Determinants of methicillin-resistant Staphylococcus aureus (MRSA) prevalence in the Asia-Pacific region: A systematic review and meta-analysis

Epidemiological and microbiological characteristics of S. aureus pediatric infections in Colombia 2018-2021, a national multicenter study (Staphylored Colombia)

Background

Staphylococcus aureus infections are a significant cause of morbidity and mortality in pediatric populations worldwide. The Staphylo Research Network conducted an extensive study on pediatric patients across Colombia from 2018 to 2021. The aim of this study was to describe the epidemiological and microbiological characteristics of S. aureus in this patient group.

Methods

We analyzed S. aureus isolates from WHONET-reporting centers. An "event" was a positive culture isolation in a previously negative individual after 2 weeks. We studied center characteristics, age distribution, infection type, and antibiotic susceptibilities, comparing methicillin sensitive (MSSA) and resistant S. aureus (MRSA) isolates.

Results

Isolates from 20 centers across 7 Colombian cities were included. Most centers (80%) served both adults and children, with 55% offering oncology services and 85% having a PICU. We registered 8,157 S. aureus culture isolations from 5,384 events (3,345 MSSA and 1,961 MRSA) in 4,821 patients, with a median age of 5 years. Blood (26.2%) and skin/soft tissue (18.6%) were the most common infection sources. Most isolates per event remained susceptible to oxacillin (63.2%), clindamycin (94.3%), and TMP-SMX (98.3%). MRSA prevalence varied by city (<0.001), with slightly higher rates observed in exclusively pediatric hospitals. In contrast, the MRSA rate was somewhat lower in centers with Antimicrobial Stewardship Program (ASP). MRSA was predominantly isolated from osteoarticular infections and multiple foci, while MSSA was more frequently associated with recurrent infections compared to MRSA.

Conclusions

This is the largest study of pediatric S. aureus infections in Colombia. We found MSSA predominance, but resistance have important regional variations. S. aureus remains susceptible to other commonly used antibiotics such as TMP-SMX and clindamycin. Ongoing monitoring of S. aureus infections is vital for understanding their behavior in children. Prospective studies within the Staphylored LATAM are underway for a more comprehensive clinical and genetic characterization.

Nurses' satisfaction with an educational web application to prevent transmission of multidrug-resistant organisms

Multidrug-resistant organism infections are a serious health problem globally, and can result in patient mortality and morbidity. In this descriptive study, we produced the first web application for transmission prevention specific to the situation based on nursing experience, knowledge, and practice guidelines and to evaluate web application satisfaction among Thai nurses. The sample comprised 282 Thai registered nurses experienced in caring for patients with multidrug-resistant organisms in a tertiary hospital. A demographic form and knowledge test were completed anonymously online. Data were analyzed using descriptive statistics. The application emphasized crucial topics for which participants had low preliminary knowledge and included tutorial sessions, pictures, video clips, drills, and a post-test. The application was piloted with a random sample of 30 nurses, and an instrument tested their satisfaction with this. Results revealed that preliminary knowledge scores for preventing transmission were moderate, and participants were highly satisfied with the application. Findings suggest the application is suitable for Thai nurses and could be applied to nursing practice elsewhere. However, further testing is recommended before implementing it into nursing practice.

Comparative effectiveness and safety of six antibiotics in treating MRSA infections: A network meta-analysis

OBJECTIVES

This study conducted a network meta-analysis comparing linezolid, teicoplanin, daptomycin, tigecycline, and ceftaroline fosamil with vancomycin for treating MRSA-related diseases, addressing the lack of comprehensive evaluations in existing research on antibiotic therapy for MRSA infections.

METHODS

We systematically searched databases including PubMed, Embase, Web of Science, the Cochrane Librar up to August 22, 2023. All eligible randomized controlled trials of the six antibiotics were included in the NMA, and their effectiveness and safety were compared across various MRSA-related diseases. Categorical data were used for the odds ratio (OR), and continuous data were used for mean difference (SMD). The surface under the cumulative ranking (SUCRA) was employed to evaluate the incidence rate.

RESULTS

According to SUCRA results, daptomycin was the most effective treatment (73.0%) in bloodstream infections. In pulmonary infections and skin and soft tissue infections, linezolid out-performed other antibiotics in effectiveness rate (90.6% and 86.3%), microbial killing rate (93.3% and 93.1%). Vancomycin showed lower adverse reactions than teicoplanin, with less hepatotoxicity compared to linezolid and tigecycline. Linezolid had higher thrombocytopenia risk but lower nephrotoxicity risk than others. Vancomycin was less effective in microbial killing rates than linezolid across various infections.

CONCLUSION

The present research suggests that in pulmonary infections and skin and soft tissue infections, linezolid may be a better option for treating MRSA-related diseases. However, caution is warranted due to the association of linezolid with thrombocytopenia.

TRIAL REGISTRATION

Our study protocol was registered with the International Prospective Register of SystematicReviews (PROSPERO); Registration number: CRD42024535142.

