Sensibilité aux antibiotiques des souches de Staphylocoques aureus isolées dans deux hôpitaux universitaires à Rabat, Maroc

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.

Antibiotic sensitivity profile of Staphylococcus aureus isolated from HIV/AIDS patients presenting with pyoderma, at the Yaounde Central Hospital, Cameroon

Introduction

the purpose of this study was to evaluate the in vitro activity of several antibiotics against strains of Staphylococcus aureus isolated from pyoderma in people living with Human Immunodeficiency Virus (HIV), consulting at the day clinic of the Yaoundé Central Hospital.

Methods

this was a prospective, cross-sectional study which was carried out in five months (November 2013-March 2014). Fifty-three (53) pus specimens were collected; from which the isolation of Staphylococcus aureus was made using Chapman agar. Mannitol fermentation, catalase, coagulase and DNase tests were used for species identification. Antibiotic sensitivity of each strain was determined by the agar diffusion method.

Results

forty-eight (48) strains of Staphylococcus aureus were isolated (90.56%). A high rate of sensitivity to antibiotics was observed in many strains: vancomycin (100.0%), pristinamycin (100.0%), chloramphenicol (100.0%), oxacillin (97.9%), cefoxitin (97.9%), gentamicin (87.5%), tobramycin (83.3%). However, some strains had strong resistance to penicillin G (89.6%) and cotrimoxazole (64.6%). The proportion of Methicilin Resistant strains of Staphylococcus aureus (MRSA) was low (2.0%). The kanamycin-tobramycin-gentamycin phenotype (KTG) was most common in the aminoglycosides resistant strains; the same as the induced phenotype E stains (iMLSB) in macrolides resistant strains. Conclusion: these results indicate that many of these antibiotics tested are still effective against strains of Staphylococcus aureus.

Epidemiology of common resistant bacterial pathogens in the countries of the Arab League

No uniformly organised collection of data regarding antimicrobial resistance has occurred in the countries of the Arab League. 19 countries of the Arab League have published data for antimicrobial susceptibility for the WHO priority organisms, and seven of 14 of these organisms are included in this Review (Escherichia coli, Klebsiella spp, Pseudomonas aeruginosa, Acinetobacter baumannii, Salmonella spp, Staphylococcus aureus, and Streptococcus pneumoniae). Although E coli and Klebsiella spp resistance to third-generation cephalosporins is common in all countries, with prevalence reaching more than 50% in Egypt and Syria, carbapenem resistance is emerging, albeit with a prevalence of less than 10%. Conversely, a large amount of carbapenem resistance has been reported for P aeruginosa and A baumannii across the Arab League, reaching 50% and 88% of isolates in some countries. As for Salmonella spp, the prevalence of fluoroquinolone resistance has exceeded 30% in several areas. With regards to the Gram-positive pathogens, the prevalence of meticillin resistance in S aureus is reported to be between 20% and 30% in most countries, but exceeds 60% in Egypt and Iraq. The prevalence of penicillin non-susceptibility among pneumococci has reached more than 20% in Algeria, Egypt, Morocco, Saudi Arabia, and Tunisia. These findings highlight the need for structured national plans in the region to target infection prevention and antimicrobial stewardship.

Multicentric study in five African countries of antibiotic susceptibility for three main pathogens: Streptococcus pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa

Antibiotic resistance is a growing clinical and epidemiological problem. We report on the antibiotic susceptibility of three pathogens isolated from patients in Algeria, Egypt, Morocco, Senegal, and Tunisia during 2010-2011. In total, 218 Streptococcus pneumoniae, 428 Staphylococcus aureus, and 414 Pseudomonas aeruginosa strains were collected. S. pneumoniae resistance was noted against penicillin (30.2%), erythromycin (27.4%), cefpodoxime (19.1%), amoxicillin (12.0%), cefotaxime (7.4%), and levofloxacin (3.2%). All the strains were teicoplanin susceptible. Staphylococcus aureus methicillin resistance differed between countries, from 5.0% in Senegal to 62.7% in Egypt. Levofloxacin resistance was low in all countries, and the highest rate (in Egypt) was still only 13.6% for intermediate and resistant strains combined. Most strains were susceptible to fosfomycin (99.3%) and pristinamycin (94.2%). P. aeruginosa resistance was found against levofloxacin (30.4%), ciprofloxacin (29.9%), tobramycin (19.7%), ceftazidime (19.2%), and imipenem (17.9%), but not colistin. Antibiotic susceptibility varied widely between countries, with resistance typically most prevalent in Egypt.

