Differences in gram-positive bacterial colonization and antimicrobial resistance among children in a high income inequality setting

Longitudinal monitoring of sewershed resistomes in socioeconomically diverse urban neighborhoods

BACKGROUND

Understanding factors associated with antimicrobial resistance (AMR) distribution across populations is a necessary step in planning mitigation measures. While associations between AMR and socioeconomic-status (SES), including employment and education have been increasingly recognized in low- and middle-income settings, connections are less clear in high-income countries where SES remains an important influence on other health outcomes.

METHODS

We explored the relationship between SES and AMR in Calgary, Canada using spatially-resolved wastewater-based surveillance of resistomes detected by metagenomics across eight socio-economically diverse urban neighborhoods. Resistomes were established by shotgun-sequencing of wastewater pellets, and qPCR of targeted-AMR genes. SES status was established using 2021 Canadian census data. Conducting this comparison during the height of COVID-related international travel restrictions (Dec. 2020-Oct. 2021) allowed the hypotheses linking SES and AMR to be assessed with limited confounding. These were compared with sewage metagenomes from 244 cities around the world, linked with Human Development Index (HDI).

RESULTS

Wastewater metagenomes from Calgary's socioeconomically diverse neighborhoods exhibit highly similar resistomes, with no quantitative differences (p > 0.05), low Bray-Curtis dissimilarity, and no significant correlations with SES. By comparison, dissimilarity is observed between globally-sourced resistomes (p < 0.05), underscoring the homogeneity of resistomes in Calgary's sub-populations. The analysis of globally-sourced resistomes alongside Calgary's resistome further reveals lower AMR burden in Calgary relative to other cities around the world. This is particularly pronounced for the most clinically-relevant AMR genes (e.g., beta-lactamases, macrolide-lincosamide-streptogramin).

CONCLUSIONS

This work showcases the effectiveness of inclusive and comprehensive wastewater-based surveillance for exploring the interplay between SES and AMR.

Long-term outcomes of patients with toxic shock syndrome: A matched cohort study

OBJECTIVES

We examined long-term outcomes of toxic shock syndrome.

METHODS

We conducted a matched cohort study of 630 patients with toxic shock syndrome and 5009 healthy controls between 2006 and 2021 in Quebec, Canada. Outcomes included hospitalization for renal, cardiovascular, hepatic, and other morbidity during 15 years of follow-up. We estimated adjusted hazard ratios (HR) and 95% confidence intervals (CI) for the risk of these outcomes over time, comparing patients with toxic shock syndrome relative to matched controls.

RESULTS

Compared with healthy controls, rehospitalization rates at 15 years were higher for men with toxic shock syndrome (52.0 vs 30.0 per 100) but not for women (38.7 vs 45.6 per 100). In men, toxic shock syndrome was associated with an elevated risk of renal (HR 17.43, 95% CI 6.35-47.82), cardiovascular (HR 2.57; 95% CI 1.52-4.34), and hepatic hospitalization (HR 19.83, 95% CI 4.72-83.34). In women, toxic shock syndrome was associated with renal hospitalization (HR 4.71, 95% CI 1.94-11.45). Streptococcal toxic shock was associated with a greater risk of rehospitalization than staphylococcal toxic shock.

CONCLUSIONS

Toxic shock syndrome is associated with rehospitalization up to 15 years later, especially in men. These patients may benefit from continued follow-up to prevent long-term morbidity.

Is neighborhood deprivation index a risk factor for Staphylococcus aureus infections?

BACKGROUND

We assessed the association between neighborhood area deprivation index (ADI) and community-onset (co) and hospital-onset (ho) Staphylococcus aureus infection.

METHODS

Demographic and clinical characteristics of patients admitted to 5 adult hospitals in the mid-Atlantic between 2016 and 2018 were obtained. The association of ADI with methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) S aureus infections was assessed using logistic regression models adjusting for severity of illness and days of admission.