Virtual screening and molecular dynamics simulation study of abyssomicins as potential inhibitors of COVID-19 virus main protease and spike protein

The lack of any effective cure for the infectious COVID-19 disease has created a sense of urgency and motivated the search for effective antiviral drugs. Abyssomicins are actinomyces-derived spirotetronates polyketides antibiotics known for their promising antibacterial, antitumor, and antiviral activities. In this study, computational approaches were used to investigate the binding mechanism and the inhibitory ability of 38 abyssomicins against the main protease (Mpro) and the spike protein receptor-binding domain (RBD) of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The results identified abyssomicins C, J, W, atrop-O-benzyl abyssomicin C, and atrop-O-benzyl desmethyl abyssomicin C as the most potential inhibitors of Mpro and RBD with binding energy ranges between -8.1 and -9.9 kcal mol-1; and between -6.9 and -8.2 kcal mol-1, respectively. Further analyses of physicochemical properties and drug-likeness suggested that all selected active abyssomicins, with the exception of abyssomicin J, obeyed Lipinski's rule of five. The stability of protein-ligand complexes was confirmed by performing molecular dynamics simulation for 100 ns and evaluating parameters such as such as root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration (Rg), solvent accessible surface area (SASA), total number of contacts, and secondary structure. Prime/MM-GBSA (Molecular Mechanics-General Born Surface Area) and principal component analysis (PCA) analyses also confirmed the stable nature of protein-ligand complexes. Overall, the results showed that the studied abyssomicins have significant interactions with the selected protein targets; therefore, they were deemed viable candidates for further in vitro and in vivo evaluation.Communicated by Ramaswamy H. Sarma.

BBD optimized antioxidants of Crotalaria candicans and its nanoconjugates, exert potent in vivo anti-biofilm effects against MRSA

Crotalaria genus is extensively dispersed in tropical and subtropical provinces, and it is found to harbor antioxidant flavonoids. Response surface methodology-based optimization was carried out for the purpose of efficient extraction involving a suitable solvent which can maximize the yield along with higher total phenolic content and total flavonoid content (TFC). Optimization conditions for extraction of C.candicans flavonoids (CCF) based on variables such as solvent, solid-solvent ratio and extraction temperature were evaluated. The optimized conditions were found as Solvent i.e., Aqueous-ethanol (53.42%), Solid-solvent ratio (1:15.83 w/v) and temperature (44.42 °C) and resulted to obtain the TFC as 176.23 mg QRET/g C. candicans extract with the yield 27.42 mg CCF/g (C. candicans dry weight). LC-MS analysis of CCF, revealed the presence of seven major flavonoids. The antioxidant flavonoids were further used to functionalize the zero-valent silver (ZVAgF) and copper (ZVCuF) nanoparticles. The ZVAgF and ZVCuF were investigated using UV-Vis spectrophotometry, FT-IR spectroscopy and X-ray diffractometry to confirm the presence of the zero valent metals and possible functional groups which capped the elemental metal. Further transmission electron microscopy, dynamic light scattering method and zeta-potential studies were done to understand their respective structural and morphological properties. The efficacy of the as-prepared ZVAgF/ZVCuF as antibiofilm agents on Methicillin-resistant Staphylococcus aureus (MRSA) with the mechanism studies have been explored. The MRSA-colony count from the infection zebrafish (in vivo) model, portrayed a reduction of > 1.9 fold for ZVCuF and > twofold for ZVAgF, with no alteration in liver morphology when treated with ZVAgF, implying that the nanoparticles were safe and biocompatible.

Screening for Methicillin-Resistant Staphylococcus aureus

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) has become less common in Germany in recent years. In this paper, we report data from the MRSA module of the Hospital Infection Surveillance System (Krankenhaus-Infektionen- Surveillance-System, KISS) for the years 2006-2021. We also describe the association of MRSA rates with the frequency of patient screening for MRSA and discuss the findings.

METHODS

Participation in the MRSA KISS module is voluntary. Once a year, the participating hospitals submit structural data, information on cases in which MRSA was detected (both colonizations and infections; both detected on admission and nosocomially acquired), and the number of nasal swabs taken for the detection of MRSA to the German National Reference Center for the Surveillance of Nosocomial Infections. Statistical analyses were performed with R software.

RESULTS

The number of hospitals participating in the MRSA module rose from 110 in 2006 to 525 in 2021. From 2006 onward, the overall MRSA prevalence in German hospitals increased, reaching a maximum of 1.04 cases per 100 patients in 2012. The prevalence on admission fell by 44% from 0.96 in 2016 to 0.54 in 2021. The incidence density of nosocomial MRSA fell by an average of 12% per year, from 0.27 per 1000 patient-days in 2006 to 0.06 in 2021, while MRSA screening frequency increased sevenfold by 2021. The nosocomial incidence density was stable, independently of the screening frequency.

CONCLUSION

MRSA rates in German hospitals fell markedly from 2006 to 2021, reflecting a general trend. The incidence density was no higher in hospitals with a low or moderate screening frequency than in those with a high one. Thus, a targeted, riskadapted MRSA screening strategy on hospital admission can be recommended.

Evaluation of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia: Epidemiology, clinical characteristics, and outcomes in the older patients in a tertiary teaching hospital in Malaysia

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is a major concern in the global healthcare system. However, data from Asian regions dealing with the singularity of this infection in older persons is lacking. We aimed to identify the differences in the clinical characteristics and outcomes of MRSA bacteremia between adults aged 18-64 and ≥ 65 years.

METHODS

A retrospective study cohort was conducted at the University Malaya Medical Centre (UMMC) on cases of MRSA bacteremia from 2012 to 2016. Patient demographic and clinical data were collected for risk factors analyses.

