Intermittent Carriers Research Articles

Nasal Staphylococcus aureus Carriage and Antimicrobial Resistance Profiles Among Community-Dwelling Adults in Jiangsu, China.

Persistent nasal carriage has beenassociated with Staphylococcus aureus infection. Previous S.aureus studies in Asia have primarily focused on clinical patients, providing limited information on persistent nasal carriage among the general adult population. This study examined 143healthy adults in a community in Jiangsu, China. Nasal swab samples were collected 10 times. The colonization status was identified using SPA typing. We also determined antimicrobial susceptibility, genotype, and genomic characteristics of S.aureus. The prevalence ofS.aureusnasal carriage among the community individuals was on average 16.78%. The carriage rates of methicillin-resistant S.aureus and multidrug-resistant S.aureus were 6.29% and 7.69%, respectively. We identified 8.39% persistent carriers, 39.16% intermittent carriers, and 52.45% noncarriers. Furthermore, family members displayed concordance in terms of genotype and genomic characteristics. Persistent nasal sampling captured intermittent carriers that were missed during short-term sampling, thus highlighting the necessity for regular community testing. SPA typing can serve as a rapid method for determining S.aureus colonization. The potential for intrafamilial transmission of S.aureus is evident, with persistent carriers being the most probable source of infection.

Herbal Bioactive Compounds for Skin Infections and Inflammatory Conditions

Skin microbiota is an integral part of the human immune system. Staphylococcus aureus is one of the essential components of the normal flora. Approximately 20–30% of healthy individuals are persistently colonized with S. aureus, whereas the remainders are considered low-level intermittent carriers. Despite these natural aspects of existence, S. aureus can be a major opportunistic human pathogen. This versatile microorganism can infect a variety of anatomical sites, causing a broad spectrum of pathologies ranging from superficial to invasive infections. It developed a variety of strategies to adopt to a changing microenvironment. This attributed to the emergence of resistance to antibiotics of different classes during the past six decades. Methicillin-resistant S. aureus (MRSA) was originally confined to health-care settings (health-care-associated MRSA). Later on, community-acquired MRSA was identified as another source of infections. Recent figures indicate that MRSA strains have been associated with approximately 75% of all S. aureus infections worldwide. Several guidelines have been published to establish an adequate treatment of skin and soft tissue infections (SSTIs) caused by MRSA strains. In the first part of this review, we focus on current treatment guidelines with a focus on medical drug therapy, but drug therapy has its own limitations. Recently, the interest in herbal remedies has greatly increased. There is growing evidence of antimicrobial activity of medicinal plants and their extracts. The second part of this review is dedicated to herbal compounds to circumvent antibiotic resistance. Herbal compounds may potentiate the action of antibiotics and restore the activities of antibacterial agents against which S. aureus has developed a drug resistance. Part 2 focuses on the role of S. aureus in pathology of the two major inflammatory skin diseases, i.e., atopic dermatitis (AD) and psoriasis. Finally, Part 3 provides an overview on natural compounds with antimicrobial activity against S. aureus and possible use in the treatment of SSTIs,

Prevention of surgical site infections: a personal odyssey

Prevention of surgical site infections: a personal odyssey

MRSA carriage among healthcare workers in a Vietnamese intensive care unit: a prospective cohort study.

Background: Little is known about the magnitude and patterns of methicillin-resistant Staphylococcus aureus (MRSA) carriage among intensive care unit (ICU) healthcare workers (HCWs), especially in lower-middle-income countries like Vietnam. Materials and methods: A prospective cohort study was conducted on HCWs working in the adult ICU of the Hospital for Tropical Diseases in Vietnam between October 28 and December 20, 2019. These HCWs included physicians, nurses, and nursing assistants who were responsible for all essential medical activities and basic patient care. A questionnaire was used to collect participants’ information, including age, sex, profession, ICU working time, and underlying diseases. Hand and nasal swabs were collected weekly for 8 consecutive weeks for MRSA screening. Staphylococcal isolates were checked for catalase and coagulase and, for methicillin resistance using cefoxitin disk diffusion, then rechecked on the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Results: Among 55 HCWs, 16 (29.1%) carried MRSA in their noses or hands. MRSA intermittent hand carriage was documented in 2 (3.6%) HCWs. Among 53 HCWs undertaking nasal swabs, 13 (24.5%) were MRSA persistent and 3 (5.6%) were intermittent carriers. The MRSA carriage rate was highest among nursing assistants (50%, 4/8). More HCWs with underlying diseases were found to be MRSA carriers (31.8%, 7/22) compared with those without comorbidities (27.3%, 9/33). Conclusion: MRSA carriage among HCWs is not rare. The findings highlight an urgent need to review and update the local infection prevention and control measures to prevent MRSA transmission from HCWs to patients.

