Nasal Carriage Research Articles

Impact of mass administration of azithromycin as a preventive treatment on the prevalence and resistance of nasopharyngeal carriage of Staphylococcus aureus.

Staphylococcus aureus is a major cause of serious illness and death in children, indicating the need to monitor prevalent strains, particularly in the vulnerable pediatric population. Nasal carriage of S. aureus is important as carriers have an increased risk of serious illness due to systemic invasion by this pathogen and can transmit the infection. Recent studies have demonstrated the effectiveness of azithromycin in reducing the prevalence of nasopharyngeal carrying of pneumococci, which are often implicated in respiratory infections in children. However, very few studies of the impact of azithromycin on staphylococci have been undertaken. During a clinical trial under taken in 2016, nasal swabs were collected from 778 children aged 3 to 59 months including 385 children who were swabbed before administration of azithromycin or placebo and 393 after administration of azithromycin or placebo. Azithromycin was given in a dose of 100 mg for three days, together with the antimalarials sulfadoxine-pyrimethamine and amodiaquine, on four occasions at monthly intervals during the malaria transmission season. These samples were cultured for S. aureus as well as for the pneumococcus. The S. aureus isolates were tested for their susceptibility to azithromycin (15 g), penicillin (10 IU), and cefoxitine (30 g) (Oxoid Ltd). S. aureus was isolated from 13.77% (53/385) swabs before administration of azithromycin and from 20.10% (79/393) six months after administration (PR = 1.46 [1.06; 2.01], p = 0.020). Azithromycin resistance found in isolates of S. aureus did not differ significantly before and after intervention (26.42% [14/53] vs 16.46% [13/79], (PR = 0.62 [0.32; 1.23], p = 0.172). Penicillin resistance was very pronounced, 88.68% and 96.20% in pre-intervention and in post-intervention isolates respectively, but very little Methicillin Resistance (MRSA) was detected (2 cases before and 2 cases after intervention). Monitoring antibiotic resistance in S. aureus and other bacteria is especially important in Burkina Faso due to unregulated consumption of antibiotics putting children and others at risk.

Molecular Characterization of Staphylococcus aureus Isolated from Human and Food Samples in Northern Algeria.

Staphylococcus aureus is a commensal resident of the skin and nasal cavities of humans and can cause various infections. Some toxigenic strains can contaminate food matrices and cause foodborne intoxications. The present study aimed to provide relevant information (clonal complex lineages, agr types, virulence and antimicrobial resistance-associated genes) based on DNA microarray analyses as well as the origins and dissemination of several circulating clones of 60 Staphylococcus aureus isolated from food matrices (n = 24), clinical samples (n = 20), and nasal carriers (n = 16) in northern Algeria. Staphylococcus aureus were genotyped into 14 different clonal complexes. Out of 60 S. aureus, 13 and 10 isolates belonged to CC1-MSSA and CC97-MSSA, respectively. The CC 80-MRSA-IV was the predominant S. aureus strain in clinical isolates. The accessory gene regulator allele agr group III was mainly found among clinical isolates (70.4%). Panton–Valentine leukocidin genes lukF/lukS-PV were detected in 13.3% of isolates that all belonged to CC80-MRSA. The lukF/S-hlg, hlgA, and hla genes encoding for hemolysins and leucocidin components were detected in all Staphylococcus aureus isolates. Clinical and food isolates harbored more often the antibiotic resistance genes markers. Seventeen (28.3%) methicillin-resistant Staphylococcus aureus carrying the mecA gene localized on a SCCmec type IV element were identified. The penicillinase operon (blaZ/I/R) was found in 71.7% (43/60) of isolates. Food isolates belonging to CC97-MSSA carried several antibiotic resistance genes (blaZ, ermB, aphA3, sat, tetM, and tetK). The results of this study showed that all clones were found in their typical host, but interestingly, some nasal carriers had isolates assigned to CC705 thought to be absent in humans. The detection of MRSA strains among food isolates should be considered as a potential public health risk. Therefore, controlling the antibiotics prescription for a rational use in human and animal infections is mandatory.

