Nasal Carriage Research Articles

Identification of Nasal Carriage of Staphylococcus aureus among Nursing Students during Curricular Clinical Internships: An Observational Study

Staphylococcus aureus is considered one of the most frequently isolated bacteria in the community and in the hospital environment, being associated with several infections. Healthcare professionals represent a group vulnerable to Staphylococcus aureus and MRSA colonization, therefore being potential disseminators of these microorganisms during their care activities. The aim of this study was to evaluate the dynamics of S. aureus and MRSA nasal colonization among nursing students over the four years of university attendance, including pre-clinical exposure and at different moments during clinical rotations. Samples were collected from students from the 1st, 2nd, 3rd and 4th year. The study identified 55.9% MSSA positive samples and 31.4% MRSA positive samples from the total studied population. Simultaneous carriage of MRSA and MSSA was observed in students from all years of the nursing degree, but a highest MSSA colonization (61.5%) was linked to a lower MRSA colonization (30.8%). MRSA colonization seems to be dependent on the type of clinical internship, since the group attending internship in emergency rooms and surgery wards presented a significant increase in the amount of MRSA samples. Nursing students should be educated on the risks involved in carrying S. aureus and MRSA and informed about infection control measures.

Implementation of a surgical site infection prevention bundle: Patient adherence and experience.

We evaluated barriers and facilitators to patient adherence with a bundled intervention including chlorhexidine gluconate (CHG) bathing and decolonizing Staphylococcus aureus nasal carriers in a real-world setting. Survey data identified 85.5% adherence with home use of CHG as directed and 52.9% adherence with home use of mupirocin as directed.

887. Implementation of a Surgical Site Infection (SSI) Prevention Bundle: Patient Compliance and Experience

BackgroundAn evidence-based preoperative bundle including chlorhexidine gluconate (CHG) bathing, screening for S. aureus nasal carriage and decolonizing carriers with mupirocin was the standard of care for patients having total joint arthroplasty (TJA) at a VA medical center. We aimed to assess patient compliance with mupirocin and CHG, and characterize patient perceptions of barriers and facilitators to compliance.Compliance with CHG Bathing & Mupirocin By Methicillin-resistant S. aureus (MRSA) or Methicillin-susceptible S. aureus (MSSA) Colonization Status MethodsThe bundle for S. aureus colonized patients having TJA included nasal mupirocin ointment twice daily and daily CHG bathing for 5 days before surgery. The bundle for non-carriers included CHG bathing the day before and the morning of surgery. From 7/2018-10/2019, inpatients completed a 31-item survey following their TJA.Results73 patients completed the survey (~29% of the TJA population). 17 patients (23%) carried S. aureus & 56 patients (77%) were non-carriers. Patients reported high compliance with home use of CHG for the full number of days directed (88% when prescribed for 2 days; 71% when prescribed for 5 days; overall 85% used as prescribed; Figure). 7 (10%) patients reported CHG side effects, including burning or itchy/dry skin. 99% of patients reported willingness to use the CHG before a future surgery. Compliance with home use of mupirocin was lower (53% used as prescribed). Reported side effects included stinging, itching or dryness (N=2, 12%), unpleasant taste (N=2, 12%) & runny or stuffy nose (N=3, 18%). 100% of patients reported willingness to use mupirocin before a future surgery. Barriers to patient compliance with the bundle included forgetfulness and difficulty bathing daily. Facilitators to patient compliance included high facility compliance with S. aureus screening (100% patients reported), patient education regarding CHG and mupirocin use (95% patients recalled), and access to prescribed medications (100% patients received). Most patients (93%) reported no financial burden for mupirocin and 95% of patients reported no financial burden for CHG.ConclusionPatients reported high willingness to use the prevention bundle, yet mupirocin compliance was sub-optimal. Replacing patient-applied home mupirocin with nurse-applied day-of-surgery decolonization should be assessed in order to facilitate increased compliance.Disclosures All Authors: No reported disclosures

Staphylococcus aureus nasal colonization among health care workers at an Egyptian tertiary care hospital

