Phenotypic Detection of Methicillin and Inducible Clindamycin Resistant Staphylococcus Aureus: An Effort to Combat Antimicrobial Resistance and Improve Patient Safety in Gombe, Nigeria

Introduction: Antimicrobial resistance (AMR) is a major threat to patient safety. Methicillin and inducible clindamycin resistant Staphylococcus aureus are important multidrug resistant organisms (MDROs). Timely reporting of MDROs is necessary for rational antibiotic prescription and in combating AMR. We present the prevalence and distribution of Methicillin and inducible clindamycin resistant (iCR) isolates of Staphylococcus aureus from Gombe Nigeria. Materials and Methods: This descriptive cross-sectional study included 260 isolates of Staphylococcus aureus from clinical specimens in Federal Teaching Hospital Gombe (FTHG). Isolates identification was done using conventional biochemical methods. Methicillin resistance was detected by cefoxitin disc diffusion method while iCR isolates by erythromycin and clindamycin disc approximation test (D-test). Data analysis was done using SPSS version 23.0. Results: Methicillin resistant Staphylococcus aureus (MRSA) was detected in 178 (68.5%) isolates while 214 (82.3%) were iCR (D-test positive). Among the MRSA, 87.1% were also iCR while 72.4% of the iCR isolates were MRSA. There was significant association between MRSA and iCR (p = 0.03), MRSA and clindamycin resistance (p = 0.05) and MRSA and erythromycin resistance (p < 0.01). Conclusion: Prevalence of MDR Staphylococcus aureus is high in Gombe Nigeria. Antimicrobial stewardship programme (ASP) and good Infection Prevention and Control (IPC) are necessary in combating AMR and improving patient safety.

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Fluoroquinolone- and Methicillin-Resistant Staphylococcus Aureus: Insights from the Antimicrobial Resistance Management Program

Journal of Pharmacy Technology ◽

10.1177/875512250502100302 ◽

2005 ◽

Vol 21 (3) ◽

pp. 123-128 ◽

Cited By ~ 2

Author(s):

John G Gums ◽

Benjamin J Epstein

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Methicillin Resistance ◽

Resistance Management ◽

Multidrug Resistant ◽

Management Program ◽

Methicillin Resistant ◽

The North ◽

The Us ◽

Northeast Us

Background: Staphylococcus aureus is a frequent cause of infections involving the bloodstream, skin and soft tissue, and lungs in hospitalized patients. These isolates are often multidrug resistant and represent a major therapeutic challenge. Objective: To explore the susceptibilities of S. aureus to nafcillin/oxacillin, a surrogate for methicillin resistance, and the fluoroquinolones and determine whether a relationship might exist between fluoroquinolone use and the prevalence of methicillin-resistant S. aureus (MRSA). Methods: To date, 353 institutions throughout the US and Puerto Rico have enrolled in the Antimicrobial Resistance Management (ARM) Program, and data have been submitted on nearly 5 million isolates of S. aureus. Isolates submitted from 1990 through 2002 were reviewed for sensitivity to nafcillin/oxacillin, clindamycin, erythromycin, and the fluoroquinolones ciprofloxacin and levofloxacin. Results: From 1990 through 2002 inclusive, susceptibility to nafcillin/oxacillin nationally was 64.9% (n = 360,460), ranging from 62.2% in the North Central and Northeast US to 72.8% in the Southwest. Nationally, S. aureus isolates were more resistant to levofloxacin (41.4%, n = 123,868) than ciprofloxacin (38.7%, n = 256,178). The greatest change in susceptibility of S. aureus to nafcillin/oxacillin and ciprofloxacin occurred concurrently from 1998 to 2002, which may implicate fluoroquinolone use with increasing rates of MRSA infection. Conclusions: Resistance to methicillin and the fluoroquinolones has increased in concert during the past 5 years. Collectively, data from the ARM Program, along with several other investigations, support a role of fluoroquinolone use in the emergence of MRSA. These observations, along with increasing resistance among gram-positive and gram-negative pathogens, underscore the need for judicious use of fluoroquinolones.