RESULTS

New cases of MRSA bacteremia showed a trend of increase from 0.12 to 100 admissions in 2012 to 0.17 per 100 admissions in 2016 but a drop was observed in 2014 (0.07 per 100 admissions). Out of the 275 patients with MRSA bacteremia, 139 (50.5%) patients were aged ≥ 65 years old. Co-morbidities and severity at presentation were significantly higher among older adults, including diabetes mellitus (p = 0.035), hypertension (p = 0.001), and ischemic heart disease (p < 0.001), as well as higher Charlson Comorbidity Index (p < 0.001) and Pitt bacteremia scores (p = 0.016). Central line-associated bloodstream infections were more common among younger patients (37.5% vs. 17.3% in older patients, p < 0.001), while skin and soft tissue infections are more frequent among older adults (20.9% vs. 10.3% in younger patients, p = 0.016). All-cause mortality and in-hospital mortality were significantly higher in older patients (82.7% and 56.1% vs. 63.2% and 28.7% in younger patients, p < 0.001). Multivariate analysis revealed age ≥ 65 years (adjusted odds ratio: 3.36; 95% confidence interval: 1.24-9.13), Pitt score ≥ 3 (2.15; 1.54-3.01), hospital (6.12; 1.81-20.72) and healthcare (3.19; 1.30-7.81) acquisition of MRSA, indwelling urinary catheters (5.43; 1.39-21.23), inappropriate targeted treatment (8.08; 1.15-56.86), lack of infectious disease team consultation (2.90; 1.04-8.11) and hypoalbuminemia (3.31; 1.25-8.79), were significant risk factors for 30-day mortality.

CONCLUSION

Older patients' risk of mortality from MRSA bacteremia was three times higher than younger patients. Our data will contribute to developing and validating a robust scoring system for risk-stratifying patients to achieve better management and improved clinical outcomes.

The Plasmidomic Landscape of Clinical Methicillin-Resistant Staphylococcus aureus Isolates from Malaysia

Methicillin-resistant Staphylococcus aureus (MRSA) is a priority nosocomial pathogen with plasmids playing a crucial role in its genetic adaptability, particularly in the acquisition and spread of antimicrobial resistance. In this study, the genome sequences of 79 MSRA clinical isolates from Terengganu, Malaysia, (obtained between 2016 and 2020) along with an additional 15 Malaysian MRSA genomes from GenBank were analyzed for their plasmid content. The majority (90%, 85/94) of the Malaysian MRSA isolates harbored 1-4 plasmids each. In total, 189 plasmid sequences were identified ranging in size from 2.3 kb to ca. 58 kb, spanning all seven distinctive plasmid replication initiator (replicase) types. Resistance genes (either to antimicrobials, heavy metals, and/or biocides) were found in 74% (140/189) of these plasmids. Small plasmids (<5 kb) were predominant (63.5%, 120/189) with a RepL replicase plasmid harboring the ermC gene that confers resistance to macrolides, lincosamides, and streptogramin B (MLS_B) identified in 63 MRSA isolates. A low carriage of conjugative plasmids was observed (n = 2), but the majority (64.5%, 122/189) of the non-conjugative plasmids have mobilizable potential. The results obtained enabled us to gain a rare view of the plasmidomic landscape of Malaysian MRSA isolates and reinforces their importance in the evolution of this pathogen.

Dissemination Pattern of Hospital-Acquired Methicillin-Resistant Staphylococcus aureus and Community-Acquired MRSA Isolates from Malaysian Hospitals: A Review from a Molecular Perspective

The global emergence of methicillin-resistant Staphylococcus aureus (MRSA) that unsusceptible to a wide selection of antimicrobial agents and any newly introduced antimicrobial over the past decades has triggered more extensive holistic measures to put an end to this situation. Molecular surveillance of MRSA clones is important to understand their evolutionary dynamics for investigating outbreaks, propagating precautionary measures, as well as planning for appropriate treatment. This review includes peer-reviewed reports on the molecular characterisation of clinical Staphylococcus aureus isolates within Malaysian hospitals from year 2008 to 2020. This work highlights the molecular clones of hospital-acquired MRSA (HA-MRSA) and community-acquired MRSA (CA-MRSA) isolates from Malaysian hospitals, with description on their ever-changing pattern. Among HA-MRSA, the ST22-t032-SCCmec IV MRSA clone was reported to supplant the previous dominating clone, ST239-t037-SCCmec III. Meanwhile, ST30, ST772, ST6 and ST22 were repeatedly detected in CA-MRSA, however, none of the strains became predominant. Future in-depth study on molecular epidemiology of MRSA clone is essential for the investigation of the extent of the clonal shift, especially in Malaysia.

Detection of Genes Encoding Microbial Surface Component Recognizing Adhesive Matrix Molecules in Methicillin-Resistant Staphylococcus aureus Isolated from Pyoderma Patients