Mupirocin Resistance in Staphylococcus aureus Isolated from Nasal Swabs of ICU and OT Staff- A Study from A Tertiary Care Hospital

Staphylococcus aureus is one of the common causes of Healthcare-associated infection. Staphylococcus colonizes the anterior nares of the nose and tends to disseminate and secondarily colonize several other body sites including the skin and the gut. Colonized hospital personnel may be an important factor in dissemination. Staphylococcus aureus to patients and vice-versa. Mupirocin is an excellent topical anti-staphylococcal antimicrobial agent used for eradicating nasal carriage. Resistance to Mupirocin is a threat for future use of this drug in eliminating nasal carriage of Staphylococcus aureus. Thus, this study was conducted to determine the rate of Mupirocin resistance among Staphylococcus aureus isolated from nasal swabs of Health care workers (HCWs ) of Operation Theatres (OTs) and Intensive Care Units (ICUs). A single nasal swab was collected from both the anterior nares of participating health care workers of ICU and OT once at the end of their shift. Antibiotic susceptibility testing of Staphylococcus aureus to various antibiotics was done by Kirby-Bauer disk diffusion method using CLSI guidelines. High and low-level Mupirocin resistance was determined. Among 282 nasal swabs collected, Staphylococcus aureus was isolated in 62 samples. Of Staphylococcus aureus 19 came out to be Methicillin-resistant (MRSA) and the remaining 43 Methicillin sensitive (MSSA). Mupirocin resistance was seen in 3 MRSA strains and 1 MSSA strain. Thus, overall 4/62 (6.5%) strains were MupR strains. Mupirocin is the most effective antibiotic used against colonization of Staphylococcus aureus in anterior nares. Resistance to this antibiotic is thus an alarm as well as a matter of great concern. Necessary steps, policies and guidelines need to be framed to stop the spread of this resistance.

Molecular Identification and antibiotic susceptibility pattern of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA)

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is an emerging bacterium associated with a much higher incidence of clinical infection worldwide than any other strains of S. aureus. The misappropriation of non-prescribing drugs amongst university students in Pakistan has become a severe problem. The present study aims to evaluate the nasal carriage rates of Staphylococcus aureus and methicillin resistant Staphylococcus aureus (MRSA) in university students and described the history of associated risk factors. Among the 350 samples, 300 (85.71%) were S. aureus positive and 50 (14.28%) were other isolates. The positive individual includes 295 (98.33%) males and 5 (1.66%) females. A total of 16 (5.3%) S. aureus out of the total 300 were resistant to cefoxitin (MRSA) and 284 (94.66%) isolates were MSSA (Methicillin Susceptible Staphylococcus aureus). The strains were confirmed by the amplification of nuc gene analysis as S. aureus and the MRSA was confirmed with mecA gene analysis. All the samples were catalase positive, whereas 72.33% was coagulase positive and 27.66% were found as coagulase negative. Among the coagulase positive 7.37% were resistant to methicillin. The antibiotic resistance patterns showed no MRSA isolates to be resistant to Vancomycin and Linzolids. In most cases the MRSA was less susceptible to other antibiotics. It was concluded that Vancomycin and Linzolid can be used as drug of choice as no MRSA was found resistant to them. Furthermore, molecular PCR diagnosis is suggested as rapid and sensitive technique for the identification of MRSA isolates based on their mecA gene analysis.

A study of nasal carriage of methicillin-resistant staphylococcus aureus in patients undergoing hemodialysis in a tertiary care hospital of Punjab

Background: Infection is one of the major problems encountered in hemodialysis patients. The mortality rate among the patients undergoing hemodialysis remains unsatisfactorily high. Hemodialysis patients have higher nasal carriage rate of Staphylococcus aureus than the healthy population. In long-term hemodialysis patients, colonization is a significant problem and is associated with an increased risk of the bloodstream infections. The antimicrobial resistance to this pathogen is increasing rapidly, and the consequences of methicillin resistance for the outcomes of Staphylococcus aureus infections are drastic.Methods: Two swabs were collected from anterior nares of patients undergoing hemodialysis, and then these swabs were transferred to microbiology laboratory for processing. Isolated strains were subjected to antimicrobial susceptibility testing using Kirby-Bauer disc diffusion. Methicillin resistance was detected by using cefoxitin disc. Inhibition zone diameters were measured as per CLSI criteria. Vancomycin screen agar test was done. Brain heart infusion agar plates containing 6 µg/ml of vancomycin were used. S. aureus ATCC 29213 was used as reference strain.Results: It was observed that 38% (38/100) of the hemodialysis patients were carriers of S. aureus followed by CoNS, followed by aerobic spore bearers. All the S. aureus isolates (100%, 38/38) were methicillin-resistant (MRSA).Conclusions: Staphylococcal nasal carrier status in hemodialysis patients along with antibiotic susceptibility testing should be done in routine and infection control practices should be followed to prevent the transmission of MRSA among chronic hemodialysis patients.