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Bacterial Etiology of Wound Exudates in Tertiary Care Cancer Patients and Antibiogram of the Isolates

Infectious Diseases Research and Treatment ◽

10.1177/1178633720952077 ◽

2020 ◽

Vol 13 ◽

pp. 117863372095207

Author(s):

Kiran Duwadi ◽

Sujan Khadka ◽

Sanjib Adhikari ◽

Sanjeep Sapkota ◽

Pabitra Shrestha

Keyword(s):

Staphylococcus Aureus ◽

Pathogenic Bacteria ◽

Methicillin Resistance ◽

Tertiary Care ◽

Antibiotic Sensitivity ◽

Cross Sectional Study ◽

Diffusion Method ◽

Disc Diffusion ◽

Biochemical Tests ◽

Cross Sectional

Introduction: Patients with malignancies frequently develop infections as a result of surgical procedures and fungating wounds leading to pus formation. This cross-sectional study was conducted to explore the bacteriological spectra of infections of various cancer sites and their antibiotic sensitivity patterns among the patients visiting minor operation theatre (OT) of B.P. Koirala Memorial Cancer Hospital (BPKMCH), Chitwan, Nepal. Methods: Over a period of 3 months from September to November 2018, a total of 183 wound exudates and pus samples were collected and analyzed by standard microbiological procedures. Isolates were identified based on the colony characters, Gram staining and an array of biochemical tests. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion technique according to criteria set by CLSI, 2016. Methicillin resistance in Staphylococcus aureus was tested with the help of cefoxitin using disc diffusion method. Results: Out of the 183 samples, 149 (81.4%) were culture positive. Among 13 different isolates identified, S. aureus (43.0%) was predominant followed by E. coli (14.0%). Higher incidence of bacteria was seen among the males (52.3%), in the age group 51 to 60 years (26.8%) and among the patients undergoing surgical intervention to deal with cancer (34.2%). The prevalence of wound infection was significantly affected by gender, age, and treatment regimen ( P < .01). Out of the total 68 S. aureus isolates, 38 (44.1%) were deemed as Methicillin-resistant Staphylococcus aureus (MRSA). Among the 158 isolates, 85 (53.8%) were multi-drug resistant (MDR). Cefepime was the most effective antibiotic for Gram positive isolates whereas both imipenem and meropenem were found to be equally more effective for Gram negative isolates. Conclusion: This study suggests that patients with malignancies harbor pathogenic bacteria; therefore, prudent use of antibiotics is essential to prevent the emergence of MDR pathogens.

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Change of the Frequency of Methicillin Resistance and Antibiogram Resistance Profile of Staphylococcus aureus within a Period of 15 Years

Türk Mikrobiyoloji Cemiyeti Dergisi ◽

10.5222/tmcd.2021.04706 ◽

2021 ◽

Author(s):