Are Staphylococcus aureus Carrier Types Evidence of Population Heterogeneity?

Asymptomatic colonization by Staphylococcus aureus is a precursor for infection, so identifying the mode and source of transmission which leads to colonization could help in targeting interventions. Longitudinal studies have shown that some people are persistently colonized for years, while others seem to carry S. aureus for weeks or less, and conventional wisdom attributes this disparity to an underlying risk factor in the persistently colonized. We analyze published data with mathematical models of acquisition and carriage to compare this hypothesis with alternatives. The null model assumed a homogeneous population and still produced highly variable colonization durations (mean = 101.7 weeks; 5th percentile, 5.2 weeks; 95th percentile, 304.7 weeks). Simulations showed that this inherent variability, combined with censoring in longitudinal cohort studies, is sufficient to produce the appearance of "persistent carriers," "intermittent carriers," and "noncarriers" in data. Our estimates for colonization duration exhibited sensitivity to the assumption that false-positive test results can occur despite being rare, but our model-based approach simultaneously estimates specificity and sensitivity along with epidemiologic parameters. Our results show it is plausible that S. aureus colonizes people indiscriminately, and improved understanding of the types of exposures which result in colonization is essential.

Worsening Glycemia Increases the Odds of Intermittent but Not Persistent Staphylococcus aureus Nasal Carriage in Two Cohorts of Mexican American Adults.

ABSTRACTNumerous host and environmental factors contribute to persistent and intermittent nasal Staphylococcus aureus carriage in humans. The effects of worsening glycemia on the odds of S. aureus intermittent and persistent nasal carriage was established in two cohorts from an adult Mexican American population living in Starr County, Texas. The anterior nares were sampled at two time points and the presence of S. aureus determined by laboratory culture and spa-typing. Persistent carriers were defined by the presence of S. aureus of the same spa-type at both time points, intermittent carriers were S. aureus-positive for 1 of 2 swabs, and noncarriers were negative for S. aureus at both time points. Diabetes status was obtained through personal interview and physical examination that included a blood draw for the determination of percent glycated hemoglobin A1c (%HbA1c), fasting plasma glucose, and other blood chemistry values. Using logistic regression and general estimating equations, the odds of persistent and intermittent nasal carriage compared to noncarriers across the glycemic spectrum was determined controlling for covariates. Increasing fasting plasma glucose and %HbA1c in the primary and replication cohort, respectively, were significantly associated with increasing odds of S. aureus intermittent, but not persistent nasal carriage. These data suggest that increasing dysglycemia is a risk factor for intermittent S. aureus nasal carriage potentially placing those with poorly controlled diabetes at an increased risk of acquiring an S. aureus infection.IMPORTANCE Factors affecting nasal S. aureus colonization have been studied primarily in the context of persistent carriage. In contrast, few studies have examined factors affecting intermittent nasal carriage with this pathogen. This study demonstrates that the odds of intermittent but not persistent nasal carriage of S. aureus significantly increases with worsening measures of dysglycemia. This is important in the context of poorly controlled diabetes since the risk of becoming colonized with one of the primary organisms associated with diabetic foot infections can lead to increased morbidity and mortality.

Absence of methicillin-resistant Staphylococcus aureus colonization among immunocompetent healthy adults: Insights from a longitudinal study.