Pyoderma is a common skin infection predominantly caused by Staphylococcus aureus. In addition to methicillin resistance, this pathogen is resistant to many other antibiotics, which ultimately limits the available treatment options. Therefore, the present study aimed to compare the antibiotic-resistance pattern, to detect the mecA gene and the genes encoding microbial surface component recognizing adhesive matrix molecules (MSCRAMMs) in S. aureus isolates. A total of 116 strains were isolated from patients suffering with pyoderma. Disk diffusion assay was opted to perform antimicrobial susceptibility testing of the isolates. Out of the isolates tested, 23-42.2% strains appeared susceptible to benzylpenicillin, cefoxitin, ciprofloxacin and erythromycin. While linezolid was found to be the most effective anti-staphylococcal drug, followed by rifampin, chloramphenicol, clindamycin, gentamicin and ceftaroline. Out of 116 isolates, 73 (62.93%) were methicillin-resistant S. aureus (MRSA). Statistically significant (p ≤ 0.05) differences in antibiotic resistance patterns between MRSA and methicillin-susceptible S. aureus (MSSA) were found. A significant association of resistance to ceftaroline, rifampin, tetracycline, ciprofloxacin, clindamycin, trimethoprim-sulfamethoxazole and chloramphenicol was found in MRSA. However, no significant difference was observed between MRSA and MSSA for resistance against gentamicin, erythromycin or linezolid. All cefoxitin-resistant S. aureus, nonetheless, were positive for the mecA gene. femA was found in all the MRSA isolates. Among other virulence markers, bbp and fnbB were found in all the isolates, while can (98.3%), clfA and fnbA (99.1%) were present predominately in MRSA. Thus, this study offers an understanding of antibiotic resistance MSCRAMMs, mecA, and femA gene patterns in locally isolated strains of S. aureus.

Antimicrobial resistance prevalence of Escherichia coli and Staphylococcus aureus amongst bacteremic patients in Africa: a systematic review

OBJECTIVES

Antimicrobial resistance (AMR) is a global concern among infectious diseases. Bloodstream infections can potentially become life-threatening if they become untreatable with conventional antimicrobials. This review aims to provide an understanding of the AMR prevalence and trends of common bacteremic pathogens, namely Escherichia coli and Staphylococcus aureus in the World Health Organization (WHO) Africa region.

METHODS

PubMed and Google Scholar were searched using relevant keywords for published human studies (excluding case reports and reviews) reporting bacteremic AMR data on the pathogens of interest between 2008 and 2019. Two reviewers independently screened the articles against a pre-defined eligibility criterion. Data extraction and analysis were achieved with different platforms: Covidence, Excel, R version 3.6.3, and QGIS v3.4.5. The pooled prevalence, 95% confidence intervals, and I² index (a measure of heterogeneity) were calculated for the various pathogen-antibiotic combinations.

RESULTS

Five hundred sixty-two papers were retrieved, with 27 papers included in the final analysis. Only 23.4% (11/47) of member states of the WHO African region had reports on AMR in bacteremia. The Clinical and Laboratory Standards Institute (CLSI) (78.5%) was the most common standard used in the region. For E. coli, the pooled resistance was: cefotaxime (42%), imipenem (4%), meropenem (0%), and colistin (0%). For S. aureus, the calculated pooled resistance was cloxacillin (34%), oxacillin (12%), and vancomycin (0%). There was a high degree of variation across studies (I² > 90%).

CONCLUSION

The pooled resistance rates indicate a concerning degree of methicillin-resistant and Extended Spectrum-ß-lactamase-producing pathogens. The paucity of AMR data also presents challenges for a comprehensive understanding of the situation in the region. Continent-wide and standardized surveillance efforts therefore need strengthening.

Diversity and Dissemination of Methicillin-Resistant Staphylococcus aureus (MRSA) Genotypes in Southeast Asia

Methicillin-resistant Staphylococcus aureus (MRSA) is a successful pathogen that has achieved global dissemination, with high prevalence rates in Southeast Asia. A huge diversity of clones has been reported in this region, with MRSA ST239 being the most successful lineage. Nonetheless, description of MRSA genotypes circulating in the Southeast Asia region has, until now, remained poorly compiled. In this review, we aim to provide a better understanding of the molecular epidemiology and distribution of MRSA clones in 11 Southeast Asian countries: Singapore, Malaysia, Thailand, Vietnam, Cambodia, Lao People's Democratic Republic (PDR), Myanmar, Philippines, Indonesia, Brunei Darussalam, and Timor-Leste. Notably, while archaic multidrug-resistant hospital-associated (HA) MRSAs, such as the ST239-III and ST241-III, were prominent in the region during earlier observations, these were then largely replaced by the more antibiotic-susceptible community-acquired (CA) MRSAs, such as ST22-IV and PVL-positive ST30-IV, in recent years after the turn of the century. Nonetheless, reports of livestock-associated (LA) MRSAs remain few in the region.

Detection of Methicillin Resistance and β-Lactamase Production in Staphylococcus aureus Isolates: A Cross Sectional Study from a Tertiary Care Hospital

Nosocomial infections are proving to be a menace for the whole health care system, with methicillin resistant Staphylococcus aureus (MRSA) being a very notorious causative agent. Along with the role of mecA gene producing penicillin-binding protein (PBP2a), production of beta-lactamase enzyme by Staphylococcus aureus makes the organism resistant to all β-lactam agents. This study aims at phenotypic detection of methicillin resistance and β-Lactamase production in all S. aureus isolates by Cefoxitin disk diffusion test and Penicillin zone-edge test, respectively. In this prospective cross-sectional study, samples were obtained from patients admitted to different departments and were processed according to the standard laboratory protocols. As per the CLSI guidelines, phenotypic detection of resistance to methicillin was done by Cefoxitin Disk Diffusion test, whereas production of beta-lactamase enzyme was phenotypically detected by penicillin zone edge test. Among 179 isolates of S. aureus, 116 (64.8%) were MRSA, whereas the remaining 63 (35.2%) isolates were methicillin-sensitive Staphylococcus aureus (MSSA). Staphylococcus aureus infection among ICU and non-ICU patients were found to be 24(13%) and 155(86.6%) respectively. Among 24 ICU patients, 19 had MRSA infection, whereas among 155 non-ICU patients, 97 had MRSA infection. Out of 63 MSSA isolates, only 2 (3.17%) were found to be sensitive to Penicillin by Zone-edge test, 04 isolates showed presence of β-lactamase production, while remaining 57 isolates were resistant to Penicillin. At the same time, several class of antibiotics were found to be ineffective against these MRSA isolates. Cases of methicillin-resistant and b–lactamase producing Staphylococcus aureus infections are on the rise in our hospital settings.

