Prevalence of methicillin resistant Staphylococcus aureus [MRSA] colonization or carriage among health-care workers

Bacterial burden and drug-resistant bacteria in healthcare workers' mobile phones: a study in Puerto Rican outpatient clinics

Background

Mobile phones used by healthcare workers (HCWs) in hospitals are significant reservoirs of drug-resistant bacteria responsible for hospital-acquired infections (HAIs).

Aim

The objective of this study was to assess the level of contamination with such bacteria in outpatient clinics.

Methods

Swabs from 83 HCWs' mobile phones were processed using standard biochemical and enzymatic procedures to identify pathogenic bacteria. β-Lactamase tests, antimicrobial susceptibility tests, screening for extended-spectrum β-lactamase (ESBL), and carbapenemase production were performed according to CLSI guidelines. Molecular detection of multi-drug-resistant genes (mecA in Staphylococcus aureus and kpc/ndm carbapenemases in Klebsiella pneumoniae and Acinetobacter spp.) was performed using multiplex real-time polymerase chain reaction.

Findings

The overall prevalence of mobile phone contamination with one or more bacteria was 100%. A total of 51 Gram-positive and 44 Gram-negative isolates, including 20 coagulase-negative staphylococci (CoNS), 20 S. aureus (0 meticillin-resistant S. aureus), 11 Acinetobacter spp. and 10 K. pneumoniae were isolated. β-Lactamase production was detected in 45% of CoNS and 30% of S. aureus. Panton-Valentine Leukocidin (PVL) toxin gene in S. aureus was found in 20% (4/20) of the isolates. Twenty (20%) and 13% of the Acinetobacter spp. and K. pneumoniae isolates, respectively, were ESBL but not carbapenemase producers.

Conclusions

The presence of HAI-causing organisms on mobile phones used by HCWs in outpatient clinics necessitates the implementation of infection control measures to mitigate the risk of cross-contamination in critical healthcare settings.

Colonization of methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci and its associated factors in cancer patients at the University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia

BACKGROUND

Cancer patients are predisposed to methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci colonization. However, the prevalence of these pathogens among cancer cases in Northwestern Ethiopia remains underreported.

OBJECTIVE

To determine the prevalence of colonization of methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci and associated factors among cancer patients at the University of Gondar Comprehensive Specialized Hospital, Northwestern Ethiopia.

METHOD

A cross-sectional study enrolled 288 confirmed cancer participants through stratified systematic random sampling, gathering socio-demographic and clinical data via pretested structured questionnaires from May 1 to July 30, 2023. Each participant provided two specimens: a nasal swab and a fecal sample. Nasal swabs were collected using sterile swabs, inserted at least 1 cm into each nostril, and rotated against the nasal membrane for 10 to 15 seconds, which were then placed in Amies transport medium. Fecal specimens were collected in leak-proof plastic containers, swabbed, and transferred to Cary Blair transport medium. Nasal swabs and fecal specimens were cultured on Mannitol salt agar at 37°C for Staphylococcus aureus identification, which was confirmed by coagulase testing and Gram staining. Enterococci were cultured on Bile esculin agar at 43°C and identified at the genus level by cultural characteristics, with confirmation through Gram reaction and catalase tests. Antibiotic susceptibility was evaluated using the Kirby-Bauer disk diffusion method, with minimum inhibitory concentrations for vancomycin determined via E-test strips. To detect methicillin-resistant Staphylococcus aureus, a cefoxitin disk was used. Inducible clindamycin resistance in Staphylococcus aureus was determined by the D test. Epi-info version 7 and SPSS version 27 were used for data entry and data analysis, respectively. The Pearson Chi-Square test was initially used to evaluate the association between factors and outcomes as the preliminary analysis, with a significance threshold of p <  0.05. Variables meeting this criterion underwent bivariable and multivariable logistic regression analyses, using p-value cutoffs of <  0.2 for bivariable and <  0.05 for multivariable analyses.

