Methicillin-Resistant Staphylococcus aureus Nasal Colonization in Chinese Children: A Prevalence Meta-Analysis and Review of Influencing Factors

The Correlation Between Biofilm-Forming Ability of Community-Acquired Methicillin-Resistant Staphylococcus aureus Isolated from the Respiratory Tract and Clinical Characteristics in Children

Objective

This study aimed to investigate the biofilm-forming ability, molecular typing, and antimicrobial resistance of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) strains isolated from the respiratory tract of children and their correlation with clinical characteristics.

Methods

All CA-MRSA strains were isolated from hospitalized children, and their presentation, molecular typing, antimicrobial susceptibility, and biofilm formation were investigated. The clinical characteristics were compared between the strong and weak biofilm producer groups.

Results

Fifty-three CA-MRSA strains were isolated from the respiratory samples of 53 children, with nearly half of them being young infants (0-12 months). Approximately, 88.7% (47/53) of the isolates were resistant to four or more antibiotics, mainly β-lactam antibiotics, lincosamides, and macrolides. Twelve sequence types (STs) and 20 subtypes of staphylococcal protein A (spa) typing were identified, with ST59-t437 (39.6%, 21/53) as the predominant subtype. All strains showed the ability to form biofilms. When compared to children with weak biofilm-forming CA-MRSA strains, those with strong biofilm-forming strains had higher proportions of lower respiratory tract infections (LRTI) (88.5% vs 59.3%), obvious cough symptoms (84.6% vs 51.9%), and severe chest imaging manifestations (76.9% vs 37.0%). Furthermore, a strong biofilm-forming ability significantly increased the risk of prolonged cough in children with LRTI (44.4% vs 14.3%), and a positive correlation between the duration of cough and the extent of biofilm formation was observed. Medical history investigation revealed that the strong biofilm-forming group had a much higher percentage of macrolides intake than the weak biofilm-forming group in the last month before admission (61.5% vs 14.8%).

Conclusion

ST59-t437 was the most prevalent clone in CA-MRSA respiratory isolates among the hospitalized children. All CA-MRSA strains formed biofilms. The stronger the biofilm-forming ability, the more serious and prolonged were the respiratory symptoms.

High Fecal Carriage of Multidrug Resistant Bacteria in the Community among Children in Northwestern Tanzania

Colonization of multidrug resistant (MDR) bacteria is associated with subsequent invasive infections in children with comorbidities. This study aimed to determine the resistance profile and factors associated with MDR pathogen colonization among HIV−and HIV+ children below five years of age in Mwanza, Tanzania. A total of 399 (HIV− 255 and HIV+ 144) children were enrolled and investigated for the presence of MDR bacteria. The median [IQR] age of children was 19 (10–36) months. Out of 27 Staphylococcus aureus colonizing the nasal cavity, 16 (59.5%) were methicillin resistant while 132/278 (47.2%) of Enterobacteriaceae from rectal swabs were resistant to third generation cephalosporins, with 69.7% (92/132) exhibiting extended spectrum beta lactamase (ESBL) phenotypes. The proportion of resistance to gentamicin, amoxicillin/clavulanic acid and meropenem were significantly higher among HIV+ than HIV− children. A history of antibiotic use in the last month OR 2.62 [1.1, 6.9] (p = 0.04) and history of a relative admitted from the same household in the past three months OR 3.73 [1.1, 13.2] (p = 0.03) independently predicted ESBL rectal colonization. HIV+ children had significantly more fecal carriage of isolates resistant to uncommonly used antibiotics. There is a need to strengthen antimicrobial stewardship and Infection Prevention and Control (IPC) programs to prevent the emergence and spread of MDR pathogens in children.

Staphylococcus aureus-A Known Opponent against Host Defense Mechanisms and Vaccine Development-Do We Still Have a Chance to Win?

The main purpose of this review is to present justification for the urgent need to implement specific prophylaxis of invasive Staphylococcus aureus infections. We emphasize the difficulties in achieving this goal due to numerous S. aureus virulence factors important for the process of infection and the remarkable ability of these bacteria to avoid host defense mechanisms. We precede these considerations with a brief overview of the global necessitiy to intensify the use of vaccines against other pathogens as well, particularly in light of an impasse in antibiotic therapy. Finally, we point out global trends in research into modern technologies used in the field of molecular microbiology to develop new vaccines. We focus on the vaccines designed to fight the infections caused by S. aureus, which are often resistant to the majority of available therapeutic options.

