The EPISA study: antimicrobial susceptibility of Staphylococcus aureus causing primary or secondary skin and soft tissue infections in the community in France, the UK and Ireland

An Overview of Antimicrobial Resistance in Saudi Arabia (2013-2023) and the Need for National Surveillance

Antimicrobial resistance (AMR) is a well-recognized global threat. The World Health Organization (WHO) issued a report ranking the critical types of bacterial resistance that need to be monitored. Several studies from individual institutions in Saudi Arabia have reported rates of antimicrobial resistance using automated methods. However, no national surveillance study has been conducted to date using gold standard methods for antimicrobial susceptibility testing. This review summarizes AMR rates for major bacterial pathogens in Saudi Arabia and provides a justification for the need for a national surveillance project. In Saudi Arabia, AMR rates for both Gram-positive and Gram-negative bacteria are on the rise. Surveillance studies help identify AMR trends and emergence of outbreaks. The WHO has started a program, the Global Antimicrobial Resistance Surveillance System (GLASS), encouraging its member states, including Saudi Arabia, to conduct antimicrobial surveillance studies to estimate AMR rates worldwide. Of the microbiological methods used to test antimicrobial susceptibility, only broth microdilution (BMD) is considered the "gold standard." As AMR studies in Saudi Arabia are sparse, mostly limited to single centers and were conducted using automated methods, a national AMR surveillance project is needed to evaluate the current status and to inform stewardship decisions.

Prevalence of enterotoxin genes (SEA to SEE) and antibacterial resistant pattern of Staphylococcus aureus isolated from clinical specimens in Assiut city of Egypt

Background

Infections in communities and hospitals are mostly caused by Staphylococcus aureus strains. This study aimed to determine the prevalence of five genes (SEA, SEB, SEC, SED and SEE) encoding staphylococcal enterotoxins in S. aureus isolates from various clinical specimens, as well as to assess the relationship of these isolates with antibiotic susceptibility. Traditional PCR was used to detect enterotoxin genes, and the ability of isolates expressing these genes was determined using Q.RT-PCR.

Results

Overall; 61.3% (n = 46) of the samples were positive for S. aureus out of 75 clinical specimens, including urine, abscess, wounds, and nasal swabs. The prevalence of antibiotic resistance showed S. aureus isolates were resistant to Nalidixic acid, Ampicillin and Amoxicillin (100%), Cefuroxime (94%), Ceftriaxone (89%), Ciprofloxacin (87%), Erythromycin and Ceftaxime (85%), Cephalexin and Clarithromycin (83%), Cefaclor (81%), Gentamicin (74%), Ofloxacin (72%), Chloramphenicol(59%), Amoxicillin/Clavulanic acid (54%), while all isolates sensitive to Imipinem (100%). By employing specific PCR, about 39.1% of isolates were harbored enterotoxin genes, enterotoxin A was the most predominant toxin in 32.6% of isolates, enterotoxin B with 4.3% of isolates and enterotoxin A and B were detected jointly in 2.1% of isolates, while enterotoxin C, D and E weren’t detected in any isolate.

Conclusion

This study revealed a high prevalence of S. aureus among clinical specimens. The isolates were also multidrug resistant to several tested antibiotics. Enterotoxin A was the most prevalent gene among isolates. The presence of antibiotic resistance and enterotoxin genes may facilitate the spread of S. aureus strains and pose a potential threat to public health.

The global prevalence of fusidic acid resistance in clinical isolates of Staphylococcus aureus: a systematic review and meta-analysis

BACKGROUND AND AIM

Staphylococcus aureus (S. aureus) is one of the most common pathogens causing nosocomial and community-acquired infections with high morbidity and mortality rates. Fusidic acid has been increasingly used for the treatment of infections due to methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). The present study aimed to determine the precise prevalence of fusidic acid resistant MRSA (FRMRSA), fusidic acid resistant MSSA (FRMSSA), and total fusidic acid resistant S. aureus (FRSA) on a global scale.