Background: Staphylococcus aureus (S. aureus) colonization in health care workers (HCWs) is a major factor of nosocomial infections. Methicillin resistant S. aureus (MRSA) is incriminated in hospital-acquired infection. Objectives: To evaluate the colonization rates of nasal carriage of S. aureus and MRSA among HCWs at Al-Ahrar Teaching Hospital. Methods: We recruited 163 HCWs in a cross section study. S. aureus was identified phenotypically by coagulase, with DNase tests and genotypically by nuc gene detection. Antibiotics sensitivity was tested by disk diffusion. PCR for mecA was done to confirm MRSA identification. Results: Forty-eight S. aureus strain were isolated. The frequency of nasal colonization of S. aureus in HCWs was 29.44% (48/163), the frequency of MRSA isolates in HCWs was 27.6% (45/163), and frequency of MRSA isolates among S.aureus isolates was 93.8% (45/48). Prior infection (last 3 months) and living in crowded places increased significantly risk of MRSA nasal carriage by 29.3 and 79.59 folds respectively Conclusion: We demonstrated high rates of nasal carriage of S. aureus and MRSA among HCWs. Prior infection and living in crowded places were risk factors for methicillin resistance among isolated S.aureus stains.

Circulating sex-steroids and Staphylococcus aureus nasal carriage in a general female population

ObjectiveStaphylococcus aureus is a major human pathogen, and nasal carriers have an increased risk for infection and disease. The exploration of host determinants for nasal carriage is relevant to decrease infection burden. Former studies demonstrate lower carriage prevalence in women and among users of progestin-only contraceptives. The aim of this study was to investigate the possible associations between circulating sex-steroid hormones and nasal carriage of Staphylococcus aureus in a general population.MethodsIn the population-based sixth Tromsø study (2007–2008) nurses collected nasal swab samples from 724 women aged 30–87 not using any exogenous hormones, and 700 of the women had a repeated nasal swab taken (median interval 28 days). We analysed a panel of serum sex-steroids by liquid chromatography tandem mass spectrometry, and collected information about lifestyle, health and anthropometric measures. Multivariable logistic regression was used to study the association between circulating sex-steroids and Staphylococcus aureus carriage (one swab) and persistent carriage (two swabs), while adjusting for potential confounding factors. Women in luteal phase were excluded in the analysis of androgens.ResultsStaphylococcus aureus persistent nasal carriage prevalence was 22%. One standard deviation increase in testosterone and bioavailable testosterone was associated with lower odds of persistent nasal carriage, (OR = 0.57; 95% CI = 0.35–0.92 and OR = 0.52, 95% CI = 0.30–0.92) respectively. Analysis stratified by menopause gave similar findings. Persistent carriers had lower average levels of androstenedione and DHEA, however, not statistically significant.ConclusionThis large population-based study supports that women with lower levels of circulating testosterone may have increased probability of Staphylococcus aureus persistent carriage.

Screening for Nasal Carriage of Mupirocin Resistant Staphylococcus aureus among health care workers in a tertiary care hospital

Introduction: The aim is to isolate and to identify Staphylococcus aureus from the nasal swabs of the health care workers and screen for the mupirocin resistance among the isolated Staphylococcus strains. Materials and Methods: Present study is a prospective type of study. A total of 100 nasal swabs were collected from health care workers. All the nasal swabs were cultured on MacConkey and Blood agar. Isolated organisms were subjected for antibiotic susceptibility testing by Kirby-Bauer disk diffusion method. Results: Among the 100 nasal swabs, Staphylococcus spp. was isolated in 100 (100%) samples which comprised of 13 (13%) Staphylococcus aureus isolates and 87(87%) were Coagulase negative Staphylococcus. Of 13 Staphylococcus aureus isolates, 7 (53.84%) and 6 (46.15%) were detected as Methicillin Resistant Staphylococcus aureus and Methicillin Sensitive Staphylococcus aureus respectively. None of S.aureus isolates was resistant to mupirocin. Low level mupirocin resistant (MupL) was seen in 10 (30%) of Methicillin Resistant Coagulase negative Staphylococcus and 5 (14.7%) in Methicillin Sensitive Coagulase negative Staphylococcus isolates, respectively. High level mupirocin resistant (MupH) was seen in 4 (12%) of Methicillin Resistant Coagulase negative Staphylococcus and 4 (12%) of MRCoNS and MSCoNS isolates, respectively. Conclusion: Mupirocin is a potent antibiotic to treat the nasal carriage of S. aureus. As resistance to mupirocin both low and high level is on rise, it is a matter of great concern. Policies and guidelines should be framed to create awareness among the health care workers regarding the screening methods for the detection and treatment of nasal carriage. Keywords: MRSA- Methicillin resistant Staphylococcus aureus, MSSA- Methicillin sensitive Staphylococcus aureus, Mupirocin resistance