Kamuran Şanlı ◽

Selen Zeliha Mart Kömürcü ◽

Nilgün Kansak ◽

Rıza Adaleti

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Methicillin Resistance ◽

Erythromycin Resistance ◽

Resistance Profile ◽

Antimicrobial Resistance Profile ◽

Gentamicin Resistance ◽

Successful Control ◽

Mrsa Strains ◽

Hospital Acquired

Objective: The aim of this retrospective study was to evaluate the rate and antimicrobial resistance profile of community-acquired (CA) and hospital-acquired (HA) methicillin-resistant and sensitive Staphylococcus aureus (MRSA, MSSA) strains between 2004 and 2019. Method: Within the scope of the research, the rate of MRSA and MSSA and the change in antimicrobial resistance profile over time were investigated using two research data of 210 Staphylococcus aureus strains isolated in 2004, and 401 in 2019. Results: While any significant change was not seen in the rates of CA-MRSA (32.4%) and CA-MSSA (67.6%) in 2004, and of CA-MRSA (31.6%) and CA-MSSA (68.4%) in 2019, the prevalence of HA-MRSA decreased by 56.1% in 2004 and 30.7% in 2019 and of HA-MSSA increased by 43.9% in 2004 and 69.3% in 2019. No resistance to vancomycin and teikoplanin was observed in MRSA strains. Resistance of CA-MRSA against ciprofloxacin, levofloxacin, clindamycin and gentamicin decreased. In CA-MSSA an increase of penicillin resistance as well as a decrease in gentamicin resistance was observed. In resistance of HA-MRSA against ciprofloxacin, levofloxacin, erythromycin, clindamycin, gentamicin decreased. HA-Resistance of MSSA against fusidic acid increased and against ciprofloxacin and trimethoprim/sulfamethoxazole and erythromycin resistance decreased. Conclusion: It was found that the rate of HA-MRSA decreased during the given period of 15 years. Vancomycin or teicoplanin resistance was not observed in MRSA and MSSA. While against ciprofloxacin, levofloxacin, clindamycin, gentamicin decreased in both CA-MRSA and HA-MRSA. A closer follow-up of the prevalence and antimicrobial resistance profiles of these strains is of utmost importance for the successful control of the infections caused by MRSA and MSSA.

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Prevalence of Multidrug Resistant Staphylococcus aureus Isolated from Nasal Cavities of MOUAU Students

South Asian Journal of Research in Microbiology ◽

10.9734/sajrm/2021/v9i130201 ◽

2021 ◽

pp. 27-36

Author(s):

Onyinyechi J. Omaba ◽

Chukwuma G. Udensi ◽

Blessing C. Uwakwe ◽

Emmanuel K. Amanze ◽

Ifunaya M. Okoh

Keyword(s):

Staphylococcus Aureus ◽

Nasal Cavity ◽

Methicillin Resistance ◽

Nasal Carriage ◽

Drug Susceptibility ◽

Multidrug Resistant ◽

Diffusion Method ◽

Microbiological Techniques ◽

Alternative Choice ◽

High Level

Aim: To determine the prevalence of multidrug-resistant Staphylococcus aureus isolated from nasal cavity of MOUAU students. Methods: The nasal specimens were evaluated using standard microbiological techniques and methicillin resistance test was checked for all isolates of Staphylococcus species by the disc diffusion method. Results: A total of Eleven (11) Staphylococcus aureus isolates were obtained from forty (40) nasal samples of MOUAU students i.e. four (4) from female and seven (7) from male. This study also showed that the highest number and percentage of Staphylococcus aureus isolates was observed in the male nasal samples 7(30.4%), while the lowest isolate was recorded in female nasal samples 4(23.5%). About 21(52.5%) of the 40 samples showed no traces of Staphylococcus specie. However, the drug susceptibility profile of bacterial isolate from nasal samples reveals varying percentage of sensitivity and resistance to the antibiotics. From this study, Ofloxacin (5 mcg) and Gentamicin (10 mcg) exhibited high percentage of sensitivity against the Staphylococus isolates at 10(90.9%) each. Cefuroxime (30 mcg) and Ceftazidime (30 mcg) showed high level of resistance against the Staphylococcus aureus isolates at 11(100%). No resistance to Ofloxacin (5 mcg) was noted. This study also revealed that 72.7% of Staphylococcus aureus isolates from the nasal cavity of healthy male and female students of Michael Okpara University of Agriculture, Umudike (MOUAU), showed multiple resistance to the antibiotics used. Conclusion: This study highlights the need to discourage the misuse of antibiotics and to implement strategies that could help eliminate of nasal carriage of Staphylococcus aureus. This will help to prevent severe Staphylococcus aureus infections in our environments. Also, it was report that Ofloxacin (5 mcg) and Gentamicin (10 mcg) antibiotics could be an alternative choice to use and to control MRSA infection as an effective antibacterial agent.