RESULT

The study involved 288 participants, with 51.0% being men and a mean age of 45.6 years. The prevalence of methicillin-resistant Staphylococcus aureus was 11.1% (95% CI: 7.5-14.7%), while vancomycin-resistant Enterococci had a prevalence of 2.8% (95% CI: 0.9-4.7%). Inducible clindamycin-resistant Staphylococcus aureus comprised 13.5% of the isolates. The multidrug-resistant proportion of Staphylococcus aureus and Enterococci were 56.2% and 55.2%, respectively. Both organisms exhibited the highest resistance to the antibiotic classes of penicillin and tetracycline. Significant associations were identified between methicillin-resistant Staphylococcus aureus colonization and low absolute neutrophil count (AOR =  13.050, 95% CI: 1.362-125.00, P =  0.026), and between vancomycin-resistant Enterococci colonization and having undergone an invasive procedure (AOR =  8.648, 95% CI: 1.870-39.992, P =  0.006).

CONCLUSION

The study reveals a significant prevalence of methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci colonization among cancer patients, raising public health concerns. High antibiotic resistance rates complicate treatment and may impact patient outcomes. Notably, the high inducible clindamycin resistance report, highlights the need for D-testing. Screening for methicillin-resistant Staphylococcus aureus is recommended as an important antibiotic stewardship measure, while early detection of vancomycin-resistant Enterococci colonization is crucial to reduce complications.

Clindamycin-Loaded Polyhydroxyalkanoate Nanoparticles for the Treatment of Methicillin-Resistant Staphylococcus aureus-Infected Wounds

Background/Objectives: Owing to the growing resistance of methicillin-resistant Staphylococcus aureus (MRSA) to conventional antibiotics, the development of innovative therapeutic strategies for the treatment of MRSA-infected cutaneous wounds poses a significant challenge. Methods: Here, by using polyhydroxyalkanoates (PHA), emerging biodegradable and biocompatible polymers naturally produced by various microorganisms, we developed clindamycin-loaded PHA nanoparticles (Cly-PHA NPs) as a novel approach for the treatment of MRSA-infected cutaneous wounds. Results: Cly-PHA NPs were characterized in terms of mean particle size (216.2 ± 38.9 nm), polydispersity index (0.093 ± 0.03), zeta potential (11.3 ± 0.5 mV), and drug loading (6.76 ± 0.19%). Owing to the sustained release of clindamycin over 2 days provided by the PHA, Cly-PHA NPs exhibited potent antibacterial effects against MRSA. Furthermore, Cly-PHA NPs significantly facilitated wound healing in a mouse model of MRSA-infected full-thickness wounds by effectively eradicating MRSA from the wound bed. Conclusions: Therefore, our results suggest that Cly-PHA NPs offer a promising approach for combating MRSA infections and accelerating cutaneous wound healing.

Epidemiology of Methicillin-Resistant Staphylococcus Aureus in Arab Countries of the Middle East and North African (MENA) Region

Available data suggest a high burden of methicillin-resistant staphylococcus aureus (MRSA) in Arab countries of the Middle East and North Africa (MENA). To review the MRSA rates and molecular epidemiology in this region, we used PubMed search engine to identify relative articles published from January 2005 to December 2019. Great heterogeneity in reported rates was expectedly seen. Nasal MRSA colonization ranged from 2%–16% in Gulf Cooperation Council (GCC), 1–9% in the Levant, and 0.2%–9% in North African Arab states. Infective MRSA rates ranged from 9%–38% in GCC, 28%–67% in the Levant, and 28%–57% in North African states. Studies demonstrated a wide clonal diversity in the MENA. The most common molecular types belonged to 5 clonal complexes (CC) known to spread worldwide: CC5, CC8, CC22, CC30, and CC80. The most prevalent strains had genotypes related to the European community-acquired MRSA (CA-MRSA), Brazilian/Hungarian hospital-acquired MRSA (HA-MRSA), UK-EMRSA-15 HA-MRSA, and USA300 CA-MRSA. Finally, significant antimicrobial resistance was seen in the region with variation in patterns depending on location and clonal type. For a more accurate assessment of MRSA epidemiology and burden, the Arab countries need to implement national surveillance systems.