Prevalence of Nasal carriage of coagulase negative staphylococci and its antimicrobial susceptibility among ICU health care workers at a tertiary care hospital of Barabanki, UP

Introduction: Health care workers (HCW) including medical as well as paramedical workers are a potential source of carrier of infection for the patients admitted in different intensive care units (ICU). The anterior nares are the main reservoir of Staphylococcus although other body sites are frequently colonised with it, such as hands, skin, axillae, and intestinal tract. The body parts of health care workers as well as the equipments and accessories used by them are likely to transmit infections. Materials and Methods: A prospective study was conducted to evaluate the infections in different ICUs. A total of 288 parallel nasal and hands swabs were collected. These samples were cultured as per standard protocols and antibiotic sentivity was also carried out. For antibiotic sensitivity Kirby disc diffusion method on Mueller Hinton agar plate was used. Coagulase negative Staphylococcus was the bacteria isolated and subjected to sensitivity towards different antibiotics. Results: Of the 288 samples 90 samples (31.3%) were positive while 198 (68.7%) were negative. The distribution of the positive samples from Medical ICUs – 47 cases, Paediatric ICUs – 21 and, Surgical ICUs – 22 cases. Conclusion: Coagulase negative Staphylococci were predominantly isolated from culture and increasing antibiotic resistance is also observed. The most effective antibiotics were Tobramycin, Teicoplanin and Linezolid while Penicillin, Gentamycin and Erythromycin showed highest resistance. HCW themselves as well as the accessories used by them are an important potential source of infection for the admitted patients. Regular disinfection of these accessories should be strictly followed in each and every ICU. Keywords: Nosocomial, Cons, Healthcare workers, Nasal carrier, ICU.

Nasal Carriage by Staphylococcus aureus among Healthcare Workers and Students Attending a University Hospital in Southern Brazil: Prevalence, Phenotypic, and Molecular Characteristics.

Background Staphylococcus aureus can asymptomatically colonize the human anterior nares and skin, and nasal colonization by this bacterium represents a potential risk for development of invasive infections. The aim of this study was to determine the prevalence of S. aureus nasal carriage among healthcare workers and students attending a university hospital and to characterize the isolates phenotypically and molecularly. Methods A cross-sectional study was performed with 324 volunteers. Cultures from nasal samples were obtained and S. aureus isolates were characterized according to their antimicrobial susceptibility profile and four virulence factors-encoding genes. MRSA isolates were characterized regarding their oxacillin/cefoxitin susceptibility, SCCmec, and REP-PCR types. Potential risks for S. aureus and MRSA carriage were analyzed. Results Of 324 nasal samples, 42.9% were identified as S. aureus, of which 28.8% were MRSA. S. aureus carriers were significantly higher in males and students (OR = 2.898, 95%CI 1.553–5.410); however, no variables were associated with MRSA carriage. All isolates were susceptible to vancomycin and the highest rate of resistance was observed for penicillin (90.6%). All isolates harbored the coa gene, and 97.8%, the icaA gene; 15.8% and 6.5% were positive for tst and lukS-PV/lukF-PV genes, respectively. Among MRSA isolates, 45% carried the mecA gene but were phenotypically susceptible to oxacillin/cefoxitin; two harbored the tst and none had lukS-PV/lukF-PV genes. All MRSAs were distributed into six SCCmec types and type I (62.5%) was the most frequent. REP-PCR typing identified four main clusters among MRSA isolates. Conclusion High prevalence of healthcare workers and students were identified as nasal carriers of S. aureus exhibiting different antimicrobial resistance profiles, including mecA-positive oxacillin-susceptible S. aureus (OS-MRSA) and the presence of virulence-encoding genes. Both cohorts may represent potential sources for the emergence of a successful S. aureus strain highly adapted to the hospital environment.

Evaluation of Systemic and Mucosal Immune Responses Induced by a Nasal Powder Delivery System in Conjunction with an OVA Antigen in Cynomolgus Monkeys.