The influence of pneumococcal conjugate vaccine-13 on nasal colonisation in a controlled human infection model of pneumococcal carriage in Malawi: a double-blinded randomised controlled trial protocol.

Streptococcus pneumoniae is the leading cause of morbidity and mortality due to community acquired pneumonia, bacterial meningitis and bacteraemia worldwide. Pneumococcal conjugate vaccines protect against invasive disease, but are expensive to manufacture, limited in serotype coverage, associated with serotype replacement, and demonstrate reduced effectiveness against mucosal colonisation. For Malawi, nasopharyngeal carriage of vaccine-type pneumococci is common in vaccinated children despite national roll-out of 13-valent pneumococcal conjugate vaccine (PCV13) since 2011. Our team has safely transferred an established experimental human pneumococcal carriage method from Liverpool School of Tropical Medicine to the Malawi-Liverpool Wellcome Trust Clinical Research Programme, Malawi. This study will determine potential immunological mechanisms for the differential effects of PCV13 on nasal carriage between healthy Malawian and UK populations. We will conduct a double-blinded randomised controlled trial to vaccinate (1:1) participants with either PCV13 or control (normal saline). After a period of one month, participants will be inoculated with S. pneumoniae serotype 6B to experimentally induce nasal carriage using the EHPC method. Subsequently, participants will be invited for a second inoculation after one year to determine longer-term vaccine-induced immunological effects. Primary endpoint: detection of inoculated pneumococci by classical culture from nasal wash recovered from the participants after pneumococcal challenge. Secondary endpoints: local and systemic innate, humoral and cellular responses to PCV-13 with and without pneumococcal nasal carriage The primary objective of this controlled human infection model study is to determine if PCV-13 vaccination is protective against pneumococcal carriage in healthy adult Malawian volunteers. This study will help us to understand the observed differences in PCV-13 efficacy between populations and inform the design of future vaccines relevant to the Malawian population. Trial Registration: Pan African Clinical Trial Registry (REF: PACTR202008503507113).

Methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage among patients with diabetes at the Korle Bu Teaching Hospital.

AimTo investigate the epidemiology of S. aureus and MRSA nasal carriage among people with diabetes at the Korle Bu Teaching Hospital in Accra, including the prevalence, predictors of carriage, and antibiotic resistance.MethodologyThis study was cross-sectional, involving 300 diabetes patients and 106 non-diabetic individuals. Swab specimens of the nares were obtained from the participants and bacteriologically-cultured. Identification and characterization of S. aureus and MRSA were based on standard bacteriological methods; antimicrobial susceptibility testing was by the Kirby-Bauer method.ResultsThe prevalence of staphylococcal carriage, the diabetes group relative to the non-diabetes group, were 31.0% and 10.4% (S. aureus), and 3.3% and 0.0% (MRSA). Presence of diabetes predisposed to S. aureus carriage, but not MRSA nor coagulase-negative staphylococci (CoNS) carriage (OR = 3.88; p < 0.0001). Colonization with CoNS was protective of S. aureus (OR = 0.039, p < 0.001) and MRSA (OR = 0.115, p = 0.043) colonization among the diabetics. The antimicrobial resistance patterns recorded among the S. aureus isolated from the diabetic individuals relative to the non-diabetics were as follows: penicillin (95% vs. 91%), tetracycline (37% vs. 27%), cotrimoxazole (30% vs. 36%), erythromycin (17% vs. 0%), norfloxacin (13% vs. 0%), clindamycin (12% vs. 0%), gentamicin (9% vs. 0%), fusidic acid (10% vs. 9%), linezolid (4% vs. 0%), and rifampicin (5% vs. 0%). The proportion of multidrug resistant S. aureus was 41% (n = 38) in the diabetes group and 0% in the non-diabetes group; this difference was statistically significant (p = 0.01).ConclusionsThe presence of diabetes predisposed the participants to S. aureus carriage by almost four folds, but not MRSA carriage. Colonization with CoNS was protective of S. aureus and MRSA carriage in the diabetes group. Finally, linezolid remains a good therapeutic agent for anti-MRSA therapy.