METHODS

Several international databases including Medline, Embase, and the Web of Sciences were searched (2000-2020) to discern studies addressing the prevalence of FRSA, FRMRSA, and FRMSSA. STATA (version14) software was used to interpret the data.

RESULTS

Of the 1446 records identified from the databases, 215 studies fulfilled the eligibility criteria for the detection of FRSA (208 studies), FRMRSA (143 studies), and FRMSSA (71 studies). The analyses manifested that the global prevalence of FRSA, FRMRSA, and FRMSSA was 0.5%, 2.6% and 6.7%, respectively.

CONCLUSION

This meta-analysis describes an increasing incidence of FRSA, FRMSSA, and FRMRSA. These results indicate the need for prudent prescription of fusidic acid to stop or diminish the incidence of fusidic acid resistance as well as the development of strategies for monitoring the efficacy of fusidic acid use.

The Prevalence and Risk Factors Associated with Nasal Methicillin-Resistant Staphylococcus Aureus Colonization among Children in a Tertiary Hospital in Nigeria

Background

Nasal methicillin-resistant Staphylococcus aureus (MRSA) colonization is of public health concern due to increased risk of developing invasive infections and the therapeutic challenges. This concern is more among the vulnerable group. We determined the prevalence and associated risk factors of MRSA nasal carriage among children in a tertiary hospital in Nigeria.

Method

We conducted a hospital-based, cross-sectional study among 300 children attending the outpatient clinic of a tertiary hospital recruited through systematic sampling technique. An interviewer-administered, structured questionnaire was used to obtain sociodemographic characteristics and exposure factors. Nasal swabs samples were collected and inoculated on mannitol salt agar and subcultured on nutrient agar to isolate Staphylococcus aureus. We used the conventional Polymerase Chain Reaction (PCR) technique to detect the presence of mecA gene for MRSA. We calculated the prevalence, prevalence odds ratio to determine risk factors for MRSA acquisition at 5% level of significance.

Results

The median age was 1.7 years (6 months-16 years). Males accounted for 60.7%, and 75% of the participants were under 5 years. Staphylococcus aureus colonization was found in 36.3% of the participants while 5.3% of the participants had MRSA identified by detecting the mecA gene. History of recent surgery in the last six months was the only independent predictor of nasal MRSA colonization among the participants (aOR=12.5; 95%CI: 2.7–50.0.)

Conclusion

The high prevalence of MRSA colonization observed among the children in this study suggests the need to consider screening children with history of previous surgery as infection control and prevention intervention for MRSA.

Ozenoxacin, a New Effective and Safe Topical Treatment for Impetigo in Children and Adolescents

BACKGROUND

Ozenoxacin is a topical antibiotic approved in Europe to treat non-bullous impetigo in adults and children aged ≥6 months. This analysis evaluated the efficacy and safety of ozenoxacin in paediatric patients by age group.

METHODS

Pooled data for patients aged 6 months to <18 years who had participated in a phase I or in two phase III clinical trials of ozenoxacin 1% cream were analysed by age group: 0.5-<2, 2-<6, 6-<12, and 12-<18 years.

RESULTS

The combined population comprised 529 patients with non-bullous impetigo treated with ozenoxacin (n = 239), vehicle (n = 201), or retapamulin as internal validation control (n = 89). Studies were well matched for extent and severity of impetigo and therapeutic schedule (twice daily application for 5 days). The clinical success rate after 5 days' treatment (day 6-7, end of therapy), and microbiological success rates after 3-4 days' treatment and at the end of therapy, were significantly higher with ozenoxacin than vehicle (p < 0.0001 for all comparisons). Clinical and bacterial eradication rates were higher with ozenoxacin than vehicle in each age group. No safety concerns were identified with ozenoxacin. One (0.3%) of 327 plasma samples exceeded the lower limit of quantification for ozenoxacin, but the low concentration indicated negligible systemic absorption.