Methicillin-resistant Staphylococcus aureus (MRSA) has long been known as a major cause of hospital-acquired (HA-MRSA) infections worldwide. For the past twenty years, an increasing number of studies have described its emergence in the community as well. In Portugal, a country with a high-prevalence of HA-MRSA, there are only limited data available on the epidemiology of MRSA in the community. We studied the prevalence of S. aureus and MRSA colonization among healthy adults in Portugal. Between February 2015 and December 2016, a longitudinal study was conducted in which 87 adults aged 25–50 years old were followed for six months. For each participant nasopharyngeal, oropharyngeal and saliva samples were obtained monthly and, in some cases, weekly. A total of 1,578 samples (n = 526 for each sampling site) were examined for the presence of S. aureus and MRSA by classical culture-based methods. Fifty-seven adults (65.5%) carried S. aureus at least once during the six months period of the study: 19.5% were persistent S. aureus carriers and 46.0% were intermittent carriers. Carriage rates per sampling site were 20.5% in nasopharynx, 18.3% in oropharynx, and 13.5% in saliva. Simultaneous screening of the three sampling sites increased detection of S. aureus, which overall occurred in 34.4% of the 526 sampling time-points. No MRSA were isolated. In conclusion, this study adds novel information about the MRSA scenario in the Portuguese community. Our results indicate that, in Portugal, MRSA does not seem to circulate among healthy adults without risk factors and therefore this age group does not constitute, at the current time, a reservoir of MRSA in the community.

Is increased Staphylococcus aureus colonization during military service caused by specific genotypes? Molecular examination of long-term carriage in a prospective cohort study.

A 22% increase in Staphylococcus aureus colonization was observed in Norwegian recruits during first year of military service. The aim was to determine whether specific genotypes caused the increase and to examine carriage status based on genotyping. Characterization of S. aureus from nose, throat and perineum sampled at enrolment and discharge included spa typing, MLVA, detection of PVL genes and antimicrobial susceptibility testing. spa typing demonstrated high and stable genetic diversity. The three most frequent spa types were found in 15% of recruits at enrolment and in 29% at discharge. Only t084 increased significantly (p=0.02). Subtyping revealed that t084, t065 and t002 consisted of 13, 6 and 11 different MLVA types, respectively, at discharge. The military cohort (n=265) consisted of S.aureus carriers of identical genotype (n=99, 38%), carriers of non-identical genotype (n=52, 20%), intermittent carriers (n=86, 33%) and non-carriers (n=27, 10%). Carrier status was indefinable for one recruit due to unavailable isolates for genotyping. Antibiotic resistance towards erythromycin, fusidic acid and clindamycin increased significantly and above national surveillance levels. The observed increase in S.aureus colonization during military service was caused by many different genotypes implying many transmission routes. Genotype did not correlate with colonization niche or carriage status.

865. Methicillin-resistant Staphylococcus aureus (MRSA) prevalence among healthcare workers (HCW) in contact tracings in a Dutch teaching hospital, 2010-2018

BackgroundIn The Netherlands, the national guidelines on MRSA prevention and control advocate screening of HCW after unprotected exposure to MRSA carriers. Although this strategy at large is successful, contact tracing of staff is a time consuming and costly component. We evaluated our contact tracing policy for HCW over the years 2010 – 2018.MRSA prevalence among samples in contact tracing MethodsA retrospective, observational study was performed in a Dutch teaching hospital. All HCW who had unprotected contact with an MRSA carrier were included in contact tracing. When there had been a long period of unprotected admission prior to an MRSA finding, or when the index case was a HCW, than the entire (nursing) team was tested. All samples of HCWs who were tested for MRSA carriage as part of contact tracing from 2010 until 2018 were included. A pooled nose, throat and perineum swab was collected using the eSwab medium (Copan) and inoculated on chromID MRSA agar plates (bioMérieux) after enrichment in a broth.ResultsIn total, we included 8,849 samples (range: 677 – 1,448 samples per year) from a total of 287 contact tracings (range: 26 – 55 contact tracings per year). Thirty two HCWs were colonized with MRSA (0.36%; 95%CI 0.26 – 0.51). None of them developed a clinical infection.Eight HCWs (0.10%; 95%CI 0.05% – 0.19%) were colonized with the same MLVA type as the index case, and were detected in 6/287 contact tracings (2%). In 4/8 of these cases, a positive HCW was the index for undertaking contact tracing. In 3/8 cases it was clear that the HCW who was identified in the contact tracing was the source of the outbreak and was the cause of invasive MRSA infections in patients.Notably, a different MLVA type as the index case was found in 24 HCWs (0,27%; 95%CI 0,18 – 0,40) of which 7/24 HCW (29,2%) were intermittent carriers.ConclusionThis study revealed a sustained low MRSA prevalence among samples in contact tracing of healthcare workers, over nine years. Furthermore, it shows that when MRSA contact tracing is performed according to the national guideline only 1 out 1000 samples results in a secondary case. This is similar to the population carriage rate of MRSA in The Netherlands. More frequently, an unrelated strain is found. These findings raise question marks regarding the efficacy of the current strategy to perform contact tracing after unprotected exposure.Disclosures All Authors: No reported disclosures