Active Surveillance, Drug Resistance, and Genotypic Profiling of Staphylococcus aureus Among School-Age Children in China

Methicillin-susceptible (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization predisposes individuals for endogenous infections and is a major threat to children. Recently, oxacillin/cefoxitin-susceptible mecA-positive S. aureus (OS-MRSA) has been reported worldwide. Herein, a prospective, cross-sectional study was conducted across five schools, representing three educational stages, in Guangzhou, China. Nasal swabs from 2,375 students were cultured for S. aureus and all isolates were subjected to antibiotic susceptibility testing phenotypically and confirmed by femB and mecA genetic detection; all the isolates were classified as MSSA, MRSA, or OS-MRSA. All strains were also analyzed by multi-locus sequence typing. Among the 2,375 swabs, S. aureus was detected in 744 children (31.3%, 95% CI: 25.9–36.7%), of whom 72 had MRSA (3.0%, 95% CI: 0.6–5.4%) and 4 had OS-MRSA (0.2%, 95% CI: 0.1–0.3%), of which an oxacillin- and cefoxitin-susceptible MRSA strain was identified. The prevalence of S. aureus and MRSA was higher in younger children. The highest percentage of drug resistance of the S. aureus isolates (n = 744) was to penicillin (85.5%), followed by erythromycin (43.3%) and clidamycin (41.0%). The most prevalent sequence types (STs) were ST30, ST45, and ST188 in MSSA, accounting for 38.7% of the total isolates, whereas ST45, ST59, and ST338 accounted for 74.6% of the MRSA isolates and ST338 accounted for 50.0% of the OS-MRSA isolates. The MRSA and OS-MRSA isolates (n = 76) were grouped into three clades and one singleton, with clonal complex (CC) 45 as the most predominant linkage. The top nine multi-locus sequence typing-based CCs (CC30, CC45, CC5, CC1, CC15, CC944, CC398, CC59, CC7) represented 86.7% of all S. aureus isolates. All CC30 isolates were resistant to erythromycin and clidamycin, and almost all these isolates were also resistant to penicillin (99.2%). The CC45 and CC59 isolates exhibited high resistance rates to oxacillin at 31.5 and 59.0%, respectively. This study provides updated data valuable for designing effective control strategies to mitigate the burden of disease and to improve the adequacy of empirical antimicrobial treatments for potentially harmful infections.

Prevalence of methicillin-resistant Staphylococcus aureus in Iranian children: a systematic review and meta-analysis

BACKGROUND

Antibiotic resistance is associated with longer hospitalizations, higher treatment costs, and increased morbidity and mortality rates.

PURPOSE

This study aimed to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in Iranian children.

METHODS

International databases, including Web of Science, PubMed, Embase, and Scopus, and Iranian databases, including Scientific Information Database (www.sid.ir), Magiran, and Iranian Database for Medical Literature (idml.research.ac.ir), were systematically searched for articles published between January 2000 and August 2019. Sources of heterogeneity were determined using subgroup analysis and meta-regression.

RESULTS

Overall, 343 studies were identified; of them, 20 were included in the meta-analysis to estimate the pooled prevalence. The pooled prevalence of MRSA was 42% (95% confidence interval [CI], 29-55) among culture-positive cases of S. aureus, 51% (95% CI, 39-62) in hospitalized children, and 14% (95% CI, 0.05-27) in healthy children.

CONCLUSION

The overall pooled prevalence of MRSA in children was 42%. Appropriate infection control measures and effective antibiotic therapy are needed.

Nasal Methicillin-Resistant Staphylococcus aureus Colonization in Patients with Type 1 Diabetes in Taiwan

Nasal methicillin-resistant Staphylococcus aureus (MRSA) colonies are an essential reservoir of infection, especially for patients with diabetes. However, data on MRSA colonization in patients with type 1 diabetes are limited. We investigated the epidemiology of MRSA colonization in patients with type 1 diabetes. This prospective cross-sectional study was conducted in a medical center (Chang Gung Memorial Hospital) in Taiwan from 1 July to 31 December 2020. Nasal sampling and MRSA detection were performed. The molecular characteristics of MRSA isolates were tested, and factors associated with MRSA colonization were analyzed. We included 245 patients with type 1 diabetes; nasal MRSA colonization was identified in 13 (5.3%) patients. All isolates belonged to community-associated MRSA genetic strains; the most frequent strain was clonal complex 45 (53.8%), followed by ST59 (30.8%) (a local community strain). MRSA colonization was positively associated with age ≤ 10 years, body mass index < 18 kg/m², and diabetes duration < 10 years; moreover, it was negatively associated with serum low-density lipoprotein cholesterol ≥ 100 mg/dL. No independent factor was reported. The nasal MRSA colonization rate in type 1 diabetes is approximately 5% in Taiwan. Most of these colonizing strains are community strains, namely clonal complex 45 and ST59.