Metal nanoparticles functionalized with nutraceutical Kaempferitrin from edible Crotalaria juncea, exert potent antimicrobial and antibiofilm effects against Methicillin-resistant Staphylococcus aureus

Kaempferitrin (KF), a flavonol glycoside, was isolated from the edible plant Crotalaria juncea. Optimization for the synthesis of silver (AgNPs) and copper (CuNPs) nanoparticles using C. juncea extract and kaempferitrin were attempted for the first time. A detailed study on size and stability analysis have been reported. Efficacy of KF@AgNPs and KF@CuNPs against biofilm formation and planktonic mode of growth on methicillin-resistant Staphylococcus aureus (MRSA) along with possible mechanisms has been explored. Release of Cu(II) upon prolonged treatment with KF@CuNPs in the presence of MRSA was quantified through Alizarin red test, indicating the antibacterial effect is initiated by the CuNPs itself. Time kill curve depicted both the NPs have similar kill kinetics to curtail the pathogen and imaging with Crystal violet assay, Fluorescent live dead imaging and SEM analysis revealed a 60% reduction in biofilm formation at the Sub-MIC concentration of KF@AgNPs and KF@CuNPs. Furthermore, the membrane permeability and cell surface hydrophobicity were altered in the presence of both the NPs. The colony count from the in vivo infection zebrafish model in the treatment group showed a decline of > 1.8 fold for KF@AgNPs and > two fold for KF@CuNPs. Toxicity studies did not reveal any abnormality in liver and brain enzyme levels. Liver morphology images show no severe cytological alterations when treated with KF@AgNPs and were almost similar to the normal liver. Thus, KF@AgNPs was nontoxic and caused significant reduction in biofilm formation in MRSA, also reduced bacterial bioburden in the infected zebrafish, which has the potential to be explored in higher animal models.

The prevalence of virulence determinants in methicillin-resistant Staphylococcus aureus isolated from different infections in hospitalized patients in Poland

Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for hard-to-treat infections. The presence of 19 virulence genes in 120 MRSA isolates obtained from hospitalized patients and genetic relationships of these isolates were investigated. The eno (100%) and ebps (93.3%) genes encoding laminin- and elastin binding proteins, respectively, were ubiquitous. Other adhesion genes: fib (77.5%), fnbB (41.6%), bbp (40.8%), cna (30.8%) encoding proteins binding fibrinogen, fibronectin, bone sialoprotein and collagen, respectively, and map/eap (62.5%), encoding Eap, were also frequent. The etB and etD genes, encoding exfoliative toxins, were present in 15.6% and 12.5% isolates, respectively. The splA, splE and sspA, encoding serine protease were detected in 100%, 70.8% and 94.2% isolates, respectively. The tst gene, encoding toxic shock syndrome toxin-1 was found in 75% isolates. The cna, map/eap and tst genes were the most common in wound isolates and much less common in blood isolates. We identified 45 different spa types, t003 (21.7%) and t008 (18.8%) being the most common. The t003 was the most frequent among isolates from the respiratory tract (35.5%), while t008 in blood isolates (40%). Identification of virulence factors of MRSA is important for evaluation of pathogen transmission rate and disease development.

Inherent and Composite Hydrogels as Promising Materials to Limit Antimicrobial Resistance

Antibiotic resistance has increased significantly in the recent years, and has become a global problem for human health and the environment. As a result, several technologies for the controlling of health-care associated infections have been developed over the years. Thus, the most recent findings in hydrogel fabrication, particularly antimicrobial hydrogels, could offer valuable solutions for these biomedical challenges. In this review, we discuss the most promising strategies in the development of antimicrobial hydrogels and the application of hydrogels in the treatment of microbial infections. The latest advances in the development of inherently and composite antimicrobial hydrogels will be discussed, as well as hydrogels as carriers of antimicrobials, with a focus on antibiotics, metal nanoparticles, antimicrobial peptides, and biological extracts. The emergence of CRISR-Cas9 technology for removing the antimicrobial resistance has led the necessity of new and performant carriers for delivery of the CRISPR-Cas9 system. Different delivery systems, such as composite hydrogels and many types of nanoparticles, attracted a great deal of attention and will be also discussed in this review.

Livestock-Associated Meticillin-Resistant Staphylococcus aureus—Current Situation and Impact From a One Health Perspective

Purpose of Review

In this article, we aim to provide an overview of the occurrence and characteristics of livestock-associated (LA-) meticillin-resistant Staphylococcus aureus (MRSA). We further question the role of LA-MRSA as a potential foodborne pathogen. We investigate recent findings and developments from a One Health perspective also highlighting current strategies and initiatives aiming to improve reporting, control, and prevention of LA-MRSA.

Recent Findings

While the overall number of invasive MRSA infections in humans is decreasing (in most European countries and the USA) or steadily increasing (in the Asia-Pacific region), the role of LA-MRSA as causative agent of invasive disease and as potential foodborne pathogen is still poorly understood. LA-MRSA prevalence in livestock remains high in many geographical regions and the acquisition of new virulence and resistance determinants constitutes a growing threat for human health.