Surveillance for Colonization, Transmission, and Infection With Methicillin-Susceptible Staphylococcus aureus in a Neonatal Intensive Care Unit

Staphylococcus aureus is one of the leading causes of infections in neonatal intensive care units (NICUs). Most studies in this patient group focus on methicillin-resistant S aureus or the outbreak setting, whereas data for methicillin-susceptible S aureus are limited. To identify risk factors for S aureus colonization and infections in hospitalized newborns and to investigate S aureus transmission and its dynamics in a nonoutbreak setting. This monocentric cohort study in a tertiary NICU in Heidelberg, Germany, enrolled all hospitalized neonates (n = 590) with at least 1 nasal screening swab positive for S aureus. Data were collected from January 1, 2018, to December 31, 2019. Weekly screening for S aureus colonization was performed for all newborns until discharge. The primary end point was any S aureus infection until hospital discharge. Transmission of S aureus and performance of routine typing to detect transmissions were defined as the secondary outcomes of the study. In total, 590 newborns were enrolled (276 [46.8%] female and 314 [53.2%] male; 220 [37.3%] with birthweight <1500 g; 477 [80.8%] preterm; 449 [76.1%] singletons; 419 [71.5%] delivered via cesarean section). The median length of stay was 26 (range, 10-62) days. Overall, 135 infants (22.9%) were colonized by S aureus at some time during their hospital stay. The median time to first detection was 17 (interquartile range, 11-37) days. The overall incidence of S aureus infection was 1.7% (10 of 590). Low birth weight (<1500 g [odds ratio, 9.3; 95% CI, 5.9-14.6; P < .001]) and longer hospital stay (odds ratio, 2.3; 95% CI, 1.9-2.7; P < .001) were associated with colonization. Nasal carriage was significantly associated with S aureus infection (odds ratio, 8.2; 95% CI, 2.1-32.3; P = .002). A total of 123 of 135 colonization isolates were sequenced. All recoverable infection isolates (4 of 7) of newborns with colonization were genetically identical to the colonizing isolate. Whole-genome sequencing indicated 23 potential transmission clusters. The findings of this cohort study suggest that nasal colonization is a relevant risk factor for S aureus infection in a nonoutbreak NICU setting. In colonized newborns, infection and colonization isolates were genetically identical, suggesting that eradication of colonization may be a useful measure to prevent infection. Further investigations are necessary to validate and assess the generalizability of our findings.

Double-swab 5% versus single-swab 10% iodophor for reducing methicillin-resistant Staphylococcus aureus with routine chlorhexidine bathing.

In a prospective cohort study, we compared a 2-swabs-per-nostril 5% iodophor regimen with a 1-swab-per-nostril 10% iodophor regimen on methicillin-resistant Staphylococcus aureus carriage in nursing-home residents. Compared with baseline, both single-swab and double-swab regimens resulted in an identical 40% reduction in nasal carriage and 60% reduction in any carriage, skin or nasal.

The Relationship between Nasal Carriage of Staphylococcus aureus and Surgical Site Infections in a Hospital Center in Morocco.

Background Surgical site infection is a major public health problem in the world. Nasal carriage is a major risk factor for the development of nosocomial Staphylococcus aureus infection, especially methicillin-resistant Staphylococcus aureus (MRSA). Our work aims to determine the prevalence of Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and the associated risk factors and to evaluate their sensitivity to 27 antibiotics. Methods A cross-sectional study was carried out on 100 patients, hospitalized in preoperative care of surgery units at the Taza Provincial Hospital Center in the Fez-Meknes region, from January to June 2019. Samples were taken from the patient's anterior nostril using single-use sterile dry or wet cotton swabs and then analyzed in the Provincial Public Health Laboratory in Taza. The carriage of Staphylococcus aureus was studied by conventional bacteriological methods by spreading nasal swabs on Chapman culture medium, while antibiotic resistance was determined by the Mueller–Hinton agar disc diffusion method according to the recommendations described by the Antibiogram Committee of the French Society of Microbiology 2019 (CA SFM 2019). Results Of the 84 patients found to be positive, 45.24% had coagulase-positive Staphylococcus aureus and 54.76% had coagulase-negative Staphylococcus. After surgery in the postoperative phase, 16 patients developed surgical site infections, of which two had a negative nasal culture and 14 had positive nasal culture. Among the Staphylococcus aureus-positive patients, 36.84% were colonized by a methicillin-resistant Staphylococcus aureus (MRSA) and 63.16% by a methicillin-sensitive Staphylococcus aureus (MSSA). Of these, 57.14% of MRSA colonized patients developed an infection of the surgical site and 42.85% showed no sign of SSI, while for patients colonized by MSSA, 16.67% developed SSI and 83.33% showed no sign of SSI. Moreover, children were the most affected by MRSA. Concerning antibiotic sensitivity, multiresistance of MRSA to more than 3 antibiotics has been found. Conclusion To the best of our knowledge, this is the first study carried out in this hospital center with the aim of knowing the prevalence of nasal carriage of Staphylococcus aureus and MRSA and to identify the risk factors in order to prevent infections related to nasal carriage of Staphylococcus aureus and MRSA.