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

Objective

To assess the prevalence and risk factors for S. aureus and methicillin-resistant S. aureus (MRSA) nasal colonization in Spanish children.

Methods

Cross-sectional study of patients <14 years from primary care centers all over Spain. Clinical data and nasal aspirates were collected from March to July 2018.

Results

A total of 1876 patients were enrolled. Prevalence of S. aureus and MRSA colonization were 33% (95% CI 30.9–35.1) and 1.44% (95% CI 0.9–2), respectively. Thirty-three percent of the children (633/1876) presented chronic conditions, mainly atopic dermatitis, asthma and/or allergy (524/633). Factors associated with S. aureus colonization were age ≥5 years (OR 1.10, 95% CI 1.07–1.12), male sex (OR 1.43, 95% CI 1.17–1.76), urban setting (OR 1.46, 95% CI 1.08–1.97) and the presence of asthma, atopic dermatitis or allergies (OR 1.25; 95% CI: 1.093–1.43). Rural residence was the only factor associated with MRSA colonization (OR 3.62, 95% CI 1.57–8.36). MRSA was more frequently resistant than methicillin-susceptible S. aureus to ciprofloxacin [41.2% vs 2.6%; p<0.0001], clindamycin [26% vs 16.9%; p=0.39], and mupirocin [14.3% vs 6.7%; p=0.18]. None of the MRSA strains was resistant to tetracycline, fosfomycin, vancomycin or daptomycin.

Conclusions

The main risk factors for S. aureus colonization in Spanish children are being above five years of age, male gender, atopic dermatitis, asthma or allergy, and residence in urban areas. MRSA colonization is low, but higher than in other European countries and is associated with rural settings.

Molecular characteristics and antimicrobial susceptibility of Staphylococcus aureus among children with respiratory tract infections in southwest China

BACKGROUND

The molecular characteristics and antimicrobial susceptibility of Staphylococcus aureus (S. aureus) in general pediatric wards and county-level hospitals were rarely reported in China.

METHODS

Staphylococcus aureus was isolated from children hospitalized with respiratory tract infection (RTI) in Zhongjiang and Youyang counties in 2015. All isolates were typed by multilocus sequence, staphylococcal protein A, accessory gene regulator (agr), and staphylococcal cassette chromosome mec [SCCmec, for methicillin-resistant S. aureus (MRSA) only]. Polymerase chain reaction was used to screen 21 super-antigen (SAg) genes and panton-valentine leukocidin (pvl). Antimicrobial susceptibility testing was performed by E test.

RESULTS

A total of 2136 children were enrolled. Overall, 125 (5.9%) children carried S. aureus, among which MRSA accounted for 42.4%. ST59-SCCmec type IV-t437-agr group I (58.5%) was the most prevalent genotype in MRSA, and ST188-t189-agr group I (22.2%) was the top genotype in methicillin-sensitive S. aureus (MSSA). The pvl carriage rate in MRSA and MSSA was 15.1% and 9.7%, respectively (P = 0.4112). About 96.8% of S. aureus isolates were positive for at least one SAg gene. The most common SAg gene profile in the dominant ST59 clone was seb-sek-seq (42.8%). All S. aureus isolates were resistant to penicillin and erythromycin (minimum inhibitory concentration 90 was > 32 and 256 mg/L to penicillin and erythromycin, respectively), but usually susceptible to other tested non-β-lactam antimicrobials.

CONCLUSIONS

Staphylococcus aureus and MRSA were detected with a high frequency in children with RTI in county-level hospitals of China. ST59-SCCmec type IV-t437-agr group I was the dominant MRSA clone. The S. aureus isolates exhibited high resistance to penicillin and erythromycin.