A longitudinal study shows intermittent colonization by Staphylococcus aureus with a high genetic diversity in hemodialysis patients

Staphylococcus aureus colonization increases the risk of invasive infections in different groups of patients. We analyzed the dynamics and factors associated with S. aureus colonization in hemodialysis patients. A longitudinal study was conducted at a dialysis center associated with a tertiary health care institution. S. aureus colonization was assessed three times in nostrils and on the skin and was classified as absent, intermittent or persistent. The molecular analysis included pulsed-field gel electrophoresis (PFGE) and spa-typing. Clonal complex was inferred from spa-typing. A model of generalized estimating equations was performed to determine the factors associated with colonization. A total of 210 patients were included. Colonization by methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) isolates was 29.1 % vs. 4.8 %, 29.2 % vs. 6.7 % and 24.1 % vs. 7.1 % in the first, second and third screenings respectively. Most of the colonized patients were intermittent carriers (77.8 %, n = 63). PFGE and spa-typing revealed a high genetic diversity. One third (33.3 %) of the carriers classified as persistent had different clones during follow-up. Clonal complex 8 was frequent among MSSA (28 %) and MRSA (59 %) isolates. Current smoking (OR:7.22, 95 %CI 2.24–23.27), Charlson index (OR:1.22, 95 %CI 1.03–1.43) and previous infection by S. aureus (OR:2.41; 95 %CI:1.09−5.30) were associated with colonization by this microorganism. Colonization increased the risk of bacteremia (HR = 4.9; 95 % CI: 1.9–12.9). In conclusion, the colonization by S. aureus in hemodialysis patients changes over time and acquisition of new clones is a frequent event. These results evidence that patients are repeatedly recolonizing from hospitals, dialysis units and their homes. On the other hand, factors not associated with healthcare, as smoking, can increase the risk of colonization.

High intermittent colonization by diverse clones of β-lactam-resistant Gram-negative bacilli suggests an excessive antibiotic use and different sources of transmission in haemodialysis patients

The spread of β-lactam-resistant Gram-negative bacilli (GNB) is a topic of worldwide concern; however, knowledge about colonization by these bacteria in haemodialysis patients is limited. To analyse the dynamics and factors associated with colonization by β-lactam-resistant GNB in a dialysis centre. A longitudinal study was conducted. Stool samples were collected for each patient to evaluate extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing Gram-negative bacilli. Colonization screens were performed at three time-points and then classified as absent, intermittent, or persistent. Molecular typing included enterobacterial repetitive intergenic consensus (ERIC)-polymerase chain reaction, pulsed-field gel electrophoresis (PFGE), and multi-locus sequence typing (MLST). Clinical information was obtained from medical records and personal interview. A generalized estimating equations model was performed to determinate factors associated with the colonization. A total of 210 patients were included. ESBL-producing and carbapenem-resistant GNB colonization reached 41.2% and 11.5%, respectively. Most patients were intermittent carriers with frequencies of 73.9% and 92.95% for each bacteria group. The most frequent ESBL was CTX-M-G1, while the most common carbapenemase was KPC. ERIC-PCR and PFGE revealed high genetic diversity among strains and the Escherichia coli clone ST131 was the most important by MLST. Fluoroquinolone use (odds ratio: 3.13; 95% confidence interval: 1.03-9.44; P [cap]=0.043) and chronic obstructive lung disease (odds ratio: 3.53; 1.42-8.74; P=0.006) were associated with ESBL-producing GNB colonization. Our findings indicate a high intermittent colonization by diverse clones of β-lactam-resistant GNB in haemodialysis patients. It suggests excessive antibiotic pressure that favours the acquisition of bacteria with diverse genetic profiles and different transmission sources.