CONCLUSION

This combined analysis supports the efficacy and safety of ozenoxacin administered twice daily for 5 days. Ozenoxacin 1% cream is a new option to consider for treatment of non-bullous impetigo in children aged 6 months to <18 years.

Microbiological profile of ozenoxacin

Aim: To explore the antibacterial spectrum of ozenoxacin and compare its in vitro activity with that of other antibacterial agents. Materials & methods: In 2010, 10,054 isolates were collected from 128 centers worldwide. Minimum inhibitory concentrations against Gram-positive and Gram-negative isolates were determined for 23 and 13 antibacterial agents, respectively. Results: Ozenoxacin exhibited high in vitro activity against susceptible, and methicillin- or levofloxacin-resistant, Gram-positive bacteria. Ozenoxacin was one or two dilutions less active against Enterobacteriaceae isolates, except for Escherichia coli, than other quinolones. Conclusion: Ozenoxacin is a potent antimicrobial agent mainly against susceptible and resistant strains of Gram-positive isolates (staphylococci and streptococci), and shows activity against some Gram-negative isolates.

Emerging of antimicrobial resistance in staphylococci isolated from clinical and food samples in Algeria

Objective

The antimicrobial resistance of staphylococci rose worldwide. In total, 96 Staphylococcus isolates from food and clinical samples were collected from two provinces in Algeria. The antimicrobial susceptibility testing was performed and resistance-associated genes were detected.

Results

Fifty-one strains were isolated from food samples and differentiated into 33 Staphylococcus aureus and 18 coagulase-negative staphylococci. Forty-five staphylococci were collected from hospital and community-acquired infection cases. All S. aureus isolated from food were resistant to penicillin and 45.5% were resistant to tetracycline. The resistance rates of 45 clinical Staphylococcus isolates were 86.7%, 48.9%, 37.8% and 20.0% to penicillin, tetracycline, erythromycin and kanamycin, respectively. Nine isolates were confirmed as MRSA from food and clinical isolates. One S. aureus originated from food was confirmed as vancomycin-resistant. Multidrug-resistance was observed among 25.5% and 53.3% of food and clinical staphylococci, respectively. The tetM/K, blaZ, aacA-aphD, ermC and mecA genes were detected in food and clinical isolates. ermA gene was not found. This study provided insight into the status of antimicrobial resistance of staphylococci isolated from food and clinical samples in Algeria. Further investigations and surveillance programmes are mandatory.

Variability of antibiotic susceptibility and toxin production of Staphylococcus aureus strains isolated from skin, soft tissue, and bone related infections

Background

Staphylococcus aureus is an opportunistic commensal bacterium that mostly colonizes the skin and soft tissues. The pathogenicity of S. aureus is due to both its ability to resist antibiotics, and the production of toxins. Here, we characterize a group of genes responsible for toxin production and antibiotic resistance of S. aureus strains isolated from skin, soft tissue, and bone related infections.

Results

A total of 136 S. aureus strains were collected from five different types of infection: furuncles, pyomyositis, abscesses, Buruli ulcers, and osteomyelitis, from hospital admissions and out-patients in Benin. All strains were resistant to benzyl penicillin, while 25% were resistant to methicillin, and all showed sensitivity to vancomycin. Panton-Valentine leukocidin (PVL) was the most commonly produced virulence factor (70%), followed by staphylococcal enterotoxin B (44%). Exfoliative toxin B was produced by 1.3% of the strains, and was only found in isolates from Buruli ulcers. The tsst-1, sec, and seh genes were rarely detected (≤1%).

Conclusions

This study provides new insight into the prevalence of toxin and antibiotic resistance genes in S. aureus strains responsible for skin, soft tissue, and bone infections. Our results showed that PVL was strongly associated with pyomyositis and osteomyelitis, and that there is a high prevalence of PVL-MRSA skin infections in Benin.