An immune response for a nasal ovalbumin (OVA) powder formulation with an applied nasal delivery platform technology, consisting of a powdery nasal carrier and a device, was evaluated in monkeys with similar upper respiratory tracts and immune systems to those of humans, in order to assess the applicability to a vaccine antigen. Nasal distribution and retention studies using a 3D nasal cavity model and manganese-enhanced MRI were conducted by administering nasal dye and manganese powder formulations with the applied technology. Systemic and mucosal immune responses for the nasal OVA powder formulation were evaluated by determining serum IgG and nasal wash IgA antibody titers. The nasal dye and manganese powder formulations showed wider distribution and longer retention time than did a nasal liquid formulation. The nasal OVA powder formulation also showed comparable and higher antigen-specific IgG antibody titer to an injection and nasal liquid formulation, respectively. Furthermore, antigen-specific IgA antibody response was detected only for the nasal OVA powder formulation. The present study suggests that the technology, originally designed for drug absorption, is promising for nasal vaccines, enabling both a mucosal immunity response as the first line of defense and systemic immunity response as a second line of defense against infection.

Colonization of the nasal airways by Staphylococcus aureus on admission to a major heart surgery operating room: A real-world experience

IntroductionNasal swab culture is used to identify Staphylococcus aureus colonization, as this is a major risk factor for surgical site infection (SSI) in patients who are going to undergo major heart surgery (MHS). We determined nasal carriage of S. aureus in patients undergoing MHS by comparing the yield of a conventional culture with that of a rapid molecular test (Xpert® SA Nasal Complete, Cepheid). MethodsFrom July 2015 to April 2017, all patients who were to undergo MHS were invited to participate in the study. We obtained two nasal cultures from each patient just before entering the operating room, independently of a previous test for the determination of nasal colonization by this microorganism performed before surgery. One swab was used for conventional culture in the microbiology laboratory, and the other was used for the rapid molecular test. We defined nasal colonization as the presence of a positive culture for S. aureus using either of the two techniques. All patients were followed up until hospital discharge or death. ResultsOverall, 57 out of 200 patients (28.5%) were colonized by S. aureus at the time of surgery. Thirty-three patients had both conventional culture- and PCR-positive results. Twenty-four patients had a negative culture and a positive PCR test. Only twenty-one percent (12/57) of colonized patients had undergone an attempt to decolonise before the surgical intervention. ConclusionA significant proportion of patients undergoing MHS are colonized by S. aureus in the nostrils on entering the operating room. New strategies to prevent SSI by this microorganism are needed. Rapid molecular tests immediately before MHS, followed by immediate decolonisation, must be evaluated.Trial Registration Clinical Trials.gov NCT02640001.

Nasal carriage of biofilm producing methicillin resistant Staphylococcus aureus among healthcare workers in a tertiary care hospital, Kathmandu, Nepal

Nasal carriage of biofilm producing methicillin resistant Staphylococcus aureus among healthcare workers in a tertiary care hospital, Kathmandu, Nepal

Nasal carriage of methicillin-resistant Staphylococcus aureus among healthcare undergraduates in Malaysia

Staphylococcus aureus is a common component of skin flora of healthy adults. However, it can cause serious infections such as bloodstream infections, pneumonia, or bone and joint infections. Methicillin-resistant Staphylococcus aureus (MRSA) is known to cause hospital- (HA-MRSA) and community-acquired (CA-MRSA) infections worldwide. Asia is reported to have highest prevalence rates of HA-MRSA and CA-MRSA. As there were very less number of epidemiological studies being done in Malaysia, this study aimed to determine the prevalence of MRSA infection among the healthcare undergraduates who will be engaging with patients soon. We analyzed nasal swabs of students from a private medical institution in Klang Valley, Malaysia. Methicillin-resistance was accessed by sensitivity to the Oxacillin and Cefoxitin disks. In a total of 151 healthcare undergraduates, 117 of them were found positive for Staphylococcus aureus. Among the latter, 21 samples (13.9%) were resistant to Oxacillin and Cefoxitin. Our data shows significant high percentage of MRSA infection and therefore prevention strategies for MRSA need to be developed for the healthcare students before they engage with patients in clinic setting. Keywords: MRSA, nasal swab, healthcare undergraduates, Oxacillin.

