registry, including every patient under the age of 18 years with a positive blood culture obtained at any of the 22 participating Spanish pediatric emergency departments between 2011 and 2016. We considered chronic diseases, immunosuppressive treatment and the presence of mechanical devices as risk factors for SAB.

RESULTS

Of the 229 patients with SAB, 176 (76.9%) were previously healthy, 192 (83.8%) had a normal pediatric assessment triangle and 158 (69.0%) had an associated focal infection (mainly osteoarticular infection, skin and soft tissue infection and pneumonia). Fifty-three patients (23.1%) had 1 or more risk factors for SAB. Thirty-one (13.5%) presented a poor outcome, including 4 deaths (1.7%). A poor outcome was more common in patients with SAB risk factors [odds ratio (OR): 7.0; 95% CI: 3.2-15.4], abnormal PAT (OR: 5.9; 95% CI: 2.6-13.3), elevated procalcitonin (OR: 1.2; 95% CI: 1.05-1.3) and C-reactive protein, the latter being the only independent predictor of poor outcome (OR: 1.01; 95% CI: 1.01-1.02).

CONCLUSIONS

Overall, children with SAB are previously healthy, appear well, and have an associated focal infection. One of 7 had a poor outcome, with C-reactive protein being the only predictor identified.

Factors linked to Staphylococcus aureus healthcare-associated infections among pediatric intensive care unit colonized patients

BACKGROUND

Staphylococcus aureus (SA) is one of the main pathogens responsible for healthcare-associated infection (HCAI) in pediatrics. The aim of this study was to describe the prevalence of SA-HCAI among colonized patients and the factors associated with it in the pediatric intensive care unit (PICU).

METHODS

We designed a 6-year retrospective cohort study of a PICU in a French university children's hospital including all children admitted to the PICU from January 1, 2011, to December 31, 2016, who had SA colonization on PICU admission. For each patient, the past medical history and the hospitalization data were collected. HCAIs related to SA were verified according to the criteria of the United States Centers for Disease Control and Prevention.

RESULTS

Among all patients colonized with SA (n = 1381, 26%), 105 (8%) had methicillin-resistant SA carriage and 41 (3%) developed an HCAI caused by SA. The main HCAIs were ventilator-associated pneumonia (51%) and central line-associated bloodstream infections (27%). Patients developing HCAI caused by SA had a significantly longer length of hospital stay and a higher mortality rate than the rest of the population. Using a multivariate logistic regression model, the presence of mechanical ventilation, the implementation of a surgical procedure during the PICU stay, and the onset of at least one episode of anemia during the PICU stay were significantly associated with the occurrence of HCAI due to SA.

CONCLUSION

HCAIs linked to SA carriage are rare but severe. Mechanical ventilation, surgery during the PICU stay, and anemia are factors associated with SA-HCAI.

Bloodstream Infection in Children With Epidermolysis Bullosa

BACKGROUND

Epidermolysis bullosa (EB) is frequently complicated by skin infection, which can lead to bacteremia. However, bloodstream infections (BSI) in patients with EB have not been well described.

METHODS

Retrospective study of BSI in children 0-18 years with EB from a national reference unit in Spain, in 2015-2020.

RESULTS

Among 126 children with EB, we identified 37 BSI episodes in 15 patients (14 recessive dystrophic EB, 1 junctional EB). The most frequent microorganisms were Pseudomonas aeruginosa (n = 12) and Staphylococcus aureus (n = 11). Five P. aeruginosa isolates were ceftazidime-resistant (42%), 4 of which were also resistant to meropenem and quinolones (33%). As for S. aureus, 4 (36%) were methicillin-resistant and 3 (27%) clindamycin-resistant. In 25 (68%) BSI episodes skin cultures had been performed in the previous 2 months. The most frequent isolates were also P. aeruginosa (n = 15) and S. aureus (n = 11). In 13 cases (52%), smear and blood cultures grew the same microorganism, with the same antimicrobial resistance pattern in 9 isolates. Twelve patients (10%) died during follow-up (9 RDEB and 3 JEB). BSI was the cause of death in 1 case. In patients with severe RDEB, a history of BSI was associated with higher mortality (OR 6.1, 95% CI: 1.33-27.83, P = 0.0197).

CONCLUSIONS

BSI is an important cause of morbidity in children with severe forms of EB. The most frequent microorganisms are P. aeruginosa and S. aureus, with high rates of antimicrobial resistance. Skin cultures can help guide treatment decisions in patients with EB and sepsis.