Nasal Carriage and Methicillin Resistance of Staphylococcus aureus among Schoolchildren in Sana'a City, Yemen

Background

Staphylococcus aureus (S. aureus) is a frequent cause of serious health problems with high morbidity and mortality. The risk of S. aureus infections is increased with the emergence of methicillin-resistant S. aureus (MRSA). This study aims to determine the nasal carriage rate of both S. aureus and MRSA among schoolchildren in Sana'a city.

Methods

This is a cross-sectional study conducted from January 2018 to May 2020. Five hundred and thirty-six students were enrolled. Their age ranged from 5 to 19 years with the mean age and standard deviation equal to 13.3 ± 3.5 years. Nasal swabs were collected from each student for culturing and methicillin susceptibility testing.

Results

Students with positive culture were 271 (51%) males and 265 (49%) females. S. aureus was isolated from 129 (24%) students whereas the overall prevalence of MRSA was 8 (1.5%). S. aureus was significantly recovered from students at the age group of 10–14 years (χ² = 7.02; p=0.03), females than males (OR = 1.96; χ² = 10.75; p=0.001), and students who were admitted into hospitals (OR = 1.6; χ² = 4.89; p=0.03). Nevertheless, there were no significant differences between MRSA carriage and students' age (χ² = 2.3; p=0.32), gender (OR = 1.02; χ² = 0.001; p=0.63), and hospital admission (OR = 1.4; χ² = 0.25; p=0.62).

Conclusions

The prevalence of MRSA is low among schoolchildren in Sana'a city. Age, gender, and previous hospital admission were statistically associated with nasal carriage of S. aureus but not MRSA nasal carriage.

Constellation of methicillin-resistant genomic islands (SCCmec) among nasal meticillin-resistant Staphylococcus aureus isolates

The apprehensiveness for the knowledge vacuum on existential threat of nasal carriage of pvl+ healthcare-acquired meticillin-resistant Staphylococcus aureus (HA-MRSA) strains amongst subjects in hospitals have led us to pursue a grasp on the constellation of staphylococcal cassette chromosome mec (SCCmec) types and pvl gene among mecA positive MRSA nasal strains. This was accomplished by phenotypic (catalase, coagulase, Microgen staph ID, ORSAB) and genotypic (polymerase chain reaction) biotyping techniques. All the mecA+ strains harboured the SCCmec gene; SCCmec type I prevailed in 43.75% and pvl was found in 42.1% of the isolates. Dual carriage of mecA and pvl genes occurred in six (37.5%, n = 6/16) strains. Overall, majority of the mecA+ MRSA strains documented in this study carried SCCmec elements of the HA genotype with a hint of community-acquired (CA)genotype suggesting a possible coexistence of both HA-MRSA and community-acquiredhealthcare-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) strains. Consequently, the implementation of methodical surveillance is needed for the evaluation of potential shifts in directionality of (HA-MRSA/CA-MRSA) pvl+ MRSA clones in our hospitals for effective and prudent antimicrobial stewardship.

Transmission and Long-Term Colonization Patterns of Staphylococcus aureus in a Nursing Home

Nursing homes might create an environment favorable for the transmission of Staphylococcus aureus because of the presence of hospitalized elderly, overcrowding and close contacts among people. We aimed at identifying risk factors for S. aureus colonization and determining the genetic relatedness of isolates demonstrating transmission among people. We investigated 736 swab samples from 92 residents and personnel for the presence of S. aureus. Swabs from anterior nares and throat were collected quarterly (2018) in a nursing home located in Poland. Genotyping was conducted using the multi-locus variable number of tandem repeats fingerprinting (MLVF) method. We observed high seasonal variation in the proportion of participants colonized with methicillin-resistant Staphylococcus aureus (MRSA) strains (0% to 13.5%). A multivariate analysis revealed that residents aged more than 85 years old are at risk for becoming intermittent S. aureus carriers (p = 0.013). The MLVF analysis revealed a high genetic diversity among methicillin-sensitive S. aureus (MSSA) strains and close genetic relatedness between MRSA strains. We proved the advanced aged were predisposed to intermittent S. aureus carriage. Genotyping revealed the transmission of S. aureus among the participants living in a closed environment. A high genetic relatedness among isolated MRSA suggests its clonal spread in the nursing home.