Methicillin-Resistant Staphylococcus aureus Prevalence Among Healthcare Workers in Contact Tracings in a Dutch Hospital

Background: In The Netherlands, the national guidelines on Methicillin-Resistant Staphylococcus aureus (MRSA) prevention and control advocate screening of healthcare workers (HCWs) after unprotected exposure to MRSA carriers. Although this strategy is largely successful, contact tracing of staff is a time-consuming and costly component. We evaluated our contact tracing policy for HCWs over the years 2010–2018. Methods: A retrospective, observational study was performed in a Dutch teaching hospital. All HCWs who had unprotected contact with an MRSA carrier were included in contact tracing. When there had been a long period of unprotected admission prior to an MRSA finding, or when the index case was an HCW, the entire (nursing) team was tested. All samples of HCWs who were tested for MRSA carriage as part of contact tracing from 2010 until 2018 were included. A pooled nose, throat, and perineum swab was collected using the eSwab medium (Copan) and inoculated on chromID MRSA agar plates (bioMérieux) after enrichment in a broth. Molecular typing was performed using multiple-locus variable number of tandem repeat analysis (MLVA). Results: In total, we included 8,849 samples (range, 677–1,448 samples per year) from 287 contact tracings (range, 26–55 contact tracings per year). Overall, 32 HCWs were colonized with MRSA (0.36%; 95% CI, 0.26%–0.51%). None of them developed a clinical infection. Moreover, 8 HCWs (0.10%; 95% CI, 0.05%–0.19%) were colonized with the same MLVA type as the index case and were detected in 6 of 287 contact tracings (2%). In 4 of 8 of these cases, a positive HCW was the index for undertaking contact tracing. In 3 of 8 cases, it was clear that the HCW who was identified in the contact tracing was the source of the outbreak and was the cause of invasive MRSA infections in patients. Notably, a different MLVA type as the index case was found in 24 HCWs (0.27%; 95% CI, 0.18%–0.40%) of whom 7 of 24 HCWs (29.2%) were intermittent carriers. Conclusions: This study revealed a sustained low MRSA prevalence among samples in contact tracing of HCWs over 9 years. Furthermore, it shows that when MRSA contact tracing is performed according to the national guideline, only 1 of 1,000 samples results in a secondary case. This is similar to the population carriage rate of MRSA in The Netherlands. More frequently, an unrelated strain is found. These findings raise questions regarding the efficacy of the current strategy to perform contact tracing after unprotected exposure.Funding: NoneDisclosures: None

Dynamics of Pneumococcal Carriage in Adults: A New Look at an Old Paradigm

Limited information is available on pneumococcal colonization among adults. We studied pneumococcal carriage dynamics in healthy adults using high-sensitivity approaches. Eighty-seven adults (25-50 years old) were followed for 6 months in Portugal. Nasopharyngeal, oropharyngeal, and saliva samples were obtained monthly; pneumococcal carriers were also sampled weekly. Carriage was investigated by quantitative polymerase chain reaction (targeting lytA and piaB) and culture. Positive samples were serotyped. Approximately 20% of the adults were intermittent carriers; 10% were persistent carriers (>4 months). Pneumococcal acquisition and clearance rates were 16.5 (95% confidence interval [CI], 11.2-24.2) and 95.9 (95% CI, 62.3-145.0) cases/1000 person-weeks, respectively. Living with children increased pneumococcal acquisition (hazard ratio, 9.7 [95% CI, 2.6-20.5]; P < .001). Median duration of carriage was 7 weeks and did not depend on regular contact with children. The pneumococcal carrier state in healthy adults is more dynamic than generally assumed: Acquisition is frequent and duration of carriage is often long. This suggests that some adults may act as reservoirs of pneumococci and hence, depending on the social structure of a community, the magnitude of herd effects potentially attainable through children vaccination may vary. These findings are important when designing strategies to prevent pneumococcal disease in adults.