Summary

The true incidence of LA-MRSA infections due to occupational exposure is unknown. Improved MRSA monitoring and tracking procedures are urgently needed. Strain typing is crucial to enable improved understanding of the impact of LA-MRSA on human and animal health.

Filling the gaps in the global prevalence map of clinical antimicrobial resistance

Surveillance is critical in containing globally increasing antimicrobial resistance (AMR). Affordable methodologies to prioritize AMR surveillance efforts are urgently needed, especially in low- and middle-income countries (LMICs), where resources are limited. While socioeconomic characteristics correlate with clinical AMR prevalence, this correlation has not yet been used to estimate AMR prevalence in countries lacking surveillance. We captured the statistical relationship between AMR prevalence and socioeconomic characteristics in a suite of beta-binomial principal component regression models for nine pathogens resistant to 19 (classes of) antibiotics. Prevalence data from ResistanceMap were combined with socioeconomic profiles constructed from 5,595 World Bank indicators. Cross-validated models were used to estimate clinical AMR prevalence and temporal trends for countries lacking data. Our approach provides robust estimates of clinical AMR prevalence in LMICs for most priority pathogens (cross-validated q ² > 0.78 for six out of nine pathogens). By supplementing surveillance data, 87% of all countries worldwide, which represent 99% of the global population, are now informed. Depending on priority pathogen, our estimates benefit 2.1 to 4.9 billion people living in countries with currently insufficient diagnostic capacity. By estimating AMR prevalence worldwide, our approach allows for a data-driven prioritization of surveillance efforts. For carbapenem-resistant Acinetobacter baumannii and third-generation cephalosporin-resistant Escherichia coli, specific countries of interest are located in the Middle East, based on the magnitude of estimates; sub-Saharan Africa, based on the relative prevalence increase over 1998 to 2017; and the Pacific Islands, based on improving overall model coverage and performance.

Antimicrobial resistance and genotyping of Staphylococcus aureus obtained from food animals in Sichuan Province, China

Background

Staphylococcus aureus (S. aureus), especially methicillin-resistant Staphylococcus aureus (MRSA), is considered a common zoonotic pathogen, causing severe infections. The objective of this study was to investigate the antimicrobial susceptibility, resistance genes and molecular epidemiology among MRSA and methicillin-susceptible Staphylococcus aureus (MSSA) isolated from food animals in Sichuan Province, China.

Methods

This study was conducted on 236 S. aureus isolates. All isolates were subjected to antimicrobial susceptibility testing by using a standard microbroth dilution method. The Polymerase Chain Reaction (PCR) was performed to identify genes encoding the β-lactams resistance (blaZ, mecA), macrolides (ermA, ermB, ermC) and aminoglycosides (aacA-aphD). The molecular structures and genomic relatedness of MRSA isolates were determined by staphylococcal chromosome cassette mec (SCCmec) typing and pulsed-field gel electrophoresis (PFGE), respectively.

Results

Among 236 isolates, 24 (10.17 %) were recognized as MRSA. MRSA isolates showed different resistance rates to 11 antimicrobials ranging from 33.33 to 100 %, while for MSSA isolates the rates varied from 8.02 to 91.51 %. Multi-drug resistance phenotype was found in all MRSA isolates. The ermC gene encoding macrolides-lincosamides-streptogramin B was the most prevalent gene detected in 87.29 % of the S. aureus isolates, followed by ermB (83.05 %), blaZ (63.98 %), aacA-aphD (44.07 %), ermA (11.44 %) and mecA (11.02 %) genes. The prevalence of resistance genes in MRSA isolates was significantly higher than that of MSSA. Regarding the molecular morphology, SCCmec III (12/24, 50 %) was the most common SCCmec type. Furthermore, the PFGE typing showed that 24 MRSA were divided into 15 cluster groups (A to O), the major pulsotype J encompassed 25 % of MRSA isolates.

Conclusions

The S. aureus isolates from food animals in Sichuan province of China have severe antimicrobials resistance with various resistance genes, especially MRSA isolates. Additionally, the genetic pool of MRSA isolates is diverse and complex, and further investigation is necessary.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-02884-z.

Antibiotic Resistance Pattern of Staphylococcus Aureus Isolated From Pediatrics With Ocular Infections: A 6-Year Hospital-Based Study in China

Staphylococcus aureus (S. aureus) is an important pathogen of ocular infections in pediatrics. The study aimed to identify the prevalence and resistance pattern of S. aureus, especially methicillin-resistant S. aureus (MRSA), in Chinese children with ocular infections. All patients with S. aureus infections were reviewed at a tertiary children's hospital during 2015-2020, and those with ocular infections were investigated for susceptibility results. Of 1,668 S. aureus strains, there were 177 unique isolates from ocular infection. Among them, 45 (25.4%) were MRSA and 132 (74.6%) were methicillin-sensitive S. aureus (MSSA). The proportion of MRSA did not change over time. Most of the strains were obtained from the neonate ward and ophthalmology department (n = 88, 49.7%, and n = 85, 48.0%, respectively), while eye secretion and pus were the main specimen types (n = 128, 72.3%, and n = 37, 20.9%, respectively). MRSA was significantly resistant against penicillin class (97.8%), erythromycin (71.1%), clindamycin (71.1%), and tetracycline (32.1%), with a high multidrug resistance (MDR) rate of 71.1%. However, MRSA was highly sensitive to levofloxacin. Resistance rates against erythromycin and ciprofloxacin as well as MDR percentage all increased among MSSA in children above 1 year of age, ophthalmology department, and outpatient population and decreased in eye secretion specimen. The mean resistance percentage remained stable for MRSA and MSSA during the study period. The survey of ocular S. aureus pathogens in pediatrics and their antibiotic resistance patterns helps in clinical treatment. MRSA with many strains demonstrating MDR is highly prevalent in children with ocular infections in Southeast China. Levofloxacin is an effective topical antibiotic for ocular MRSA infection, while erythromycin has a high resistance rate. The antibiotic resistance patterns of MRSA and MSSA differs and varies by different stratifications. A cautious use of antibiotics should be considered.