RESULTS

Overall, increasing ADI was associated with higher odds of co- and ho-MRSA and MSSA infection. In univariate analysis, Black race was associated with 44% greater odds of ho-MRSA infection (odds ratio [OR] 1.44; 95% CI 1.18-1.76) and Asian race (co-MRSA OR 0.355; Confidence Interval (CI) 0.240-0.525; co-MSSA OR 0.718; CI 0.557-0.928) and unknown race (co-MRSA OR 0.470; CI 0.365-0.606; co-MSSA OR 0.699; CI 0.577-0.848) was associated with lower odds of co-MSSA and co-MRSA infections. When both race and ADI were included in the model, Black race was no longer associated with ho-MRSA infections whereas Asian and unknown race remained associated with lower odds of co-MRSA and co-MSSA infection. In the multivariable logistic regression, ADI was consistently associated with increased odds of S aureus infection (co-MRSA OR 1.132; CI 1.064-1.205; co-MSSA OR 1.089; CI 1.030-1.15; ho-MRSA OR 1.29; CI 1.16-1.43: ho-MSSA OR 1.215; CI 1.096-1.346).

CONCLUSIONS

The area deprivation index is associated with community and hospital-onset MRSA and MSSA infections.

Systemic infection caused by the methicillin-resistant Staphylococcus aureus USA300-LV lineage in a Brazilian child previously colonized

The methicillin-resistant Staphylococcus aureus (MRSA) USA300-Latin American variant (USA300-LV) lineage is well documented in northern Latin American countries. It has replaced established clones in hospital environments. We herein report a systemic infection caused by a USA300-LV isolate in a 15-year-old boy, from a low-income area of Rio de Janeiro, previously colonized by the same strain. During hospital stay, seven pvl-positive MRSA USA300-LV isolates were recovered by nasal swab, blood and abscess secretion. The patient underwent intravenous vancomycin, daptomycin, and oral sulfamethoxazole/trimethoprim, and was discharged after 45 days after full recovery. This is the first documented case of a community-acquired MRSA infection caused by the USA300-LV variant in Brazil in a previously colonized adolescent with no history of recent travel outside of Rio de Janeiro. The need for improved surveillance programs to detect MRSA colonization in order to control the spread of hypervirulent lineages among community and hospital settings is highlighted.

Methicillin-resistant and methicillin-sensitive Staphylococcus aureus isolates from skin and nares of Brazilian children with atopic dermatitis demonstrate high level of clonal diversity

BACKGROUND

Atopic dermatitis (AD) primarily affects the pediatric population, which is highly colonized by S. aureus. However, little is known about the genetic features of this microorganism and other staphylococcal species that colonize AD patients.

OBJECTIVE

This study aimed to characterize Staphylococcus spp. isolated from the nares and skin (with and without lesion) of 30 AD and 12 non-AD Brazilian children.

METHODS

Skin and nasal swabs were cultured onto mannitol salt agar, and bacterial colonies were counted and identified by matrix assisted laser desorption ionization time of flight mass spectrometry and polymerase chain reaction (PCR). Antimicrobial susceptibility was evaluated by phenotypic and genotypic tests. In S. aureus isolates, Panton-Valentine leukocidin genes were detected by PCR, and their clonality was assessed by pulsed-field gel electrophoresis and multilocus sequence typing.

RESULTS

S. aureus was more prevalent in the nares (P = 0.005) and lesional skin (P = 0.0002) of children with AD, while S. hominis was more frequent in the skin of non-AD children (P < 0.0001). All children in the study, except one from each group, were colonized by methicillin-resistant coagulase-negative Staphylococcus and 24% by methicillin-resistant S. aureus. Despite the great clonal diversity of S. aureus (18 sequence types identified), most AD children (74.1%) were colonized by the same genotype in both niches.

CONCLUSION

High colonization by polyclonal S. aureus isolates was found among children with AD, while S. hominis was more frequent among non-AD children. The high prevalence of methicillin-resistant staphylococcal isolates highlights the importance of continued surveillance, especially when considering empiric antibiotic therapy for the treatment of skin infections in these patients.