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Antimicrobial Resistance and the Spectrum of Pathogens in Dental and Oral-Maxillofacial Infections in Hospitals and Dental Practices in Germany

Frontiers in Microbiology ◽

10.3389/fmicb.2021.676108 ◽

2021 ◽

Vol 12 ◽

Author(s):

Annika Meinen ◽

Annicka Reuss ◽

Niklas Willrich ◽

Marcel Feig ◽

Ines Noll ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Methicillin Resistance ◽

Carbapenem Resistance ◽

Control Measures ◽

Clinical Isolates ◽

Infection Prevention And Control ◽

Odontogenic Infections ◽

Hospital Patients ◽

Dental Practices

Data on microbiological profiles in odontogenic infections are scarce. This study aimed to analyze the spectrum of pathogens and antimicrobial resistance in clinical isolates from dental and oral-maxillofacial clinical settings in Germany. We analyzed 20,645 clinical isolates (dental practices: n = 5,733; hospitals: n = 14,912) from patients with odontogenic infections using data (2012–2019) from the German Antimicrobial-Resistance-Surveillance (ARS) system. A total of 224 different species from 73 genera were found in clinical isolates from dental practices, and 329 different species from 97 genera were identified in isolates from hospital patients. In both hospitals and dental practices Streptococcus spp. (33 and 36%, respectively) and Staphylococcus spp. (21 and 12%, respectively) were the most frequently isolated microorganisms. In Streptococcus spp. isolates from hospitals, penicillin and aminopenicillin resistance proportions were 8.0% (95%CI 4.7–14.9%) and 6.9% (95%CI 4.7–9.9%), respectively. Substantially lower resistance proportions of penicillin and aminopenicillin were observed in dental practices [2.6% (95%CI 1.4–4.7%) and 2.1% (95%CI 1.1–4.0%), respectively]. Among Staphylococcus aureus isolates from hospital patients methicillin resistance proportions were 12.0% (95%CI 9.7–14.8%), which was higher than in isolates from dental practices (5.8% (95%CI 4.1–8.1%)]. High clindamycin and macrolide resistance proportions (>17%) were observed in Streptococcus spp. and Staphylococcus aureus isolates. In Klebsiella spp. isolates carbapenem resistance proportions were <1%. In sum, substantial antibiotic resistance was observed in isolates from odontogenic infections, which calls for strengthened efforts in antibiotic stewardship and infection prevention and control measures in both hospitals and dental practices.

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Prevalence of and risk factors for methicillin-resistant Staphylococcus aureus nasal carriage in the West of Iran: a population-based cross-sectional study

BMC Infectious Diseases ◽

10.1186/s12879-019-4567-1 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 3

Author(s):

Elham Ahmadi ◽

Mohammad Khojasteh ◽

Seyed Mohammad Mortazavi ◽

Fatemeh Khan-Mohammadi ◽

Ali Kazemnia ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistance ◽

Pcr Amplification ◽

Nasal Carriage ◽

Health Concern ◽

Diffusion Method ◽

The West ◽

Cross Sectional ◽

Disk Diffusion Test ◽

Methicillin Resistant

Abstract Background Several reports designate the recent increase in community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) nasal carriage. Because of the scanty information regarding the nasal carriage sate of MRSA in the west of Iran, the purpose of the present study was to determine the frequency of CA-MRSA in Sanandaj city. Methods Swabs collected from anterior nares of 600 volunteers were analyzed for the presence of S. aureus. The isolates were further investigated for methicillin resistance by using the cefoxitin disk diffusion test, followed by PCR-amplification of the mecA gene. SCCmec types and the presence of the Panton-Valentine Leukocidin (pvl) encoding genes were determined through PCR. Finally, the antimicrobial susceptibility of the isolates was determined by the agar diffusion method. Results Nasal screening identified 181 S. aureus, of which 55 isolates were MRSA. SCCmec types IV and V were detected in MRSA at frequencies of 80 and 20%, respectively. The overall frequency of pvl genes among the MRSA isolates was 14.54%. MRSA isolates were highly susceptible (98.18%) to mupirocin, gentamicin, and fusidic acid. Conclusions The high prevalence of CA-MRSA carriage in the population could pose a serious public health concern for the region. Additionally, advent of drug-resistant pvl-positive strains demands continuous surveillance on the colonization state of CA-MRSA in order to prevent dissemination of the bacterium in the community.