Rate of methicillin-resistant Staphylococcus aureus in pediatric emergency departments in Spain

INTRODUCTION

Staphylococcus aureus is a common germ in bacterial infections in children. The rate of methicillin-resistant S. aureus (MRSA) is increasing lately.

OBJECTIVES

The main aim is to know the rate of positive cultures to MRSA in Spanish pediatric emergency departments. The secondary aims are to analyse the risk factors for MRSA isolation (patient origin, history of hospitalization or surgery in the previous 90 days, antibiotherapy in the previous 60 days, presence of comorbidity, invasive devices, prior MRSA isolation) and to analyse the morbidity of these infections.

METHODOLOGY

Retrospective multicenter study (07/01/2017-06/30/2018) with review of patient histories with isolation of S. aureus in samples of any origin obtained in 8 pediatric emergency departments of the Infectious Diseases Working Group of the Spanish Society of pediatric Emergencies.

RESULTS

During this period, S. aureus was detected in 403 patients (average age 75.8 ± 59.2 months; 54.8% male): 28.8% hospital-related infections (HRI) and 71.2% community-related infections (CRI). Overall, MRSA rate was 16.6% (95% CI: 13-20.2%); 18.1% in HRI and 16.2% in CRI (p > 0.05). The highest rates of MRSA were obtained in skin abscesses (29.3%, CI 95%: 21.8-36.8%), patients not born in Spain (52%; CI 95%: 32-72%) or patients with a previous MRSA infection (90%; CI 95% 71.4-100%). 167 (41%) patients were admitted, 12 (3%) had complications and 4 (1%) suffered sequels. There were no deaths.

CONCLUSIONS

The overall MRSA rate was one in 6 staphylococcal infections. Higher MRSA rates were detected in samples of suppurating skin injuries and in foreign children or in children with a history of previous MRSA infection. In suppurative skin lesions, early drainage is essential and the change to an antibiotic with MRSA coverage should be considered if the evolution is inadequate.

Risk factors for antibiotic-resistant bacteria colonisation in children with chronic complex conditions

To assess drug-resistant bacterial colonisation rates and associated risk factors in children with complex chronic conditions admitted to a national reference unit in Spain. Cross-sectional study that included all children admitted to our unit from September 2018 to July 2019. Rectal swabs were obtained to determine multidrug-resistant Gram-negative bacilli (MR-GNB) colonisation, and nasal swab to determine S. aureus and methicillin-resistant S. aureus (MRSA) colonisation. Medical records were reviewed. 100 children were included, with a median of four complex chronic conditions. Sixteen percent had S. aureus colonisation, including two MRSA. S. aureus colonisation was associated with technology-dependent children, while being on antibiotic prophylaxis or having undergone antibiotic therapy in the previous month were protective factors. The prevalence of MR-GNB colonisation was 27%, which was associated with immunosuppressive therapy (aOR 31; 2.02–47]; p = 0.01), antibiotic prophylaxis (aOR 4.56; 1.4–14.86; p = 0.012), previously treated skin-infections (aOR 2.9; 1.07–8.14; p = 0.03), surgery in the previous year (aOR 1.4; 1.06–1.8; p = 0.014), and hospital admission in the previous year (aOR 1.79; [1.26–2.56]; p = 0.001). The rate of S. aureus nasal colonisation in this series was not high despite the presence of chronic conditions, and few cases corresponded to MRSA. Antibiotic prophylaxis, immunosuppressive therapies, history of infections, previous surgeries, and length of admission in the previous year were risk factors for MR-GNB colonisation.

Staphylococcus aureus Community-acquired Pneumonia in Children After 13-Valent Pneumococcal Vaccination (2008-2018): Epidemiology, Clinical Characteristics and Outcomes

BACKGROUND

The epidemiology of community-acquired pneumonia (CAP) has changed, influenced by sociosanitary conditions and vaccination status. We aimed to analyze the recent epidemiology of bacterial CAP in hospitalized children in a setting with high pneumococcal vaccination coverage and to describe the clinical characteristics of pediatric Staphylococcus aureus CAP.

METHODS

Children <17 years old hospitalized from 2008 to 2018 with bacterial CAP in 5 tertiary hospitals in Spain were included. Cases with pneumococcal CAP were randomly selected as comparative group following a case-control ratio of 2:1 with S. aureus CAP.