Prevalence of MDR organism (MDRO) carriage in children and their household members in Siem Reap Province, Cambodia

BACKGROUND

The rising incidence of infections caused by MDR organisms (MDROs) poses a significant public health threat. However, little has been reported regarding community MDRO carriage in low- and middle-income countries.

METHODS

We conducted a cross-sectional study in Siem Reap, Cambodia comparing hospital-associated households, in which an index child (age: 2-14 years) had been hospitalized for at least 48 h in the preceding 2-4 weeks, with matched community households on the same street, in which no other child had a recent history of hospitalization. Participants were interviewed using a survey questionnaire and tested for carriage of MRSA, ESBL-producing Enterobacterales (ESBL-E) and carbapenemase-producing Enterobacterales (CPE) by culture followed by antibiotic susceptibility testing. We used logistic regression analysis to analyse associations between collected variables and MDRO carriage.

RESULTS

Forty-two pairs of households including 376 participants with 376 nasal swabs and 290 stool specimens were included in final analysis. MRSA was isolated from 26 specimens (6.9%). ESBL-producing Escherichia coli was detected in 269 specimens (92.8%) whereas ESBL-producing Klebsiella pneumoniae was isolated from 128 specimens (44.1%), of which 123 (42.4%) were co-colonized with ESBL-producing E. coli. Six (2.1%) specimens tested positive for CPE (4 E. coli and 2 K. pneumoniae). The prevalence ratios for MRSA, ESBL-producing E. coli and ESBL-producing K. pneumoniae carriage did not differ significantly in hospital-associated households and hospitalized children compared with their counterparts.

CONCLUSIONS

The high prevalence of ESBL-E across both household types suggests that MDRO reservoirs are common in the community. Ongoing genomic analyses will help to understand the epidemiology and course of MDRO spread.

A Systemic Literature Review and Meta-Analysis Reporting the Prevalence and Impact of Methicillin-Resistant Staphylococcus aureus Infection in India

Aim and objective

This systematic review and meta-analysis was conducted to assess the prevalence, burden and epidemiology of methicillin-resistant S. aureus (MRSA). This systemic review was also aimed to highlight the challenges in the diagnosis and management of methicillin-resistant S. aureus (MRSA) in India (for all age groups). We also examined the published literature on the available treatment options and the role of prevention in the management of MRSA in India. By summarizing the currently available data, our objectives were to highlight the need for the prevention of MRSA infections and also emphasize the role of vaccination in the prevention of MRSA infections in India.

Methodology

Electronic databases such as PubMed and databases of the National Institute of Science Communication and Information Resources and Indian Council of Medical Research Embase were searched for relevant literature published from 2005/01/01 to 2020/05/13 in English language, according to the predefined inclusion and exclusion criteria. A manual search was also conducted using the key term "MRSA 'or' Methicillin Resistant Staphylococcus aureus 'and' India." An independent reviewer extracted data from the studies using a structured Microsoft Excel spreadsheet, and a meta-analysis of proportion for MRSA prevalence with a corresponding 95% confidence interval (CI) for all included individual studies were performed.

Result

A total of 34 studies involving 16 237 patients were included in the final meta-analysis. The pooled proportion of patients with MRSA infection was 26.8% (95% CI: 23.2%-30.7%). The MRSA infection was more prevalent among male patients (60.4%; 95% CI: 53.9%-66.5%) as compared to female patients (39.6%; 95% CI: 33.5%-46.1%), while the prevalence of MRSA was higher among adults (18 years and above; 32%; 95% CI: 5%-80%) in comparison to pediatric patients (0-18 years; 68%; 95% CI: 20%-94.8%). The degree of heterogeneity was found to be significant.

Conclusion

The prevalence of MRSA in India was relatively high at 27% with a higher proportion observed among men aged >18 years. The high prevalence of MRSA infections in India necessitates the implementation of surveillance and preventive measures to combat the spread of MRSA in both hospital and community settings.

An Immunodominant Epitope-Specific Monoclonal Antibody Cocktail Improves Survival in a Mouse Model of Staphylococcus aureus Bacteremia

To date, no vaccine or monoclonal antibody (mAb) against Staphylococcus aureus has been approved for use in humans. Our laboratory has developed a 5-antigen S. aureus vaccine (rFSAV), which is now under efficacy evaluation in a phase 2 clinical trial. In the current study, using overlapping peptides and antiserum from rFSAV-immunized volunteers, we identified 7 B-cell immunodominant epitopes on 4 antigens in rFSAV, including 5 novel epitopes (Hla48-65, IsdB402-419, IsdB432-449, SEB78-95, and MntC7-24). Ten immunodominant epitope mAbs were generated against these epitopes, and all of them exhibited partial protection in a mouse sepsis model. Four robust mAbs were used together as an mAb cocktail to prevent methicillin-resistant S. aureus strain 252 infection. The results showed that the mAb cocktail was efficient in combating S. aureus infection and that its protective efficacy correlated with a reduced bacterial burden and decreased infection pathology, which demonstrates that the mAb cocktail is a promising S. aureus vaccine candidate.