Detection of Inducible clindamycin resistance in nasal carriers of Staphylococcus aureus among healthcare workers

Staphylococcus aureus () is recognized as one of the most common microrganisms causing nosocomial and community-acquired infections. Nasal carriage of Staphylococcus aureus is becoming an increasing problem among healthcare workers and in the healthy community individuals. General populations with persistent Staphylococcus aureus nasal carriage rates at 10% to 20%, and up to 50% are intermittent carriers. Furthermore, carrier levels of 25% have been reported among healthcare workers(HCW’s). Strains with inducible clindamycin resistance (ICR) are difficult to detect in the routine laboratory as they appear to be resistant to erythromycin and sensitive to clindamycin in vitro when not placed adjacent to each other. In such cases, in vivo treatment with clindamycin may select constitutive erm mutants leading to clinical therapeutic failure. 100 nasal swabs samples were collected during January 2019 to November 2019. Isolates were identified using standard microbioloical procedures and MRSA determined by the disk diffusion method. The D-test was performed for detection of Inducible clindamycin resistance isolates with Clinical Laboratory Standard Institute guidelines.: Out of 18 isolated, 33.3 were MRSA. Of 18 isolates tested for ICR by D-test, 6 (33.3%) yielded inducible resistance. Inducible clindamycin resistance was found to be significantly higher among MRSA than MSSA isolates. Beside personal hygiene practices of healthcare workers, regular implementation of infection control practices, including screening of nasal carriages and microbial flora in our hospital are necessary to prevent spread of MRSA. It is also advisable to perform routine nasal decolonization of healthcare workers using mupirocin ointment to prevent transmission of these organisms.

Duration of carriage of multidrug resistant Enterobacterales in discharged hospital and general practice patients and factors associated with clearance

SummaryObjectivesDutch guidelines recommend contact precautions in patients with multidrug resistant microorganisms cultured during the previous 12 months. To evaluate this policy, duration of carriage of multidrug resistant Enterobacterales was assessed among discharged hospital patients and patients attending their general practitioner (GP). Additionally, we assessed factors associated with clearance.MethodsFrom January 2013 until May 2016, rectal or faecal samples accompanied by questionnaires on patient characteristics were obtained at time of study inclusion and 3, 6 and 12 months later, in 72 patients with multidrug resistant Enterobacterales. Clearance was defined as one or more negative cultures without a subsequent positive culture at 12 months after study inclusion. The percentage of clearance, intermittent carriage and persistence was determined and associated factors were assessed by logistic regression analysis.ResultsClearance was found in 31 patients (43.1% [95%CI: 32.3–54.6]) of which 23 patients had two or more subsequent negative cultures. Twelve patients were classified as intermittent carriers (16.7% [95%CI: 9.8–26.9]) and 29 patients (40.3% [95% CI: 29.7–51.8]) as persistent carriers. Of the intermittent carriers, the majority (n=9) had two negative cultures during the study period. There was no difference in clearance between discharged hospitalized patients and GP patients. The only factor associated with clearance at 12 months in both univariable and multivariable analyses was not traveling to a foreign country (OR=3.5 [95%CI: 1.0–12.4]).ConclusionActive screening for clearance of multidrug resistant Enterobacterales in patients within the health care setting is probably not beneficial due to high levels of intermittent and persistent carriage.