The relationship between hand hygiene practices and nasal Staphylococcus aureus carriage in healthcare workers

Background:

The nasal carriage rate of Staphylococcus aureus in healthcare workers (HCWs) is higher than the general population. Their hands serve as vectors for transmitting S.aureus colonized in the nose to patients.

Objectives:

To determine the rate of nasal S.aureus carriage and methicillin resistance in HCWs and to evaluate the relationship between carriage and personal risk factors and hand hygiene behaviors.

Methods:

The questionnaire included questions about sociodemographic characteristics, occupational and personal risk factors for S.aureus carriage, the “Hand Hygiene Belief Scale (HHBS),” and “Hand Hygiene Practices Inventory (HHPI)”. Nasal culture was taken from all participants. Presence of S.aureus, methicillin and mupirocin resistance were investigated in samples.

Results:

The study was carried out with 269 HCWs. The prevalence of S.aureus carriage was 20.1% (n:54). Among 54 S.aureus carriers, only one person had MRSA (0.37%). All S.aureus isolates were susceptible to mupirocin. S.aureus carriage was found to be significantly lower in the smoker group (p:0.015) and in the personnel wearing gloves during the procedures of each patient (p:0.002). S.aureus culture positivity was found to decrease significantly with increasing handwashing frequency (p:0.003). The mean HHPI score was higher in women (p:0.001). The mean HHPI score was lower in the group with nasal carriers than in non-carriers (p:0.176).

Conclusion:

The knowledge of hand hygiene practices, high frequency of handwashing, and wearing different gloves during the procedure of each patient decrease S.aureus nasal carriage in HCWs. In addition mupirocin is still effective in nasal S.aureus carriers.

Environmental fate of pharmaceutical compounds and antimicrobial-resistant bacteria in hospital effluents, and contributions to pollutant loads in the surface waters in Japan

Environmental fate of 58 pharmaceutical compounds (PhCs) grouped into 11 therapeutic classes in the three different waters, hospital effluent, sewage treatment plant (STP) and river water, was estimated by combination of their quantitative concentration analysis and evaluation of their extent of contribution as loading sources. At the same time, distribution of six classes of antimicrobial-resistant bacteria (AMRB) in the same water samples was estimated by screening of individual PhC-resistant microbes grown on each specific chromogenic medium. The results indicate that 48 PhCs were detected ranged from 1 ng/L (losartan carboxylic acid) to 228 μg/L (acetaminophen sulfate) in hospital effluent, and contribution of the pollution load derived from hospital effluent to STP influent was estimated as 0.1% to 15%. On the other hand, contribution of STP effluent to river water was high, 32% to 60% for antibacterials, antipertensives and X-ray contrast media. In the cases for AMRB, detected numbers of colonies of AMRB in hospital effluent ranged from 29 CFU/mL to 1805 CFU/mL, and the estimated contribution of the AMRB pollution load derived from hospital effluent to STP influent was as low as 0.1% (levofloxacin and olmesartan) to 5.1% (N-desmethyl tamoxifen). Although the contribution of STPs as loading sources of PhCs and AMRB in surface waters was large, ozonation as an advanced water treatment system effectively removed a wide range of both PhCs and AMRB in water samples. These results suggest the importance of reducing environmental pollutant loads (not only at STPs but also at medical facilities) before being discharged into the surface waters, to both conserve water and keep the water environment safe. To our knowledge, this is the first report to show the distribution and contribution of AMRB from hospital effluent to the surface waters.