English

Rise of antibiotic resistant Staphylococcus aureus is a higher risk and great concern to global health. Zoonotic transfer of such strains is well documented. Present study evaluated the presence of resistant S. aureus from mastitic Nilli Ravi buffaloes and nasal carriage of milkers. Phenotypic profile of S. aureus isolates was conducted against penicillin, ampicillin, and cefoxitin. PCR analysis revealed presence of blaZ gene and mecA gene from S. aureus isolated from milk and milkers samples. Sequence and phylogenetic analysis depicts the divergence of mecA gene originated from bovine and human but for the blaZ gene, no divergence was detected. The high degree of genetic relatedness among blaZ and mecA genes in bovine and human S. aureus isolates from same farm suggests the potential transfer of antimicrobial resistance genes between buffaloes and milkers, highlighting the importance of one-health approach to promote global health

Presence of the neonatal Staphylococcus capitis outbreak clone (NRCS-A) in prosthetic joint infections

Staphylococcus capitis is a coagulase-negative staphylococcus that has been described primarily as causing bloodstream infections in neonatal intensive care units (NICUs), but has also recently been described in prosthetic joint infections (PJIs). The multidrug-resistant S. capitis subsp. urealyticus clone NRCS-A, comprising three sublineages, is prevalent in NICUs across the world, but its impact on other patient groups such as those suffering from PJIs or among adults planned for arthroplasty is unknown. Genome sequencing and subsequent analysis were performed on a Swedish collection of PJI isolates (n = 21), nasal commensals from patients planned to undergo arthroplasty (n = 20), NICU blood isolates (n = 9), operating theatre air isolates (n = 4), and reference strains (n = 2), in conjunction with an international strain collection (n = 248). The NRCS-A Outbreak sublineage containing the composite type V SCCmec-SCCcad/ars/cop element was present in PJIs across three Swedish hospitals. However, it was not found among nasal carrier strains, where the less virulent S. capitis subsp. capitis was most prevalent. The presence of the NRCS-A Outbreak clone in adult patients with PJIs demonstrates that dissemination occurs beyond NICUs. As this clone has several properties which facilitate invasive infections in patients with medical implants or immunosuppression, such as biofilm forming ability and multidrug resistance including heterogeneous glycopeptide-intermediate susceptibility, further research is needed to understand the reservoirs and distribution of this hospital-associated pathogen.

Prevalence of Methicillin Resistant Staphylococcus aureus Nasal Colonizers among Basic Science MBBS and BDS Students of Kathmandu Medical College.

Methicillin-Resistant Staphylococcus aureus exhibit multiple drug resistance phenotypes. Colonizers harboring Methicillin-Resistant Staphylococcus aureus are often associated with its outbreaks in both hospital and community settings. This study was done to determine the prevalence of nasal carriage rate of Methicillin-Resistant Staphylococcus aureus among basic science MBBS and BDS students of Kathmandu Medical College. A descriptive cross-sectional study was done in Kathmandu Medical College from March 5 to June 5 2020. Ethical clearance was obtained from the Institutional Review Committee with reference no. 040320201. A convenient sampling method was used, and the sample size was calculated with a prevalence of 50%. Two hundred students studying MBBS and BDS were enrolled. The nasal swab was collected and processed using standard microbiological methods. The data obtained were computed and analyzed using Statistical Package for Social Sciences 16.0 Version. Among 200 participants, 9 (4.5%) were found to be nasal carriers of Methicillin-Resistant Staphylococcus aureus. Colonization of anterior nares by Methicillin-Resistant Staphylococcus aureus in apparently healthy individuals is a cause of concern. Education regarding Methicillin-Resistant Staphylococcus aureus, its carrier and significance, and its screening must be included early on in MBBS and BDS.

A cross sectional study to assess nasal carriage of methicillin resistant Staphylococcus aureus in healthcare professionals in a tertiary care hospital.

To determine the nasal carriage of staphylococcus aureus and methicillin-resistant staphylococcus aureus among healthcare workers in a tertiary care setting. The cross-sectional study was conducted at the Pakistan Institute of Medical Sciences, Islamabad, Pakistan, from April to July 2018, and comprised healthcare workers at the institution. Nasal swabs were collected and cultured on Mannitol salt agar. Mannitol fermenting colonies which were gram-positive cocci, catalase-positive and coagulase-positive were identified as staphylococcus aureus. Antibiotic susceptibility test was performed by modified Kirby-Bauer disc diffusion method. Methicillin resistance was detected using cefoxitin disc diffusion method. Data was analysed using SPSS 23. Of the 210 nasal swabs, 52(24.76%) had a staphylococcus aureus growth, and of them, 15(7.1%) were methicillin-resistant. No association could be established with either any single category of healthcare worker or an inter-department variation (p>0.05). Likewise, there was no association with age, gender, duration of service, smoking, co-morbidities, use of antibiotics in the preceding six months, treating a patient with methicillin-resistant staphylococcus aureus in the preceding six months and hospitalisation in the preceding year (p>0.05). The frequency of nasal carriage of methicillin resistant staphylococcus aureus amongst healthcare workers was regardless of the nature of their professional engagement.