Neutrophil function and bactericidal activity against Staphylococcus aureus after cardiac surgery with cardiopulmonary bypass.

Staphylococcus aureus is the main bacterial pathogen encountered in mediastinitis after cardiac surgical procedures; it remains a devastating complication with a high mortality rate. As neutrophils have a primordial role in the defense against staphylococcus infection and cardiopulmonary bypass (CPB) is known to induce immunosuppression, the aim of this study was to investigate CPB impact on neutrophil functions. Patients without known immunosuppression scheduled for cardiac surgery with CPB were included. Bone marrow and blood samples were harvested before, during, and after surgery. Neutrophil phenotypic maturation and functions (migration, adhesion, neutrophil extracellular trap [NET] release, reactive oxygen species (ROS) production, phagocytosis, and bacteria killing) were investigated. Two types of Staphylococcus aureus strains (one from asymptomatic nasal carriage and another from mediastinitis infected tissues) were used to assess in vitro bacterial direct impact on neutrophils. We found that CPB induced a systemic inflammation with an increase in circulating mature neutrophils after surgery. Bone marrow sample analysis did not reveal any modification of neutrophil maturation during CPB. Neutrophil lifespan was significantly increased and functions such as NET release and ROS production were enhanced after CPB whereas bacteria killing and phagocytosis were not impacted. Results were similar with the two different isolates of Staphylococcus aureus. These data suggest that CPB induces a recruitment of mature neutrophils via a demargination process rather than impacting their maturation in the bone marrow. In addition, neutrophils are fully efficient after CPB and do not contribute to postoperative immunosuppression.

Nasal Carriage of Methicillin-Resistant Staphylococcus aureus among Healthcare Workers in a Tertiary Care Hospital, Kathmandu, Nepal.

Introduction Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common causes of nosocomial infections. One of the potential risk factors for nosocomial staphylococcal infections is colonization of the anterior nares of healthcare workers (HCWs). Our study aimed to determine the rate of nasal carriage MRSA among HCWs at Manmohan Memorial Medical College and Teaching Hospital, Kathmandu. Methods Two hundred and thirty-two nasal swabs were collected from HCWs of Manmohan Memorial Medical College and Teaching Hospital, Kathmandu, Nepal, within six months (February 2018–July 2018). Nasal swabs were cultured, and S. aureus isolates were subjected to the antimicrobial susceptibility test by the modified Kirby–Bauer disc diffusion method. MRSA and iMLSB (inducible macrolide lincosamide streptogramin B) resistance was screened using the cefoxitin disc (30 μg) and D-test (clindamycin and erythromycin sensitivity pattern), respectively, following CLSI (Clinical and Laboratory Standard Institute) guidelines. Risk factors for MRSA colonization were determined using the chi-square test considering the p value ˂0.05 as significant. Results A total of 34/232 (14.7%) S. aureus were isolated, out of which 12 (35.3%) were MRSA. The overall rate of nasal carriage MRSA among HCWs was 5.2% (12/232). Colonization of MRSA was higher in males (8.7%) than in females (4.3%). MRSA colonization was found to be at peak among the doctors (11.4%). HCWs of the postoperative ward were colonized highest (18.2%). All MRSA isolates were sensitive to linezolid and tetracycline. iMLSB resistance was shown by 7(20.6%) of the isolates. MRSA strains showed higher iMLSB resistance accounting for 33.3% (4/12) in comparison to methicillin-susceptible strains with 13.6% (3/22). Smoking was found to be significantly associated with MRSA colonization (p=0.004). Conclusion Rate of nasal carriage MRSA is high among HCWs and hence needs special attention to prevent HCW-associated infections that may result due to nasal colonization.

Ecology and Genetic Lineages of Nasal Staphylococcus aureus and MRSA Carriage in Healthy Persons with or without Animal-Related Occupational Risks of Colonization: A Review of Global Reports.