Staphylococcus aureus nasal carriage and microbiome composition among medical students from Colombia: a cross-sectional study

Background: The anterior nares are the main ecological niche for Staphylococcus aureus, an important commensal and opportunistic pathogen. Medical students are frequently colonized by a variety of pathogens. Microbial interactions in the human nose can prevent or favor colonization by pathogens, and individuals colonized by pathogens have increased risk of infection and are the source of transmission to other community members or susceptible individuals. According to recent studies, the microbiome from several anatomic areas of healthy individuals varies across different ethnicities. Although previous studies analyzed the nasal microbiome in association with S. aureus carriage, those studies did not provide information regarding ethnicity of participants. Our aim was to assess S. aureus nasal carriage patterns and prevalence among medical students from Colombia, a country of Hispanic origin, and to investigate possible associations of colonization and nasal microbiome composition (bacterial and fungal) in a subgroup of students with known S. aureus carriage patterns. Methods: Nasal swabs from second-year medical students were used to determine prevalence and patterns of S. aureus nasal carriage. Based on microbiological results, we assigned participants into one of three patterns of S. aureus colonization: persistent, intermittent, and non-carrier. Then, we evaluated the composition of nasal microbial communities (bacterial and fungal) in 5 individuals from each carriage category using 16S rRNA and Internal-Transcribed-Spacer sequencing. Results: Prevalence of S. aureus nasal carriage among medical students was 28%. Carriage of methicillin-resistant strains was 8.4% and of methicillin-sensitive strains was 19.6%. We identified 19.6% persistent carriers, 17.5% intermittent carriers, and 62.9% non-carriers. Conclusions: Analysis of nasal microbiome found that bacterial and fungal diversity was higher in individuals colonized by S. aureus than in non-carriers; however, the difference among the three groups was non-significant. We confirmed that fungi were present within the healthy anterior nares at substantial biomass and richness.

Staphylococcus aureus nasal carriage and microbiome composition among medical students from Colombia: a cross-sectional study

Background: The anterior nares are the main ecological niche for Staphylococcus aureus, an important commensal and opportunistic pathogen. Medical students are frequently colonized by a variety of pathogens. Microbial interactions in the human nose can prevent or favor colonization by pathogens, and individuals colonized by pathogens have increased risk of infection and are the source of transmission to other community members or susceptible individuals. According to recent studies, the microbiome from several anatomic areas of healthy individuals varies across different ethnicities. Although previous studies analyzed the nasal microbiome in association with S. aureus carriage, those studies did not provide information regarding ethnicity of participants. Our aim was to assess S. aureus nasal carriage patterns and prevalence among medical students from Colombia, a country of Hispanic origin, and to investigate possible associations of colonization and nasal microbiome composition (bacterial and fungal) in a subgroup of students with known S. aureus carriage patterns. Methods: Nasal swabs from second-year medical students were used to determine prevalence and patterns of S. aureus nasal carriage. Based on microbiological results, we assigned participants into one of three patterns of S. aureus colonization: persistent, intermittent, and non-carrier. Then, we evaluated the composition of nasal microbial communities (bacterial and fungal) in 5 individuals from each carriage category using 16S rRNA and Internal-Transcribed-Spacer sequencing. Results: Prevalence of S. aureus nasal carriage among medical students was 28%. Carriage of methicillin-resistant strains was 8.4% and of methicillin-sensitive strains was 19.6%. We identified 19.6% persistent carriers, 17.5% intermittent carriers, and 62.9% non-carriers. Conclusions: Analysis of nasal microbiome found that bacterial and fungal diversity was higher in individuals colonized by S. aureus than in non-carriers; however, the difference among the three groups was non-significant. We confirmed that fungi were present within the healthy anterior nares at substantial biomass and richness.

Staphylococcus aureus nasal carriage and microbiome composition among medical students from Colombia: a cross-sectional study.