Prevalence, Characterization, and Drug Resistance of Staphylococcus Aureus in Feces From Pediatric Patients in Guangzhou, China

Background: Staphylococcus aureus (S. aureus) is a major pathogen of human infections. Its fecal carriage serves as a risk factor for nosocomial transmission and disease development. However, the rate of S. aureus fecal carriage among Chinese children has not yet been reported. Therefore, we sought to investigate the prevalence, characterization, and drug resistance of S. aureus isolated from pediatric patients' feces in Southern China. Methods: Fecal samples (2059) from pediatric patients in three centers in Guangzhou were cultured. From which, 412 S. aureus isolates were identified via selective mediums and automated VITEK Mass Spectrometer analysis. Antibiotic susceptibility was determined and DNA sequencing of seven housekeeping genes were used for multilocus sequence typing analysis. Results: The fecal carriage rates were 20.0% for S. aureus and 4.5% for methicillin-resistant S. aureus (MRSA). Moreover, S. aureus fecal carriage was positively correlated with outpatient status and gastroenteritis diagnosis. Moreover, age-related patterns were observed with respect to prevalence of S. aureus. Besides, a total of 76 sequence types (STs) were identified, including 25 newly assigned STs and 28 clonal complexes (CCs). ST188, ST6, and ST15 were the most prevalent methicillin-sensitive S. aureus (MSSA) clones, while ST59 and ST45 were the major MRSA clones. S. aureus isolates also exhibited high rates of penicillin (84.2%), erythromycin (38.8%), and clindamycin (35.9%) resistance. Specifically, all ST30 and ST338 isolates were resistant to erythromycin and clindamycin, 61% of ST7 were resistant to tetracycline, and 84% of ST45 exhibited resistance and intermediate resistance to rifampicin. Also, CC59 (ST338 and ST59) and CC45 exhibited different antibiotic resistance patterns. Conclusion: These results demonstrate the colonization dynamics and molecular epidemiology of S. aureus in child feces in Southern China. Further, they suggest an urgency for strengthening the surveillance programs in China and provide important information for the prevention and treatment of S. aureus infection.

Antibiotic Prophylaxis for Open Chest Management After Pediatric Cardiac Surgery

OBJECTIVES

Although open chest management optimizes hemodynamics after cardiac surgery, it increases postoperative infections and leads to increased mortality. Despite the importance of antibiotic prophylaxis during open chest management, no specific recommendations exist. We aimed to compare the occurrence rates of bloodstream infection and surgical site infection between the different prophylactic antibiotic regimens for open chest management after pediatric cardiac surgery.

DESIGN

Retrospective, single-center, observational study.

SETTING

PICU at a tertiary children's hospital.

PATIENTS

Consecutive patients younger than or equal to 18 years old with open chest management after cardiac surgery followed by delayed sternal closure, between January 2012 and June 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We compared the composite occurrence rate of postoperative bloodstream infection and surgical site infection within 30 days after cardiac surgery between three prophylactic antibiotic regimens: 1) cefazolin, 2) cefazolin + vancomycin, and 3) vancomycin + meropenem. In 63 pediatric cardiac surgeries with open chest management, 17 bloodstream infections, and 12 surgical site infections were identified postoperatively. The composite occurrence rates of bloodstream infection and surgical site infection were 10 of 15 (67%), 10 of 19 (53%), and nine of 29 (31%) in the cefazolin, cefazolin + vancomycin, and vancomycin + meropenem regimens, respectively (p = 0.07). After adjusting for age, open chest management duration, extracorporeal membrane oxygenation use, and nasal methicillin-resistant Staphylococcus aureus colonization in multivariable analysis, there was no significant difference between the cefazolin and the cefazolin + vancomycin regimens (p = 0.19), while the vancomycin + meropenem regimen had a lower occurrence rate of bloodstream infection and surgical site infection than the cefazolin regimen (odds ratio, 0.0885; 95% CI, 0.0176-0.446; p = 0.003).

CONCLUSIONS

In this study, a lower occurrence rate of postoperative bloodstream infection and surgical site infection was observed among patients with broad-spectrum antibiotic regimen after pediatric cardiac surgery with open chest management. Further studies, ideally randomized controlled studies investigating the efficacy of broad-spectrum antibiotics and their complications, are warranted before routine implementation of broad-spectrum prophylactic antibiotic regimen.

The prevalence of methicillin-resistant Staphylococcus aureus among diabetic patients: a meta-analysis

AIMS

Diabetic patients have multiple risk factors for colonisation with methicillin-resistant Staphylococcus aureus (MRSA), a nosocomial pathogen associated with significant morbidity and mortality. This meta-analysis was conducted to estimate the prevalence of MRSA among diabetic patients.

METHODS

The MEDLINE, Embase, BIOSIS, and Web of Science databases were searched for studies published up to May 2018 that reported primary data on the prevalence of MRSA in 10 or more diabetic patients. Two authors independently assessed study eligibility and extracted the data. The main outcomes were the pooled prevalence rates of MRSA colonisation and infection among diabetic populations.