In this conceptual review, we thoroughly searched for appropriate English articles on nasal staphylococci carriage among healthy people with no reported risk of colonization (Group A), food handlers (Group B), veterinarians (Group C), and livestock farmers (Group D) published between 2000 and 2021. Random-effects analyses of proportions were performed to determine the pooled prevalence of S. aureus, MRSA, MRSA-CC398, and MSSA-CC398, as well as the prevalence of PVL-positive S. aureus from all eligible studies. A total of 166 eligible papers were evaluated for Groups A/B/C/D (n = 58/31/26/51). The pooled prevalence of S. aureus and MRSA in healthy humans of Groups A to D were 15.9, 7.8, 34.9, and 27.1%, and 0.8, 0.9, 8.6, and 13.5%, respectively. The pooled prevalence of MRSA-CC398 nasal carriage among healthy humans was as follows: Group A/B (<0.05%), Group C (1.4%), Group D (5.4%); and the following among Group D: pig farmers (8.4%) and dairy farmers (4.7%). The pooled prevalence of CC398 lineage among the MSSA and MRSA isolates from studies of the four groups were Group A (2.9 and 6.9%), B (1.5 and 0.0%), C (47.6% in MRSA), and D (11.5 and 58.8%). Moreover, MSSA-CC398 isolates of Groups A and B were mostly of spa-t571 (animal-independent clade), while those of Groups C and D were spa-t011 and t034. The MRSA-CC398 was predominately of t011 and t034 in all the groups (with few other spa-types, livestock-associated clades). The pooled prevalence of MSSA and MRSA isolates carrying the PVL encoding genes were 11.5 and 9.6% (ranges: 0.0–76.9 and 0.0–28.6%), respectively. Moreover, one PVL-positive MSSA-t011-CC398 isolate was detected in Group A. Contact with livestock and veterinary practice seems to increase the risk of carrying MRSA-CC398, but not in food handlers. Thus, this emphasizes the need for integrated molecular epidemiology of zoonotic staphylococci.

Determination of nasal carriage and skin colonization, antimicrobial susceptibility and genetic relatedness of Staphylococcus aureus isolated from patients with atopic dermatitis in Szczecin, Poland

BackgroundAtopic dermatitis (AD) is one of the most frequent chronic and inflammatory skin condition. AD is characterized by damaged epidermal barrier, xerosis and pruritus of eczematous skin lesions which tend to flare. The duration and frequency of exacerbation of AD symptoms markedly affects the quality of patient life. AD results from the interplay between host genetics, immunity, and environmental factors, however the detailed pathogenesis of this disease is still not entirely cleared. Furthermore, disturbances of the skin microbiota and skin functional impairment predispose to secondary skin infections. Staphylococcus aureus colonizes skin and mucous membranes of 20 to 80% of healthy individuals and of 90% of patients with AD in whom this bacterium is accounted as an important AD exacerbating factor. It is also proven, that S. aureus nasal carriage significantly increases the risk for self-transmission and endogenous infection. In the current study the presence of S. aureus either in nasal vestibule and on lesioned skin of 64 patients with AD enrolled in 10-year autovaccination program was determined. The genetic relatedness of 86 S. aureus isolated from patients nose and skin using Pulsed Field Gel Electrophoresis (PFGE) and antimicrobial susceptibility of all strains to methicillin, erythromycin, clindamycin, mupirocin, gentamicin, amikacin, tetracycline, chloramphenicol and cotrimoxazole was also evaluated.ResultsIn total 23 PFGE genotypes and 24 unique patterns were distinguished. 34 patients were S. aureus nasal carriers. Simultaneous presence of S. aureus in nose and on affected skin was found in 16 carriers colonized by indistinguishable or potentially related S. aureus vs 2 carriers colonized with non-related S. aureus in nasal vestibule and on skin.4 isolates were methicillin resistant (MRSA) among which 3 showed constitutive MLSB resistance phenotype and remaining one was resistant to tetracycline and chloramphenicol.In 4 isolates inducible MLSB resistance phenotype was found, one of them was additionally resistant to tetracycline. 7 S. aureus were mupirocin resistant among them 3 - isolated from one patient, were resistant simultaneously to tetracyclines and chloramphenicol. 7 strains demonstrated resistance to chloramphenicol and susceptibility to all tested antimicrobial agents. The susceptibility to gentamicin, amikacin and cotrimoxazole among all examined S. aureus was confirmed.ConclusionThe obtained results indicated non-clonal structure of S. aureus circulating in AD patients. PFGE results showed the clonal-structure of vast majority of S. aureus isolated from nose and skin from nasal carriers what may prove the autoinfection in these patients. All examined patients the moderate or strong severity of AD was reported. Susceptibility to most antibiotics among isolated strains was also observed.