Antimicrobial resistance of abnormal vaginal discharges microorganisms in Ouagadougou, Burkina Faso

OBJECTIVE

To assess the prevalence of bacterial strains and fungal strains infecting the vaginal tract and test their sensitivity to antibiotics in women attending Saint Camille Medical Centre in Ouagadougou.

METHODS

From January 2008 to December 2009, a total of 2 000 vaginal swabs were cultivated for bacterial and fungal identification and isolation. Furthermore, bacterial strains were tested for their susceptibility to several antibiotics used in routine in the centre.

RESULTS

The results revealed that microbial isolation and identification was attempted for 1 536/2 000 sample, a positivity rate of 76.80%. Candida albicans (48.76%), followed by Escherichia coli (16.67%), Streptococcus agalactiae (8.14%) and Staphylococcus aureus (7.55%) were the major agents of genital tract infections in patients. Mycoplasma hominis and Ureaplasma urealyticum combined accounted for less than 7%. Trichomonas vaginalis was identified in 1.04% cases. The antimicrobial tests revealed that the microorganisms developed resistance to several antibiotics including beta lactams. However, antibiotics such as cefamenzol, ciprofloxacin and norfloxacin were still active on these bacteria.

CONCLUSIONS

The results reveal that many sexually active women are infected by one or more microbial pathogens, probably because of the lack of hygiene or the adoption of some risky behaviors, such as not using condoms or having multiple sexual partners. Efforts should be made to address these points in the country.

MRSA in Africa: filling the global map of antimicrobial resistance

We sought to assess the prevalence of methicillin-resistance among Staphylococcus aureus isolates in Africa. We included articles published in 2005 or later reporting for the prevalence of MRSA among S. aureus clinical isolates. Thirty-two studies were included. In Tunisia, the prevalence of MRSA increased from 16% to 41% between 2002–2007, while in Libya it was 31% in 2007. In South Africa, the prevalence decreased from 36% in 2006 to 24% during 2007–2011. In Botswana, the prevalence varied from 23–44% between 2000–2007. In Algeria and Egypt, the prevalence was 45% and 52% between 2003–2005, respectively. In Nigeria, the prevalence was greater in the northern than the southern part. In Ethiopia and the Ivory Coast, the prevalence was 55% and 39%, respectively. The prevalence of MRSA was lower than 50% in most of the African countries, although it appears to have risen since 2000 in many African countries, except for South Africa.

Emergence of vancomycin-resistant Staphylococcus aureus identified in the Tlemcen university hospital (North-West Algeria)

INTRODUCTION

Nosocomial infections are a matter of concern in surgical wards. Their incidence is constantly increasing, especially among immunocompromised patients who are vulnerable to colonization by opportunistic pathogens such as Staphylococcus aureus. The bacterium accumulates resistance mechanisms against antibiotics such as vancomycin. The objective of our study was to explore this resistance, to screen for Staphylococcus aureus strains resistant to vancomycin, and to try various antibiotic combinations against these strains.

PATIENTS AND METHODS

The antibiotic susceptibility of 220 S. aureus strains was determined by agar diffusion and evaluation of minimal inhibitory concentrations (MICs), by dilution technique on solid medium according to clinical and laboratory standard institute (CLSI) standards. The screening of strains resistant to vancomycin was performed on brain heart infusion agar medium, supplemented with 6μg/mL of vancomycin according to CLSI standards, and confirmed by determining MICs. The effectiveness of various antibiotic combinations was assessed by the checkerboard microplate method.

RESULTS

The results show multidrug resistance to agents known for their antistaphylococcal activity with fluctuations in the level of resistance.

CONCLUSION

Three strains proved resistant to vancomycin. The vancomycin/gentamycin combination was the most effective.