Influence of Socioeconomic and Environmental Determinants of Health on Human Infection and Colonization with Antibiotic-Resistant and Antibiotic-Associated Pathogens: A Scoping Review

Background: Antibiotic-resistant and antibiotic-associated pathogens are commonly encountered by surgeons. Pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), Clostridioides difficile infection (CDI), and carbapenem-resistant Enterobacteriaceae (CRE) result in considerable human morbidity, mortality, and excess healthcare expenditure. Human colonization or infection can result from exposure to these pathogens across a range of domains both inside and outside of the built healthcare environment, exposure that may be influenced by socioeconomic and environmental determinants of health, the importance of which has not been investigated fully. Methods: We performed a scoping review of published literature describing potential socioeconomic and environmental variables that may increase the likelihood of human infection or colonization with common antibiotic-resistant or antibiotic-associated pathogens, using MRSA, CDI, and CRE as examples. Results: We identified 7,916 articles meeting initial search criteria. Of these, 101 provided supportive evidence of socioeconomic and environmental determinants of human infection or colonization and were included in the scoping review after abstract and full-text screening. Sixty-seven evaluated MRSA, nine evaluated CRE, and 29 evaluated CDI. Twenty-nine articles evaluated exposure to livestock or companion animals; 28, exposure to antibiotics; 20, impact of socioeconomic factors, education level, or race; 14, the influence of temperature, humidity, or season; 13, the effect of travel or human population migration; 11, exposure to built healthcare environments; and eight assessed impact of population density or urbanization. Conclusions: Although articles outlining socioeconomic and environmental drivers of antibiotic-resistant and antibiotic-associated infection are still disconcertedly few, evidence of such associations are overwhelming for MRSA and CDI and supportive for CRE. Additional research is needed to investigate the role and importance of different potential socioeconomic and environmental drivers of antibiotic-resistant and antibiotic-associated infections and colonization in humans.

Risk Factors for Recurrent Staphylococcus aureus Bacteremia

BACKGROUND

To understand the clinical, bacterial, and host characteristics associated with recurrent Staphylococcus aureus bacteremia (R-SAB), patients with R-SAB were compared to contemporaneous patients with a single episode of SAB (S-SAB).

METHODS

All SAB isolates underwent spa genotyping. All isolates from R-SAB patients underwent pulsed-field gel electrophoresis (PFGE). PFGE-indistinguishable pairs from 40 patients underwent whole genome sequencing (WGS). Acute phase plasma from R-SAB and S-SAB patients was matched 1:1 for age, race, sex, and bacterial genotype, and underwent cytokine quantification using 25-analyte multiplex bead array.

RESULTS

R-SAB occurred in 69 (9.1%) of the 756 study patients. Of the 69 patients, 30 experienced relapse (43.5%) and 39 reinfection (56.5%). Age, race, hemodialysis dependence, presence of foreign body, methicillin-resistant Staphyloccus aureus, and persistent bacteremia were individually associated with likelihood of recurrence. Multivariate risk modeling revealed that black hemodialysis patients were nearly 2 times more likely (odds ratio [OR] = 9.652 [95% confidence interval [CI], 5.402-17.418]) than white hemodialysis patients (OR = 4.53 [95% CI, 1.696-10.879]) to experience R-SAB. WGS confirmed PFGE interpretations in all cases. Median RANTES (regulated on activation, normal T cell expressed and secreted) levels in acute phase plasma from the initial episode of SAB were higher in R-SAB than in matched S-SAB controls (P = .0053, false discovery rate < 0.10).

CONCLUSION

This study identified several risk factors for R-SAB. The largest risk for R-SAB is among black hemodialysis patients. Higher RANTES levels in R-SAB compared to matched controls warrants further study.

Prevalence of group B streptococcal colonization in the healthy non-pregnant population: a systematic review and meta-analysis

BACKGROUND

Colonization and transmission precede invasive group B streptococcal (GBS) disease. Data on GBS colonization prevalence, detection methods and risk factors for carriage are relevant for vaccine development and to understand GBS pathogenesis.