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Methicillin- and Inducible Clindamycin-ResistantStaphylococcus aureusamong Patients with Wound Infection Attending Arba Minch Hospital, South Ethiopia

International Journal of Microbiology ◽

10.1155/2019/2965490 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Mohammedaman Mama ◽

Addis Aklilu ◽

Kassahun Misgna ◽

Molla Tadesse ◽

Eyerusalem Alemayehu

Keyword(s):

Staphylococcus Aureus ◽

Wound Infection ◽

Methicillin Resistance ◽

Demographic Data ◽

Cross Sectional Study ◽

Diffusion Method ◽

Cross Sectional ◽

Methicillin Resistant ◽

Inducible Clindamycin Resistance ◽

Antimicrobial Susceptibility Pattern

Background. Wound infection is one of the most common hospital-acquired infections. Different bacteria cause infection, of whichStaphylococcus aureusis one of the known bacteria in causing infection with increased drug-resistant isolates.Objective. To assess the prevalence and antimicrobial susceptibility pattern of methicillin and inducible clindamycin-resistantStaphylococcus aureusamong patients with wound infections attending Arba Minch Hospital.Methods. A facility-based cross-sectional study was conducted from April to June 2017. A pretested questionnaire was used to collect demographic data and clinical characteristics. Wound swabs were cultured and identified by standard techniques. Antibiotic susceptibility tests were performed by the Kirby–Bauer disc diffusion method. Methicillin resistance was detected using the cefoxitin (30 μg) antibiotic disc while inducible clindamycin resistance was detected by the D-zone test. The data were analyzed using Statistical Package for Social Science, version 20.pvalue <0.05 was considered statistically significant.Results. A total of 161 patients were enrolled and a majority of them were female (90, 50.9%). Among the collected samples, 79 (49.7%) were positive forS. aureus; of this, methicillin resistance accounted for 65 (82.3%). Out of 22 (27.8%) erythromycin-resistant isolates, 19 (24.1%) showed inducible clindamycin resistance. Methicillin-resistantS. aureusshowed higher resistance against tetracycline (72.3%) followed by cotrimoxazole (43.1%) and 100% sensitivity to vancomycin. The overall prevalence of inducible clindamycin resistance among methicillin-resistant isolates was 16 (24.6%).Conclusion. The increasing prevalence of methicillin-resistantS. aureusand the coresistance against other therapeutic options like clindamycin is becoming an obstacle in the treatment of infections which need attention from concerned bodies.

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Emergence of CC8/ST239- SCCmec III/t421 tigecycline resistant and CC/ST22-SCCmec IV/t790 vancomycin resistant Staphylococcus aureus strains isolated from wound: A two-year multi-center study in Tehran, Iran

Acta Microbiologica et Immunologica Hungarica ◽

10.1556/030.2021.01534 ◽

2021 ◽

Keyword(s):