Background: The anterior nares are the main ecological niche for Staphylococcus aureus, an important commensal and opportunistic pathogen. Medical students are frequently colonized by a variety of pathogens. Microbial interactions in the human nose can prevent or favor colonization by pathogens, and individuals colonized by pathogens have increased risk of infection and are the source of transmission to other community members or susceptible individuals. According to recent studies, the microbiome from several anatomic areas of healthy individuals varies across different ethnicities. Although previous studies analyzed the nasal microbiome in association with S. aureus carriage, those studies did not provide information regarding ethnicity of participants. Our aim was to assess S. aureus nasal carriage patterns and prevalence among medical students from Colombia, a country of Hispanic origin, and to investigate possible associations of colonization and nasal microbiome composition (bacterial and fungal) in a subgroup of students with known S. aureus carriage patterns. Methods: Nasal swabs from second-year medical students were used to determine prevalence and patterns of S. aureus nasal carriage. Based on microbiological results, we assigned participants into one of three patterns of S. aureus colonization: persistent, intermittent, and non-carrier. Then, we evaluated the composition of nasal microbial communities (bacterial and fungal) in 5 individuals from each carriage category using 16S rRNA and Internal-Transcribed-Spacer sequencing. Results: Prevalence of S. aureus nasal carriage among medical students was 28%. Carriage of methicillin-resistant strains was 8.4% and of methicillin-sensitive strains was 19.6%. We identified 19.6% persistent carriers, 17.5% intermittent carriers, and 62.9% non-carriers. Conclusions: Analysis of nasal microbiome found that bacterial and fungal diversity was higher in individuals colonized by S. aureus than in non-carriers; however, the difference among the three groups was non-significant. We confirmed that fungi were present within the healthy anterior nares at substantial biomass and richness.

Efficacy and acceptability of treatment to eradicate nasal Staphylococcus aureus carriage among haemodialysis patients.

For patients requiring haemodialysis, the risk of Staphylococcus aureus disease is higher in those colonized and persists while the person requires haemodialysis, necessitating frequent decolonization. However, the duration of successful decolonization is not known. This study aimed to determine the duration of efficacy of decolonization in intermittent and persistent S. aureus carriers requiring haemodialysis using two decolonization strategies. We screened 100 outpatients requiring haemodialysis for S. aureus carriage and then decolonized 14 intermittent carriers and 18 persistent carriers. Participants were invited to undertake two decolonization attempts, using systemic or topical antibiotics 12 weeks apart. Nasal swabs were taken weekly to determine the duration of successful decolonization. Decolonization was successful in 24/32 (75%) participants and the median duration of decolonization was 35 days (95% confidence interval (CI) 11-59). The median duration of S. aureus decolonization was significantly shorter for persistent carriers (19 days, 95% CI 13-25 days) in comparison with intermittent carriers (70 days, 95% CI 61-79 days; P < 0.01). 28/52 (54%) post-decolonization surveys indicated that they would use the treatment again, 14/52 (27%) surveys indicated that they would not use the treatment again, and 10/52 (19%) were undecided. 16/53 (30%) decolonization attempts resulted in an adverse drug reaction. Staphylococcus aureus decolonization using topical or systemic treatments was successful for many haemodialysis patients, and provided a month free of S. aureus colonization. Although decolonization treatment provided a shorter duration of success for persistent carriers in comparison with intermittent carriers, persistent carriers are likely to gain the most from effective decolonization strategies.

Factors Associated with Methicillin Resistant Staphylococcus aureus Carriage

S. aureus is a common commensal of the skin and mucosal membranes of humans, with estimates of 20% (range from 12% to 30%) of healthy people are persistent S. aureus nasal carriers, 30% (range from 16% to 70%) are intermittent carriers, and 50% (range from 16% to 69%) are non-carriers. The aim of this article is to explore the factors associated with Methicillin Resistant Staphylococcus Aureus carriage among food handlers. Across sectional study was done to involve 200 persons who are handling foods in 40 restaurants in Duhok city in the study. Methicillin Resistant Staphylococcus Aureus was detect among 27% of studied population. Methicillin Resistant Staphylococcus Aureus carrier rate showed a significant association with skin and soft tissue infections, health facilities visits and certain jobs of food handlers. Age, duration of work in the restaurants, personal protective measures and antibiotic use showed no significant association with the prevalence of MRSA. Methicillin Resistant Staphylococcus Aureus carrier rate was higher among food handlers working in popular restaurants when compared to other restaurants. Ongoing screening of all persons who handled foods is crucial to detect and treat those are MRSA carrier as one of major public health issues