OBJECTIVES

To evaluate GBS colonization prevalence after the first week of life in the healthy non-pregnant population.

DATA SOURCES

Pubmed/Medline, Embase, Latin American and Caribbean Health Sciences Literature, World Health Organization Library Information System, and Scopus. Search performed 12 January 2021 with search terms related to 'GBS' and 'colonization, epidemiology, prevalence or screening' without restrictions.

STUDY ELIGIBILITY CRITERIA

All studies that reported prevalence of GBS colonization (any site) in the healthy population.

PARTICIPANTS

All individuals (>6 days of age), with no indication of pregnancy, invasive disease or severe underlying immunological co-morbidities.

METHODS

Logit transformation and a random effects model (DerSimonian and Laird) were used to pool colonization estimates. Subgroup analysis and meta-regression on a priori determined subgroups were performed.

RESULTS

We included 98 studies with 43 112 participants. Our search identified 9309 studies of which 8831 were excluded based on title and abstract and 380 after reading the full text. Colonization rates varied considerably between studies (I² = 97%), which could be partly explained by differences in culture methods (R² = 27%), culture sites (R² = 24%), continent (R² = 10%) and participant's age (R² = 6%). Higher prevalence was found with selective culture methods (19%, 95% CI 16%-23% versus non-selective methods 8%, 95% CI 6%-9%; p < 0.0001). Colonization rates were highest in rectum (19%, 95% CI 15%-24%), vagina (14%, 95% CI 12%-17%) and urethra (9%, 95% CI 5%-18%). In participants with negative rectal cultures, 7% (95% CI 5%-9%) had GBS cultured from another niche. Colonization prevalence was lower in children (6 months to 16 years; 3%, 95% CI 2%-5%) compared with adults (16%, 95% CI 14%-20%; p < 0.0001). Using selective culture methods in adults resulted in a prevalence of 26% (95% CI 19%-33%) rectal, 21% (95% CI 17%-25%) vaginal and 9% (95% CI 6%-14%) urethral colonization.

CONCLUSION

The rectum is the most common body site colonized by GBS. The best approach to screen for any GBS colonization is to screen multiple body sites using selective culture methods.

Virulence Factors Found in Nasal Colonization and Infection of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates and Their Ability to Form a Biofilm

Hospitalizations related to Methicillin-resistant Staphylococcus aureus (MRSA) are frequent, increasing mortality and health costs. In this way, this study aimed to compare the genotypic and phenotypic characteristics of MRSA isolates that colonize and infect patients seen at two hospitals in the city of Niterói—Rio de Janeiro, Brazil. A total of 147 samples collected between March 2013 and December 2015 were phenotyped and genotyped to identify the protein A (SPA) gene, the mec staphylococcal chromosomal cassette (SCCmec), mecA, Panton-Valentine Leucocidin (PVL), icaC, icaR, ACME, and hla virulence genes. The strength of biofilm formation has also been exploited. The prevalence of SCCmec type IV (77.1%) was observed in the colonization group; however, in the invasive infection group, SCCmec type II was prevalent (62.9%). The Multilocus Sequence Typing (MLST), ST5/ST30, and ST5/ST239 analyses were the most frequent clones in colonization, and invasive infection isolates, respectively. Among the isolates selected to assess the ability to form a biofilm, 51.06% were classified as strong biofilm builders. Surprisingly, we observed that isolates other than the Brazilian Epidemic Clone (BEC) have appeared in Brazilian hospitals. The virulence profile has changed among these isolates since the ACME type I and II genes were also identified in this collection.

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.

The History of Methicillin-Resistant Staphylococcus aureus in Brazil

Since the emergence of MRSA in the 1960s, a gradual increase in infections by resistant bacteria has been observed. Clinical manifestations may vary from brand to critical condition due to host risk factors, as well as pathogen virulence and resistance. The high adaptability and pathogenic profile of MRSA clones contributed to its spread in hospital and community settings. In Brazil, the first MRSA isolates were reported in the late 1980s, and since then different genetic profiles, such as the Brazilian epidemic clone (BEC) and other clones considered a pandemic, became endemic in the Brazilian population. Additionally, Brazil's MRSA clones were shown to be able to transfer genes involved in multidrug resistance and enhanced pathogenic properties. These events contributed to the rise of highly resistant and pathogenic MRSA. In this review, we present the main events which compose the history of MRSA in Brazil, including numbers and locations of isolation, as well as types of staphylococcal cassette chromosome mec (SCCmec) found in the Brazilian territory.