Staphylococcus aureus and topical fusidic acid use: results of a clinical audit on antimicrobial resistance

BACKGROUND

Fusidic acid (FA) resistance in Staphylococcus aureus poses a problem for treating systemic methicillin-resistant S. aureus infection, in which FA may otherwise remain a viable option. It can also result in treatment failure of common dermatological conditions such as impetigo and infected atopic eczema. Several studies have linked trends in prescribing medication and topical use of FA to development of resistance. However, few case-control studies have evaluated risk factors for developing FA resistance in S. aureus.

METHODS

A clinical audit for antimicrobial resistance was performed in dermatology patients from the National Skin Centre who were admitted for inpatient care from 2006 to 2008 and had positive bacterial cultures for S. aureus. Each FA-resistant S. aureus (FRSA) case was compared with four randomly selected FA-susceptible (FSSA) cases. Medical records were reviewed retrospectively, and potential risk factors for development of resistance were analyzed.

RESULTS

Thirteen of 37 patients with FRSA (35.1%) had used FA topically compared with 11 of 148 patients with FSSA (7.4%). Findings from multivariate analysis indicate that previous use of topical FA was the only independent risk factor of FA resistance (adjusted OR 7.46, 95% CI [2.60-21.41], P < 0.001). Patients' coexisting illnesses, recent hospitalization, or systemic antibiotic use were not significant risks.

CONCLUSIONS

Previous recent topical FA use correlated positively with FA resistance in S. aureus. Prescribing physicians must be vigilant of the rise of FA resistance and its resultant problems and prescribe topical FA discerningly.

Antibacterial resistance, genes encoding toxins and genetic background among Staphylococcus aureus isolated from community-acquired skin and soft tissue infections in France: a national prospective survey

The epidemiology of staphylococcal community-acquired skin and soft tissues infections (CA-SSTIs) has changed dramatically. We described prospectively the characteristics of the Staphylococcus aureus isolated from 71 non-teaching French hospitals and implicated in CA-SSTIs: antimicrobial susceptibility (mecA polymerase chain reaction [PCR], disk diffusion method), virulence factor gene (sea, tst, pvl) prevalence and genetic background (agr allele). During November 2006, 235 strains were collected (wound infection: 51%, abscess: 21%, whitlow: 8%, diabetic foot: 7%, furunculosis: 3%). sea, tst and pvl were identified in 22.1, 13.2 and 8.9% strains, respectively. agr allele 1 was the most frequently encountered genetic background, whatever the methicillin susceptibility. Among the 34 methicillin-resistant S. aureus (MRSA, 14.5% of all S. aureus), only one strain (2.9%) harboured pvl (belonging to the European ST80 clone), four (11.8%) tst (belonging to two endemic French clones) and 18 (52.9%) sea gene (mainly the Lyon clone). According to their in vitro activity, pristinamycin or trimethoprim/sulfamethoxazole could be considered as first-choice antibiotics. To date, the international pvl-positive MRSA clones have not spread in France. MRSA strains isolated from putative CA-SSTIs exhibited a genetic and phenotypic background of hospital-acquired (HA) clones. National survey should be continued, in order to monitor the emergence of virulent clones.

Staphylococcus aureus skin and soft tissue infections in primary healthcare in Denmark: a 12-year population-based study