Incidence of Methicillin Resistant Staphylococcus aureus Isolated from Nostrils of Mouau Students

Aim: This study is carried out to determine the prevalence of nasal carriage of staphylococcus aureus among Michael Okpara University of Agriculture Umudike (MOUAU) students and determine the antibiotics susceptibility pattern.&#x0D; Methods: Nasal swab specimens collected from the anterior nares were cultured on mannitol salt agar. S.aureus isolates were identified by mannitol fermentation, coagulase positivity and catalase positivity. Antimicrobial susceptibility test was performed on Meuller-Hinton Agar (MHA) by modified Kirby-Bauer disc diffusion method.&#x0D; Result: Out of the 100 swabs collected, S.aureus was isolated from 60% of the samples. Among colonized students, 63.3% (n=38) were from male students whereas 36.7% (n=22) were from female. The antibiotic susceptibility pattern of the Staphylococcus aureus isolates indicates that Staphylococcus aureus isolates showed high rate of sensitivity towards antibiotics as follows; Gentamycin (81.67%), followed by Ciprofloxacin (80%), Levofloxacin (76.67%), Ceftriaxone (58.33%), and resistance towards antibiotics Imipenem (100%) followed by Cefotaxime (90%), Cefexime (83.33%), Cefoxitin (65%), azithromycin (55%) and cefuroxime (50%).&#x0D; Conclusion: This study showed a high rate of nasal carriage of Staphylococcus aureus among MOUAU students and a high incidence of antibiotics resistant Staphylococcus aureus carriage.

Hospitalization and colonization by methicillin-resistant Staphylococcus aureus in the surgical department of 03 health facilities in the Nd\xe9 division, West-Cameroon

BackgroundCommensal flora colonization during hospitalization by bacteria is the first step for nosocomial infections while antibiotic resistance reduces therapeutic options. In aim to control this phenomenon, we initiated this study to describe the impact of hospitalization on colonization by methicillin-resistant Staphylococcus aureus in the surgical department of 03 health facilities in the Ndé division, West-Cameroon.MethodsThis study was carried out on patients admitted for surgery in 03 health facilities of the Ndé division, West-Cameroon (District Hospital of Bangangté, Protestant Hospital of Bangwa and Cliniques Universitaires des Montagnes). After obtaining ethical clearance and authorizations, nasal swabs were performed at admission and discharge, with the aim of isolating bacteria and performing their antibiotic susceptibility tests. Informations on each participant's antibiotic therapy were recorded. Laboratory investigations were carried out according to standard protocols (CASFM, 2019).ResultsThe most commonly used antibiotics were β-lactams. A total of 104 nasal swabs were performed on 52 patients who agreed to participate to the study. From the analysis, 110 (57 at admission versus 53 at discharge) Staphylococcus isolates were obtained. Overall, susceptibility testing showed that antibiotic resistance rates were higher at discharge than at admission; with significant differences between the susceptibility profiles obtained at admission and discharge for β-lactams and not significant for fluoroquinolones and aminoglycosides. Globally, frequency of nasal carriage of methicillin-resistant Staphylococcus aureus at discharge 16 (30.77%) was significantly higher than at admission 07 (13.46%) with Chi-2 = 4.52 and p = 0.0335.ConclusionThe high rates of antibiotic resistance of bacteria isolated at discharge compared to those isolated at admission obtained in the present investigation, highlights the important role that hospitalization plays in the selection and dissemination of methicillin-resistant Staphylococcus aureus and colonization by these bacteria in health structures of Ndé division. As a result, further investigations to find the factors that promote this phenomenon should be carried out.

Vitamin D and Cathelicidin (LL-37) Status in Patients with Type 2 Diabetes and Staphylococcus aureus Nasal Carriage.

OBJECTIVEType 2 diabetes mellitus (T2D) is characterized by the dysregulation of innate immunity leading to higher rates of Staphylococcus aureus nasal carriage, an important risk factor for severe infections. 25-hydroxy vitamin D (25(OH) D) may contribute, via the production of the antimicrobial peptide cathelicidin (LL-37), to epithelial host defense against S. aureus. This study evaluated whether 25(OH)D and LL-37 levels determine S. aureus nasal carriage.METHODSTwo consecutive nasal swabs were obtained from 118 T2D patients to determine S. aureus nasal carriage status. Serum levels of 25(OH)D and LL-37 were measured using chemiluminescence immunoassay and enzyme-linked immunosorbent assay, respectively. Supplementation of vitamin D by a number of participants was taken into account and evaluated.RESULTSForty-two T2D patients (35.6%) were found to be colonized by S. aureus. Vitamin D deficiency was detected in sixty-nine patients (65.7%). Median value for LL-37 in T2D patients was 0.89 ng/ml (range 0.05-8.62 ng/ml). Circulating levels of LL-37 were higher in nasal carriers compared to non-carriers (1.25 ng/ml vs 0.72 ng/ml; p < 0.001). No difference was found in serum 25(OH) D levels between carriers and non-carriers. 25(OH)D and LL-37 serum levels correlated positively in non-carriers, while the relationship was inversed in the carrier group. Vitamin D supplementation was not associated with lower incidence of S. aureus nasal carriage (p = 0.706).CONCLUSIONST2D patients presented decreased serum levels of 25(OH)D and LL-37, indicating a potential impairment of innate immunity. Expression of LL-37 may be induced by S. aureus nasal carriage among people with diabetes. Vitamin D supplementation did not influence S. aureus nasal colonization in T2D patients.