Methicillin-resistant Staphylococcus aureus tracking spread among health-care workers and hospitalized patients in critical wards at a university hospital, Tehran, Iran

Health-care workers may serve as a reservoir for dissemination of methicillin-resistant Staphylococcus aureus (MRSA) to patients in hospital settings. The present study aimed to screen MRSA in nasal swabs of health-care workers and clinical specimens from patients and investigate the possible relationship between these isolates at a university hospital in Tehran, Iran. Additionally, we aimed to identify potential risk factors for MRSA colonization in health-care workers. Staphylococcus aureus strains were isolated from health-care workers and inpatients who completed a questionnaire on risk factors. Cefoxitin disc diffusion test was also used for detection of MRSA. Moreover, all of the MRSA isolates were subjected to pulsed-field gel electrophoresis (PFGE). Colonization rate of MRSA among health-care workers was 22.5%. Furthermore, out of 24 S. aureus isolates obtained from patients, nine (37.5%) were MRSA. Regarding risk factors, the prevalence of nasal MRSA carriage among hospital personnel who used masks was significantly lower than in those without masks (p 0.007). Using PFGE, 10 clusters and 14 singletons were identified among the MRSA isolates. In this regard, most of the MRSA isolates recovered from health-care carriers and patients in intensive care wards, especially general intensive care units, were grouped in certain clusters, indicating intra-ward transmission of the mentioned isolates in these restricted areas. We concluded that screening and decolonization of carriers, contact precautions, prudent use of antibiotics and implementation of active surveillance are recommended strategies for the prevention and control of MRSA transmission in hospital settings.

Streptomyces as a Prominent Resource of Future Anti-MRSA Drugs

Methicillin-resistant Staphylococcus aureus (MRSA) pose a significant health threat as they tend to cause severe infections in vulnerable populations and are difficult to treat due to a limited range of effective antibiotics and also their ability to form biofilm. These organisms were once limited to hospital acquired infections but are now widely present in the community and even in animals. Furthermore, these organisms are constantly evolving to develop resistance to more antibiotics. This results in a need for new clinically useful antibiotics and one potential source are the Streptomyces which have already been the source of several anti-MRSA drugs including vancomycin. There remain large numbers of Streptomyces potentially undiscovered in underexplored regions such as mangrove, deserts, marine, and freshwater environments as well as endophytes. Organisms from these regions also face significant challenges to survival which often result in the production of novel bioactive compounds, several of which have already shown promise in drug development. We review the various mechanisms of antibiotic resistance in MRSA and all the known compounds isolated from Streptomyces with anti-MRSA activity with a focus on those from underexplored regions. The isolation of the full array of compounds Streptomyces are potentially capable of producing in the laboratory has proven a challenge, we also review techniques that have been used to overcome this obstacle including genetic cluster analysis. Additionally, we review the in vivo work done thus far with promising compounds of Streptomyces origin as well as the animal models that could be used for this work.

Nasal Carriage of Methicillin-Resistant Staphylococcus aureus among Health Care Workers in Tertiary and Regional Hospitals in Dar es Salam, Tanzania

Methicillin-resistant Staphylococcus aureus (MRSA) among health care workers (HCWs) increases the risk of spreading the organism in hospital settings. A cross-sectional study was conducted between June and October 2016 among HCWs in tertiary and regional hospitals in Dar es Salaam, Tanzania, to determine the MRSA nasal carriage rate. Nasal swabs were collected from HCWs and cultured on mannitol salt agar. S. aureus was identified based on colonial morphology, Gram staining, catalase, coagulase, and DNase test results. MRSA was detected using the cefoxitin disk. Among 379 HCWs enrolled, 157/379 (41.4%) were colonized with S. aureus, of whom 59 (37.6%) were MRSA carriers giving an overall prevalence of 59/379 (15.6%). MRSA carriage was high among HCWs in Temeke (56.9%) and Amana (37.5%) regional hospitals. A high proportion of MRSA carriage was detected among nurses (35, 45.5%). MRSA isolates showed high resistance toward kanamycin (83.7%), gentamicin (83.1%), ciprofloxacin (71.2%), and trimethoprim-sulphamethoxazole (46.8%) compared to methicillin-sensitive S. aureus isolates (p ≤ 0.001). In conclusion, we found a high nasal carriage of MRSA and resistance to commonly prescribed antimicrobial agents among HCWs. Implementation of infection control measures including contact precautions, urgent reporting of MRSA laboratory results, and routine MRSA screening of HCWs is highly needed to reduce MRSA spreading.