Development, Evaluation, and Pharmacokinetic Assessment of Polymeric Microarray Patches for Transdermal Delivery of Vancomycin Hydrochloride

Methicillin-resistant Staphylococcus aureus (MRSA) can cause harmful and potentially deadly infections. Vancomycin remains the first-line antibiotic treatment for MRSA-derived infections. Nevertheless, as a peptide drug, it is poorly absorbed when administered orally because of its high molecular weight and low permeability in the gastrointestinal tract and is therefore administered intravenously for the treatment of systemic diseases. In order to circumvent some of the many drawbacks associated with intravenous injection, other routes of drug delivery should be investigated. One of the strategies which has been employed to enhance transdermal drug delivery is based on microarray patches (MAPs). This work, for the first time, describes successful transdermal delivery of vancomycin hydrochloride (VCL) using dissolving MAPs (DMAPs) and hydrogel-forming MAPs (HFMAPs). VCL was formulated into DMAPs and reservoirs [film dosage forms, lyophilized wafers, and compressed tablets (CSTs)] using excipients such as poly(vinyl pyrrolidone), poly(vinyl alcohol), sodium hyaluronate, d-sorbitol, and glycerol. In this study, HFMAPs were manufactured using aqueous blends containing poly(methylvinyl ether-co-maleic acid) cross-linked by esterification with poly(ethylene glycol). The VCL-loaded CSTs (60% w/w VCL) were the most promising reservoirs to be integrated with HFMAPs based on the physicochemical evaluations performed. Both HFMAPs and DMAPs successfully delivered VCL in ex vivo studies with the percentage of drug that permeated across the neonatal porcine skin recorded at 46.39 ± 8.04 and 7.99 ± 0.98%, respectively. In in vivo studies, the area under the plasma concentration time curve from time zero to infinity (AUC_0-∞) values of 162.04 ± 61.84 and 61.01 ± 28.50 μg h/mL were achieved following the application of HFMAPs and DMAPs, respectively. In comparison, the AUC_0-∞ of HFMAPs was significantly greater than that of the oral administration control group, which showed an AUC_0-∞ of 30.50 ± 9.18 μg h/mL (p < 0.05). This work demonstrates that transdermal delivery of VCL is feasible using DMAPs and HFMAPs and could prove effective in the treatment of infectious diseases caused by MRSA, such as skin and soft tissue infections, lymphatic-related infections, and neonatal sepsis.

Antimicrobial Resistance in ESKAPE Pathogens

Antimicrobial-resistant ESKAPE ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens represent a global threat to human health. The acquisition of antimicrobial resistance genes by ESKAPE pathogens has reduced the treatment options for serious infections, increased the burden of disease, and increased death rates due to treatment failure and requires a coordinated global response for antimicrobial resistance surveillance. This looming health threat has restimulated interest in the development of new antimicrobial therapies, has demanded the need for better patient care, and has facilitated heightened governance over stewardship practices.

Antimicrobial Resistance in ESKAPE Pathogens

Antimicrobial-resistant ESKAPE ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens represent a global threat to human health. The acquisition of antimicrobial resistance genes by ESKAPE pathogens has reduced the treatment options for serious infections, increased the burden of disease, and increased death rates due to treatment failure and requires a coordinated global response for antimicrobial resistance surveillance. This looming health threat has restimulated interest in the development of new antimicrobial therapies, has demanded the need for better patient care, and has facilitated heightened governance over stewardship practices.

Case-based surveillance of antimicrobial resistance with full susceptibility profiles

Surveillance of antimicrobial resistance (AMR) is essential for clinical decision-making and for public health authorities to monitor patterns in resistance and evaluate the effectiveness of interventions and control measures. Existing AMR surveillance is typically based on reports from hospital laboratories and public health laboratories, comprising reports of pathogen frequencies and resistance frequencies among each species detected. Here we propose an improved framework for AMR surveillance, in which the unit of surveillance is patients with specific conditions, rather than biological samples of a particular type. In this 'case-based' surveillance, denominators as well as numerators will be clearly defined with clinical relevance and more comparable at the local, national and international level. In locations with sufficient resources, individual-based data on patient characteristics and full antibiotic susceptibility profiles would provide high-quality evidence for monitoring resistant pathogens of clinical importance, clinical treatment of infections and public health responses to outbreaks of infections with resistant bacteria.

Recent advances in Staphylococcus aureus infection: focus on vaccine development

Staphylococcus aureus normally colonizes the nasal cavity and pharynx. After breaching the normal habitat, the organism is able to cause a number of infections at any site of the body. The development of antibiotic resistance has created a global challenge for treating infections. Therefore, protection by vaccines may provide valuable measures. Currently, several vaccine candidates have been prepared which are either in preclinical phase or in early clinical phase, whereas several candidates have failed to show a protective efficacy in human subjects. Approaches have also been made in the development of monoclonal or polyclonal antibodies for passive immunization to protect from S. aureus infections. Therefore, in this review we have summarized the findings of recently published scientific literature to make a concise report.