Distribution of Staphylococcal cassette chromosome mecA (SCCmec) types among coagulase-negative Staphylococci isolates from healthcare workers in the North-West of Iran.

Objective(s):Methicillin-resistant coagulase-negative Staphylococci (MR-CoNS) are recognized as one of the major causes of healthcare-associated infections in hospitals. The present investigation aimed to study the prevalence of Staphylococcal cassette chromosome mec (SCCmec) types, along with aminoglycoside modifying enzymes (AMEs) genes in the nasal carriage of MR-CoNS in the north-west of Iran.Materials and Methods:To assess the potential of coagulase-negative Staphylococci as hidden reservoirs for antibiotic resistance, we analyzed the antimicrobial susceptibility of MR-CoNS using the disk diffusion method. In addition, PCR and multiplex PCR assays were performed to determine the prevalence of AME encoding genes and SCCmec types in methicillin-resistant coagulase-negative Staphylococci isolates.Results:A total of 51 MR-CoNS isolates were recovered from the anterior nares of healthcare workers. The observed resistance rates to tobramycin, gentamicin, cotrimoxazole, kanamycin, erythromycin, tetracycline, and ciprofloxacin were 74.5%, 68.5%, 57%, 53%, 51%, 49%, and 8%, respectively. Of the 51 tested MR-CoNS isolates, 2(4%) were harboring SCCmec type I, four (8%) were type II, six (12%) type III, eleven (21.6%) type IVa, two (4%) type IVb, two (4%) type IVc, six (12%) type IVd, and two (4%) type V. The rates of prevalence of the aminoglycoside modifying enzyme genes were as follows: aac (6′)/aph (2′′) (28 cases, 55 %), ant (4′)-Ia (20 cases, 39%), and the aph (3´)-IIIa gene (9 cases, 17.6 %).Conclusion:Subtypes IVa and IVd were the most prevalent SCC elements, and aac (6′)/aph (2′′) was the most common AME gene detected among the MR-CoNS isolates.

Nasal carriage of highly resistant methicillin resistant Staphylococcus aureus (MRSA) strains by hospital staff in Hazara region of Pakistan.

To isolate and characterise multidrug resistant strains of Staphylococcus aureus from healthcare workers who are at potential risk of nosocomial infections. The observational, cross-sectional study was conducted from November 2014 to April 2015 at different hospitals of Haripur and Abbottabad, Pakistan, and comprised ward and operation theatre staff. The isolates were identified on the basis of microbiological and biochemical tests and further confirmed by polymerase chain reaction. Disc diffusion method was used for antibiotic sensitivity testing, and panton valentine leukocidin and methicillin resistance mecA genes were detected using polymerase chain reaction. Of 208 isolates, 108(52%) were from the ward staff and 100(48%) were from the operation theatre staff. Overall, 167(80.3%) isolates were positive for Staphylococcus aureus, and 75(36%) were methicillin-resistant Staphylococcus aureus. The number of antibiotic-resistant isolates was 75(45%) cefoxitin, 60(36%) ofloxacin, 152(91%) erythromycin, 52(31%) doxycycline, 127(76%) lincomycin, 53(32%) amoxicillin-clavulanate, 67(40%) ciprofloxacin, and 89(53%) ceftriaxone. A high number of hospital staff, including those working in operation theatres, were found to be carrying methicillin-resistant Staphylococcus aureus and multidrug resistant strains in their nasal passage that may be a source of infection to patients.