Multidrug-resistant bacteria isolated from cell phones in five intensive care units: Exploratory dispersion analysis

Introduction

Cell phones are susceptible to bacterial contamination. The aim of this study was to characterize the bacterial isolates and to explore their dispersion in five Intensive Care Units (ICUs) over the time.

Methods

We performed a secondary analysis of non-fermenting Gram-negative bacteria and Gram-positive cocci isolated from a 5-month observational cohort study developed among health care workers' cell phones in five ICUs. Cell phones were sampled using a swab every 15 days. Antimicrobial resistance was determined by the minimum inhibitory concentration method. We constructed resistance phenotypes to group the isolates according to species and antimicrobial resistance pattern to explore dispersion through time.

Results

A total of 35 P. aeruginosa, 16 Acinetobacter spp., 30 S. aureus and 26 Enterococcus spp. were isolated from 491 phone samples. Multidrug resistance was 2.9% for P. aeruginosa, 31.3% for Acinetobacter spp., 46.7% for S. aureus and 80.8% for Enterococcus spp. The resistance to methicillin in S. aureus and to vancomycin in Enterococcus spp. was 26.7% and 42.3%, respectively. We did not observe distribution patterns or clusters over the time for P. aeruginosa, Acinetobacter spp. and Enterococcus spp. isolates. All the S. aureus isolates grouped into eight phenotypes. Interestingly, we observed S. aureus isolates with the same phenotype in consecutive and separate sampling dates in the same cell phone.

Conclusion

Cell phones are contaminated with highly harmful bacteria and potentially can maintain them for prolonged periods of time. These devices could be considered as a potential source of nosocomial infections in ICUs.

Aerobic Mesophilic, Coliform, Escherichia coli, and Staphylococcus aureus Counts of Raw Meat from the Formal and Informal Meat Sectors in South Africa

Foodborne disease (FBD) is a global public health concern, and foods from animal sources have been associated with outbreaks of food-related illness. In this study, animal carcasses from the two abattoirs (HT1 and HT2) in the formal meat sector (FMS) and slaughter points in the informal meat sector (INMS) were examined at two stages of slaughter (before washing and after washing) for aerobic colony counts (ACC) and total viable count (TCC), as well as Escherichia coli and Staphylococcus aureus count. At each stage, carcasses were sampled by swabbing at the neck, brisket, flank, and rump. ACC for beef, mutton, and pork carcasses at HT1 and HT2 before washing were between 2.5–5.8, 2.2–4.7, and 2.7–3.7 mean log CFU/cm², respectively, and TCC count before washing was highest on the neck of cattle (6.3 ± 2.4) and after washing was highest on the perineal of sheep (5.7 ± 6.9). In the INMS, TCC count was highest on the brisket (6.9 ± 3.2) and in the neck (5.5 ± 2.4). Higher ACC values of 6.2–6.7 mean log CFU/cm² were obtained in the INMS. The highest count for E. coli (4.2 mean log CFU/cm²) after washing was in the neck, while the highest count for S. aureus (4.0 mean log CFU/cm²) was in the flank. All bacteria count in the INMS exceeded acceptable limits, and washing did not significantly reduce microbial load in meat in the FMS and INMS. Bacteria count in the FMS and INMS exceeded acceptable standards. However, meat processed in the INMS poses a more significant risk of FBD to consumers.

Break Scrub to Take That Phone Call?