RESULTS

Eligible data sets were divided into three groups containing data about the prevalence of MRSA colonisation or in diabetic foot or other infections. From 23 data sets, the prevalence of MRSA colonisation among 11577 diabetics was 9.20% (95% CI, 6.26-12.63%). Comparison of data from 14 studies that examined diabetic and non-diabetic patients found that diabetics had a 4.75% greater colonisation rate (P < 0.0001). From 41 data sets, the prevalence of MRSA in 10994 diabetic foot infection patients was 16.78% (95% CI, 13.21-20.68%). Among 2147 non-foot skin and soft-tissue infections, the MRSA prevalence rate was 18.03% (95% CI, 6.64-33.41).

CONCLUSIONS

The prevalence of MRSA colonisation among diabetic patients is often higher than among non-diabetics; this may make targeted screening attractive. In the UK, many diabetic patients may already be covered by the current screening policies. The prevalence and impact of MRSA among diabetic healthcare workers requires further research. The high prevalence of MRSA among diabetic foot infections may have implications for antimicrobial resistance, and should encourage strategies aimed at infection prevention or alternative therapies.

Prevalence of Cefepime-Resistant Escherichia coli in Iran: A Meta-Analysis (2007-2016)

BACKGROUND

Cefepime-resistant Escherichia coli (E. coli) is one of the seven important types of microbial resistance. This meta-analysis study was conducted to identify the prevalence of cefepime-resistant E. coli in Iran during 2007-2016.

METHODS

Studies published were searched in Persian databases (including Magiran, and SID) and international databases (including PubMed, ScienceDirect, and Scopus). The selected studies included all types of laboratory methods. Moreover, the random effects model (DerSimonian Laird method) was used to addresses the high heterogeneity (50% < I²) between the reviewed studies. The collected data were categorized into different subgroups on the basis of the year of study and province. Data analysis was performed using the Statsdirect software.

RESULTS

Overall, 516 articles were selected from the searched medical databases. After reviewing and applying the inclusion criteria, irrelevant papers were excluded and the remaining 26 studies were meta-analyzed. The overall prevalence of cefepime-resistant E. coli was 53.42% (95%: 43.35, 63.35), ranging from 25% (95%CI: 21.67, 28.55) in 2009 to 61.95% (95%CI: 56.62, 67.09) in 2016.

CONCLUSION

The prevalence of cefepime-resistant E. coli in Iran has had an increasing and alarming trend during the recent years. Therefore, it is necessary to use practical strategies and interventions to control and monitor cefepime-resistant E. coli in the country.

Prevalence and Genetic Characteristics of Methicillin-Resistant Staphylococcus aureus and Coagulase-Negative Staphylococci Isolated from Oral Cavity of Healthy Children in Japan

Prevalence and genetic characteristics of methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci in oral cavity of healthy children were studied in Hokkaido, northern main island of Japan. From saliva of 526 children, a total of 248 staphylococcal isolates comprising S. aureus (n = 143), S. epidermidis (n = 84), S. warneri (n = 13), S. haemolyticus (n = 5), S. hominis (n = 2), and S. intermedius (n = 1) were recovered. Presence of mecA was confirmed in 6.3% of S. aureus, 50% of S. epidermidis, and 7.7% in S. warneri. SCCmec was mostly classified into type IV, and ACME (arginine catabolic mobile element)-arcA was detected in S. epidermidis (23.8%) and S. intermedius. Nine MRSA isolates belonged to staphylocoagulase gene (coa) type Ia, IIa, IIIa, VIIb/sequence type 1 (ST1), ST5, ST8, ST89, ST120, and were negative for PVL (Panton-Valentine leukocidin) genes. These isolates included two clones of emerging community-acquired MRSA (CA-MRSA) that had been described recently in Japan: ST5/SCCmec IVc, which resembles the "Pediatric clone," and ST8/SCCmec IVl belonging to coa-IIIa/agr-I with sasL gene, designated "CA-MRSA/J" clone. Various enterotoxin genes were found in all the MRSA and some methicillin-susceptible S. aureus (MSSA) isolates examined, while tst-1 was detected in four MRSA isolates. Notably, a variant of elastin-binding protein gene (ebpS-v) was identified in ST120 MRSA and ST45 MSSA isolates, and exfoliative toxin D gene (etd) was detected in an MSSA isolate. The present study revealed the presence of MRSA, including the novel CA-MRSA clones, and high prevalence of methicillin-resistant S. epidermidis in oral cavity of healthy children in Japan.