A rise in community-onset Staphylococcus aureus infections has been observed in European countries. To ascertain secular trends of S. aureus infections in primary healthcare in Denmark, we conducted this register-based study in the North Denmark region, during the period 1997-2008. We identified all skin and mucosa specimens obtained by general practitioners and all prescriptions for the preferred oral anti-staphylococcal antibiotic, dicloxacillin. Repeat observations within a 12-month period were excluded prior to the calculation of age and gender standardised incidence rates per 100,000 person-years. We included 108,758 specimens, of which 42,778 (39%) yielded S. aureus. The annual incidence rate of specimens doubled during the study period, reaching 2,399 in 2008. The overall rate of S. aureus isolates increased 2-fold to a stable rate at about 850, but for isolates from children and for impetigo specimens, the increase was steeper, with a peak in 2002. A total of 156,462 dicloxacillin prescriptions had been redeemed and the annual prescription rate increased 2.5-fold, peaking at 3,714 in 2007. In conclusion, the annual rates of specimens, S. aureus infections and dicloxacillin prescriptions more than doubled in primary healthcare during the 12-year study period. A major impetigo epidemic and calls for antibiotic stewardship with increased utilisation of specimens were contributing factors.

Antibiotic sensitivity pattern of Staphylococcus aureus from clinical isolates in a tertiary health institution in Kano, Northwestern Nigeria

Background

The importance of Staphylococcus aureus as a persistent nosocomial and community acquired pathogen has become a global health concern. It has a remarkable capability of evolving different mechanisms of resistance to most antimicrobial agents. The aim of the present study is to establish the incidence of S. aureus in clinical specimens and its antibiotic sensitivity pattern to various antibiotics in this locality.

Methods

One hundred and fifty consecutive isolates of S. aureus obtained from various clinical specimens between January and December 2009 sent to the Medical Microbiology Laboratory Department of Aminu Kano Teaching Hospital (AKTH) were confirmed by standard bacteriological procedures. Antibiotic sensitivity pattern was carried out by disc diffusion method.

Results

The age group with the highest number of isolates was (0-10)yrs while wound infection had the highest frequency of S. aureus isolates (30.7%) in the study. Males (62.0%) were more infected than females (38.0%). The sensitivity pattern of S. aureus to the following antibiotics; Gentamicin, Amoxycillin/clavulanate, Streptomycin, Cloxacillin, Erythromycin, Chloramphenicol, Cotrimoxazole, Tetracycline, Penicillin, Ciprofloxacin, Ofloxacin, Levofloxacin, Ceftriaxone, Amoxycillin and vancomycin were 92.4%, 63.0%, 44.2%, 35.8%, 52.4%, 61.9%, 15.5%, 31.2%, 7.1%, 78.9%, 76.6%, 100%, 71.4%, 30.7% and 100% respectively. Methicillin resistant isolates were sensitive to Levofloxacin 93.7% and Ofloxacin 68.7%.

Conclusion

The results of the present study show that the fluoroquinolones are effective in the management of Staphylococcus aureus infections including methicillin resistant strains in this environment.

A study on antimicrobial susceptibility pattern in clinical isolates of Staphylococcus aureus in Eritrea

Background:

Staphylococcus aureus is a major pathogen in skin and soft tissue infections. Methicillin resistant S.aureus (MRSA) is prevalent in most of the countries wherever it is sought for. MRSA is one of the important pathogens implicated in hospital acquired infection. The main objectives of this study was to find out the antimicrobial susceptibility pattern of S.aureus isolates, the prevalence of methicillin resistant S.aureus (MRSA) and nasal carriage rate in healthy hospital staff.

Method

A total of 278 S.aureus strains isolated from clinical specimens were tested for antimicrobial susceptibility and 30 anterior nares swabs from healthy hospital staff were screened for S.aureus organisms using standard methods.

Results:

High resistance was observed against ampicillin, penicillin and tetracycline. High sensitivity was recorded against amikasin, amoxicillin-c and ciprofloxacin. Of the 278 isolates 26 (9%) isolates were methicillin resistant S.aureus (MRSA). 17 % of the hospital staff were positive for nasal carriage of Staphylococcus aureus .

Conclusion:

Our study emphasizes the need for continuous monitoring of the antimicrobial susceptibility pattern of S.aureus isolates including MRSA for the selection of appropriate therapy. In Eritrea, from the present findings it appears that the spread of MRSA in community and hospital settings is limited.