BACKGROUND

The American College of Surgeons reports that 60% of the hundreds of thousands of surgical site infections occurring annually are preventable. The practice of surgeons taking phone calls while remaining sterile in the operating field is often accomplished by interposing a sterile disposable towel between the phone and their glove. After completing the call, surgeons resume operating. The purpose of our study was to test the conceptual idea of whether bacteria transmit from an inanimate object, such as a telephone, to the gloves of a surgeon through a sterile disposable towel.

STUDY DESIGN

Glo Germ (Glo Germ Co), an ultraviolet light-enhanced particle powder sized to mimic bacteria, was placed on an inanimate surface and held with a sterile disposable operating room towel covering a sterile surgical glove. The glove was then inspected for Glo Germ using an ultraviolet light. Additionally, 18 operating room telephones were cultured and then held with a Sterile Disposable OR Towel (Medline Industries Inc) covering a sterile surgical glove. The surgical gloves were then cultured to determine if bacteria had transmitted from the telephone through the towel and onto the sterile glove.

RESULTS

The Glo Germ powder readily transmitted through the towel to the gloves. Median colony-forming units (CFU) on the cultured telephones for the 17 samples was 10, ranging from 1 to 35 CFUs. Of these 17 samples, 47% had transmission from the telephone to the glove, which was significantly greater than 0% (95% CI 26% to 69%, p < 0.001).

CONCLUSIONS

Sterile disposable operating room towels do not provide an effective barrier between bacteria present on operating room telephones and the otherwise sterile gloves of a surgeon.

Mechanistic insight into the photodynamic effect mediated by porphyrin-fullerene C60 dyads in solution and in Staphylococcus aureus cells

The photodynamic action mechanism sensitized by a non-charged porphyrin-fullerene C₆₀ dyad and its tetracationic analogue was investigated in solution and in Staphylococcus aureus cells.

Colonização bacteriana e resistência antimicrobiana em trabalhadores de saúde: revisão integrativa

Resumo Objetivo: Analisar as evidências científicas disponíveis na literatura sobre os microrganismos que colonizam os trabalhadores de saúde e sua associação com a resistência a antimicrobianos. Métodos: Revisão integrativa de literatura. A busca dos estudos primários foi realizada nas bases de informação: National Library of Medicine National Institutes of Health, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Scopus e Biblioteca virtual em saúde. Os descritores utilizados foram aplicados de acordo com particularidades de cada base de dados e obtidos por consulta nos Descritores de Ciências em Saúde e Medical Subject Headings. Resultados: A revisão foi composta de 14 estudos primários. Na análise das amostras as pesquisas encontraram principalmente Staphylococcus aureus e Staphylococcus aureus resistente a meticilina colonizando os trabalhadores de saúde. A resistência das bactérias à clindamicina e oxacilina apresentaram maior destaque nas amostras. Conclusão: O Staphylococcus aureus foi evidenciado nos estudos como principal bactéria colonizadora dos trabalhadores de saúde. A preocupação é que essas bactérias apresentam grande capacidade de resistência aos antibióticos beta-lactâmicos.

Stable oligonucleotide-functionalized gold nanosensors for environmental biocontaminant monitoring

The global propagation of environmental biocontaminants such as antibiotic resistant pathogens and their antibiotic resistance genes (ARGs) is a public health concern that highlights the need for improved monitoring strategies. Here, we demonstrate the environmental stability and applicability of an oligonucleotide-functionalized gold nanosensor. The mecA ARG was targeted as model biocontaminant due to its presence in clinically-relevant pathogens and to its emergence as an environmental contaminant. mecA-specific nanosensors were tested for antibiotic resistance gene (ARG) detection in ARG-spiked effluent from four wastewater treatment plants (WWTPs). The mecA-specific nanosensors showed stability in environmental conditions and in high ionic strength ([MgCl₂]<50mM), and high selectivity against mismatched targets. Spectrophotometric detection was reproducible with an LOD of 70pM (≈4×10⁷genes/μL), even in the presence of interferences associated with non-target genomic DNA and complex WWTP effluent. This contribution supports the environmental applicability of a new line of cost-effective, field-deployable tools needed for wide-scale biocontaminant monitoring.