Educational Attainment and Staphylococcus aureus Colonization in a Hispanic Border Community: Testing Fundamental Cause Theory

Unlike some types of S. aureus infections, S. aureus colonization is not associated with ethnicity or educational attainment and thus may be outside the influence of socioeconomic status-based resources typically mobilized to avoid or mitigate preventable health risks. This assessment of a clinically silent risk that usually precedes infections may illustrate a boundary of fundamental cause theory.

This study was carried out to evaluate hypotheses generated by fundamental cause theory regarding the socioeconomic status (SES) gradient in colonization with Staphylococcus aureus among Hispanic and non-Hispanic adults living in a border community. Participants (n = 613) recruited in naturally occurring small groups at public and private sites throughout Yuma County, AZ, completed a sociodemographic survey and swabbed their palms, noses, and throats to sample microbial flora. Positive S. aureus colonization among non-Hispanic white participants was nominally higher (39.0%; 95% confidence interval [CI] = 32.4 to 46.1%) than that in Hispanics (31.3%; 95% CI = 26.4 to 36.8%), but there was no education gradient for the sample overall (incidence rate ratio = 1.00; 95% CI = 0.90 to 1.12) or within each ethnic group separately. The education gradient between Hispanic and non-Hispanic whites was statistically equivalent. Results were consistent when home ownership was used as the SES indicator. These data show that S. aureus colonization is not linked to two different SES indicators or Hispanic ethnicity. S. aureus colonization may be considered a less preventable health risk that is outside the influence of SES-based resources.

IMPORTANCE Unlike some types of S. aureus infections, S. aureus colonization is not associated with ethnicity or educational attainment and thus may be outside the influence of socioeconomic status-based resources typically mobilized to avoid or mitigate preventable health risks. This assessment of a clinically silent risk that usually precedes infections may illustrate a boundary of fundamental cause theory.

Antibiotic Resistance And Genotyping Of Gram-Positive Bacteria Causing Hospital-Acquired Infection In Patients Referring To Children's Medical Center

Introduction

A serious problem affecting human society is the development of bacterial resistance. The purpose of the current study was to evaluate the antibiotic resistance of Gram-positive bacteria (GPB) and genotyping of common GPB causing hospital-acquired infections (HAIs) in patients who were referred to Children’s Medical Center during a 6-month period by random amplified polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus sequence polymerase chain reaction (ERIC-PCR).

Methods

During the 6-month period, antimicrobial resistance profiles of GPB isolates recovered from patients in Children’s Medical Center were determined using the Kirby–Bauer disk diffusion and MIC. Typing of common GPB was performed and the results were analyzed by gel compare software.

Results

In this cross-sectional study, 6524 cultures were performed and 138 Ggram-positive bacteria were isolated (2%). Staphylococcus aureus strains showed the highest antibiotic penicillin resistance (96.3%). Twenty-six per cent of the strains were methicillin-resistant S. aureus (MRSA) and no resistance was found against vancomycin. All isolates of Enterococcus faecium were resistant to ciprofloxacin (100%). The resistance to vancomycin was very high (67%) and no resistance was observed to linezolid. The results of genotyping analysis of S. epidermidis strains showed the presence of two clones with a genetic relationship of over 80%. All of the S. aureus strains were in one cluster and half of the E. faecium strains were in a cluster with a genetic predilection of over 80%.

Conclusion

This study indicated frequent occurrence of antimicrobial resistance, especially in Enterococcus spp. isolates. Rapid spreads of MRSA and VREF from a clonal origin require implementing careful isolation and infection control measures.