RESULTS

A total of 313 bacterial CAP were diagnosed: Streptococcus pneumoniae CAP (n = 236, 75.4%), Streptococcus pyogenes CAP (n = 43, 13.7%) and S. aureus CAP (n = 34, 10.9%). Throughout the study period, the prevalence of S. pyogenes increased (annual percentage change: +16.1% [95% CI: 1.7-32.4], P = 0.031), S. pneumoniae decreased (annual percentage change: -4.4% [95 CI: -8.8 to 0.2], P = 0.057) and S. aureus remained stable. Nine isolates of S. aureus (26.5%) were methicillin-resistant. Seventeen cases (50%) with S. aureus CAP had some pulmonary complication and 21 (61.7%) required intensive care. S. pneumoniae CAP showed a trend toward higher prevalence of pulmonary complications compared with S. aureus CAP (69.1% vs. 50.0%, P = 0.060), including higher frequency of pulmonary necrosis (32.4% vs. 5.9%, P = 0.003).

CONCLUSIONS

The incidence of S. aureus CAP in children remained stable, whereas the prevalence of pneumococcal CAP decreased and S. pyogenes CAP increased. Patients with S. aureus presented a high frequency of severe outcomes, but a lower risk of pulmonary complications than patients with S. pneumoniae.

Characterization of methicillin-resistant Staphylococcus aureus strains colonizing the nostrils of Spanish children

OBJECTIVE

To characterize the Staphylococcus aureus strains colonizing healthy Spanish children.

METHODS

Between March and July 2018, 1876 Spanish children younger than 14 years attending primary healthcare centers were recruited from rural and urban areas. Staphylococcus aureus colonization of the anterior nostrils was analyzed. MecA and mecC genes, antibiotic susceptibility, and genotyping according to the spa were determined in all strains, and the following toxins were examined: Panton-Valentine leucocidin (pvl), toxic shock syndrome toxin (tst), and exfoliative toxins (eta, etb, etd). Multilocus sequence typing (MLST) and staphylococcal cassette chromosome (SCCmec) typing were performed on methicillin-resistant Staphylococcus aureus (MRSA) strains, as well as pulsed-field gel electrophoresis (PFGE).

RESULTS

619 strains were isolated in 1876 children (33%), and 92% of them were sent for characterization to the Spanish National Centre of Microbiology (n = 572). Twenty (3.5%) of these strains were mecA-positive. Several spa types were detected among MRSA, being t002 the most frequently observed (30%), associating with SCCmec IVc. Among MSSA, 33% were positive for tst, while only 0.73% were positive for pvl. The 20 MRSA strains were negative for pvl, and 6 (30%) harbored the tst gene.

CONCLUSIONS

methicillin-resistant Staphylococcus aureus nasal colonization in Spanish children is rare, with t002 being the most observed spa type, associated with SCCmec IVc. None of the MRSA strains produced pvl, but up to 30% of S. aureus strains were positive for tst.

[Rate of methicillin-resistant Staphylococcus aureus in pediatric emergency departments in Spain]

INTRODUCTION

Staphylococcusaureus (S. aureus) is a common germ present in bacterial infections in children. Lately, the rate of methicillin-resistant S. aureus (MRSA) is increasing.

OBJECTIVES

The main aim of this study is to know the rate of positive cultures to MRSA in Spanish pediatric emergency departments. The secondary aims are to analyze the risk factors for MRSA isolation (patient origin, history of hospitalization or surgery in the previous 90 days, antibiotherapy in the previous 60 days, presence of comorbidity, invasive devices, prior MRSA isolation) and to analyze the morbidity of these infections.

METHODOLOGY

Retrospective multicenter study (07/01/2017-06/30/2018) with review of patient histories with isolation of S. aureus in samples of any origin obtained in 8 pediatric emergency departments of the Infectious Diseases Working Group of the Spanish Society of Pediatric Emergencies.

RESULTS

During this period, S. aureus was detected in 403 patients (average age 75.8±59.2 months; 54.8% male): 28.8% hospital-related infections and 71.2% community-related infections. Overall, MRSA rate was 16.6% (95% CI: 13-20.2%); 18.1% in hospital-related infections and 16.2% in community-related infections (P>.05). The highest rates of MRSA were obtained in skin abscesses (29.3%, 95% CI: 21.8-36.8%), patients not born in Spain (52%; 95% CI: 32-72%) or patients with a previous MRSA infection (90%; 95% CI: 71.4-100%). 167 (41%) patients were admitted, 12 (3%) had complications and 4 (1%) suffered sequels. There were no deaths.

CONCLUSIONS

The overall MRSA rate was one in six staphylococcal infections. Higher MRSA rates were detected in samples of suppurating skin injuries and in foreign children or in children with a history of previous MRSA infection. In suppurative skin lesions, early drainage is essential and the change to an antibiotic with MRSA coverage should be considered if the evolution is inadequate.