Molecular Characterization and Antimicrobial Susceptibility of Methicillin-Resistant Staphylococcus Aureus Isolates from Clinical Samples and Asymptomatic Nasal Carriers in Istanbul (Turkey)

Methicillin-resistant Staphylococcus aureus (MRSA) has been a widespread problem in Turkish hospitals. The aim of this study was to investigate the staphylococcal toxin genes of the clinical and nasal MRSA isolates, and their antibiotic resistance profiles. Isolation of nasal and clinical bacteria was done following standard microbiological methods. The presence of antimicrobial resistance genes (mec A, pvl, tsst-1, and SEs genes) was determined using the real-time polymerase chain reaction (PCR) assay. Among nasal MRSA isolates, 66.7% were toxigenic. The distribution of genes was as follows: pvl 26.7%, tsst-1 3.3%, and SEs 36.7%. Therefore, the nasal MRSA isolates had a rate of 23.3% multidrug resistance (MDR) pattern to the non-beta-lactams antibiotics. All (100%) clinical MRSA isolates were found to be toxigenic. The distribution of genes was as follows; pvl 10%, tsst-1 6.7%, and SEs 100%. The clinical MRSA isolates had a rate of 60% MDR. Following detection of pvl, tsst-1, and SEs among nasal and clinical MRSA isolates, and the presence of high antimicrobial resistance, the spread of these strains may be an additional factor contributing to the emergence of community-acquired (CA)-MRSA and hospital-acquired (HA)-MRSA. This study is the first to determine the resistance to linezolid and tigecycline in both nasal and clinical MRSA isolates, for the first time in Turkey. All nasal and clinical MRSA isolates were uniformly susceptible to vancomycin and quinupristin-dalfopristin. Our findings show that MRSA infections in Turkey can be empirically treated with vancomycin and quinupristin-dalfopristin based on the lack of demonstrable resistance to these drugs.

Intense intestinal carriage and subsequent acquisition of multidrug-resistant enterobacteria in neonatal intensive care unit in Morocco.

This study was conducted in order to know the colonization rate of MDR enterobacteria in neonates during their hospitalization in neonatal intensive care unit (NICU). Furthermore, we investigated risk factors for potential colonization and molecular epidemiology of isolated resistant bacteria. This prospective study was carried out in the neonatology and intensive care unit department of the University Hospital of Fez (Morocco) from February 2013 to July 2015. All consecutive admitted newborns were screened for intestinal and nasal carriage of MDR enterobacteria at admission of the babies and during the hospitalization. During the study period, a total of 641 Enterobacteriaceae were isolated and Klebsiella pneumoniae was the predominated bacteria. Bacterial identification and antibiograms were performed according to the international standards. On admission, 455 newborns were screened. A median age of these newborns was 1 day with an extended 147 days and their average weight was 2612 ± 1023 grams. 22.4% of neonates were found colonized by an ESBL producing Enterobacteriaceae (ESBL-E), 8.7% by a carbapenemases producing Enterobacteriaceae (CPE). During hospitalization, 207 of newborns were included in the acquisition study. 59.4% of newborns acquired an ESBL-E during their stay, 12.5% has acquired CPE. The blaCTXM-15 gene was the most frequently detected (81.2%) among ESBL-E. While, all CPE has expressed the blaOXA-48 gene exclusively. Two risk factors have been significantly associated with MDR enterobacteria colonization at admission which are newborns admission from maternity of the university hospital (95% CI, 1.859–5.129, P = 0.000) and neurological distress (95% CI, 1.038 to 4.694, P = 0.040). During hospitalization, the none risk factor was significantly associated with the carriage of MDR-E. The high rate of colonization, the MDR enterobacteria and the resistance genes found represent good indicator of cross-transmission in the NICU. An active strategy to control the spread of MDR enterobacteria should be applied.

Epidemiological assessment of nasal carriage of Staphylococcus aureus among patients for whom dental implantation is planned

Epidemiological assessment of nasal carriage of Staphylococcus aureus among patients for whom dental implantation is planned