Methicillin-resistant Staphylococcus aureus nasal carriage among janitors working in hospital and non-hospital areas: a comparative cross-sectional study

BackgroundNasal colonization of Methicillin-resistant Staphylococcus aureus (MRSA) plays a key role in the epidemiology and pathogenesis of both healthcare-associated and community-acquired MRSA infections in various populations. Screening of MRSA nasal colonization is important in the prevention and control of infection and may provide useful information to guide antimicrobial therapy. This study aimed to determine nasal carriage of MRSA, its antimicrobial susceptibility pattern, and associated factors among janitors working in hospital & non-hospital areas at the University of Gondar, Northwest Ethiopia.MethodsA comparative cross-sectional study was carried out in a total of 436 study participants (221 hospital and 215 non-hospital janitors) from January to May 2019. The study participants were sampled using a simple random sampling technique. Data on socio-demographic characteristics and associated factors were collected through face to face interviews using a structured questionnaire. Nasal swabs were collected and inoculated into Mannitol salt agar. MRSA was detected using cefoxitin (30 µg) disc and an antibiotic susceptibility test was done using the disc diffusion method. Data were entered and analyzed using SPSS version 20 statistical package. P value ≤ 0.05 was considered as statistically significant.ResultsThe overall prevalence of S. aureus was 101/436 [23.2%, (95% CI: 19.3–27.8)], of which, 29.4% (65/221) were isolated from hospital and 16.7% (36/215) non-hospital janitors. The prevalence of MRSA was 4.8% (21/436) [95% CI: 3.0–6.9]; of these, 8.1% (18/221) of the isolates were from the hospital and 1.4% (3/215) non-hospital janitors, while methicillin-sensitive S. aureus (MSSA) in hospital & non-hospital janitors were 49 (22.2%) and 31 (14.4%), respectively. Among the MRSA isolates, 52.4% (11/21) were multi-drug resistant. Of these, 42.9% (9/18) were isolated from hospital and 66.7% (2/3) non-hospital janitors. Hence, nasal carriage of MRSA was significantly associated with hospitalization within the preceding year (AOR = 3.15, CI = 1.13–8.71).ConclusionThe present study revealed that high MSSA and MRSA were isolated from the hospital as compared to non-hospital janitors and high rates of antibiotics resistance were recorded in the hospital janitors. Consequently, hospitalizations were significantly associated with MRSA. Accordingly, regular screening of carriers in apparently healthy janitors is required for the prevention of nosocomial infections.

Insights into the epidemiology of methicillin-resistant coagulase-negative Staphylococci carriage in community-based drug users

BackgroundCoagulase-negative Staphylococci (CoNS) are opportunistic pathogens. Methicillin-resistant CoNS (MRCoNS) remain a major cause of nosocomial infections, but limited information is available in communities. We, therefore, aimed to investigate the epidemiology of CoNS nasal carriage, especially MRCoNS in community-based drug users. MethodsDrug users were included in the cross-sectional study from three communities in Guangzhou, China. A face-to-face questionnaire was used to collect individual information and nasal swabs were collected to identify CoNS and MRCoNS isolates. Phenotypic and genotypic characterization of MRCoNS isolates were detected by using the disk diffusion method and polymerase chain reaction assays. Factors impacting MRCoNS carriage were assessed and estimated odds ratios (ORs) and 95% confidence intervals (CIs) by using logistic regression models. ResultsOverall, 353 drug users were eligible and included in the study. The prevalence of CoNS and MRCoNS were 42.78% and 29.18%, respectively. Having a history of being in prison (aOR = 2.16, 95% CI: 1.10−4.22) and a history of heroin snorting in the past 6 months (aOR = 1.87, 95% CI: 1.14−3.05) were risk factors for MRCoNS nasal carriage in drug users. The proportions of multidrug resistance for CoNS and MRCoNS isolates were respectively 54.38% and 66.07%. The predominant multidrug resistance pattern for CoNS and MRCoNS isolates was simultaneously non-susceptible to penicillin, cefoxitin and trimethoprim-sulfamethoxazole. MRCoNS isolates that were positive for erythromycin- (χ2 = 15.49, P < 0.001), tetracycline- (χ2 = 44.88, P < 0.001), penicillin- (χ2 = 3.86, P = 0.049), clindamycin- (χ2 = 4.18, P = 0.028), and gentamicin- (χ2 = 20.66, P < 0.001) resistance genes had significantly higher rates of resistance to corresponding antibiotics. ConclusionsThe prevalence of MRCoNS nasal carriage was high in community-based drug users. Drug users with risk factors should be paid greater attention to. The use of antibiotics in drug users needs further investigation and control.