Staphylococcus Aureus ◽

Acquired Resistance ◽

Multidrug Resistant ◽

Diffusion Method ◽

Resistance Pattern ◽

Disk Diffusion Method ◽

Cross Sectional ◽

Phenotypic Resistance ◽

Multiplex Pcr Assay ◽

Vancomycin Resistant

Abstract Staphylococcus aureus as an opportunistic bacterial pathogen with intrinsic and acquired resistance to many antibiotics is a worldwide problem. The current study was undertaken to evaluate the resistance pattern, and determine the genetic types of multidrug-resistant S. aureus isolated from wound. This cross-sectional study was conducted over the period of two years (from December 2018 to November 2020) at the hospitals affiliated to Shahid Beheshti University of Medical Sciences, Tehran, Iran. In present study, 75 multidrug-resistant S. aureus isolates collected from wound infections were investigated. Phenotypic resistance was assessed by Kirby–Bauer disk diffusion method. Conventional PCR was performed for the detection of virulence encoding genes. Genotyping of strains was performed based on coa gene polymorphism using multiplex-PCR assay. SCCmec typing, spa typing and MLST were also used to characterize the genotype of the mupirocin, tigecycline and vancomycin resistant multidrug-resistant S. aureus isolates. All 75 multidrug-resistant S. aureus isolates in the study were confirmed as MRSA. Coagulase typing distinguished isolates into five genotypic patterns including III (40%), I (24%), IVb (16%), V (10.7%) and type X (9.3%). Resistance to tigecycline was detected in 4% of MDR-MRSA isolates and all belonged to CC8/ST239- SCCmec III/t421 lineage. According to our analysis, one VRSA strain was identified that belonged to coa type V and CC/ST22-SCCmec IV/t790 lineage. Resistance to mupirocin was detected in 9.3% of strains. All 7 mupirocin resistant MDR-MRSA isolates exhibited resistance to mupirocin in high level. Of these, 4 isolates belonged to CC/ST8-SCCmec IV/t008 (57.1%), 2 isolates belonged to CC/ST8-SCCmec IV/t064 (28.6%) and one isolate to CC/ST22-SCCmec IV/t790 (14.3%). Altogether, current survey provides a snapshot of the characteristics of S. aureus strains isolated from patients. Our observations highlighted type III as predominant coa type among multidrug-resistant MDR strains indicating low heterogeneity of these isolates. Our study also indicates the importance of continuous monitoring of the genotypes of MDR-MRSA isolates to prevent nosocomial outbreaks and the spread of MDR isolates.

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Prevalence of Methicillin-Resistant Staphylococcus aureus Isolated from Clinical Samples at Narayani Samudayik Hospital, Chitwan, Nepal

Tribhuvan University Journal of Microbiology ◽

10.3126/tujm.v7i0.33794 ◽

2020 ◽

Vol 7 ◽

pp. 37-42

Author(s):

Rama Adhikari ◽

Bindu Kshetri ◽

Khem Narayan Sharma ◽

Santosh Khanal ◽

Om Prakash Panta ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Susceptibility ◽

Methicillin Resistance ◽

Diffusion Method ◽

Clinical Samples ◽

Susceptibility Pattern ◽

Cross Sectional ◽

Mannitol Salt Agar ◽

Antibiotic Susceptibility Pattern ◽

Clinical Specimens

Objectives: The main objective of this study was to determine the prevalence of Methicillin Resistance Staphylococcus aureus (MRSA) and MDR bacteria isolated from various clinical specimens from the patients attending Narayani Samudayik Hospital, Chitwan Methods: A cross sectional study was carried in NPI-Narayani Samudayik Hospital, Chitwan from June to December 2017. Altogether, 3610 clinical specimens mainly pus, blood and urine were collected, streaked on Mannitol Salt Agar and Blood Agar and incubated at 37°C for 24 hours. The confirmed colonies of S. aureus were sub-cultured on Nutrient Agar. The antibiotic susceptibility pattern of all isolates S. aureus was determined by Kirby Bauer disc diffusion method. Isolates resistant to cefoxitin (30mcg) were confirmed as MRSA. Result: Among 3610 total clinical samples, 17.6 % (635/3610) showed growth and 95(14.96%) S. aureus were isolated. Higher number of S. aureus was isolated from pus sample (93.15%). Out of 95 S. aureus isolates, 55 (57.89%) were identified as MRSA while 40 (42.10%) were MSSA. Vancomycin, ceftriaxone and chloramphenicol were found to be most effective antibiotic against isolates. Whereas, the least effective antibiotic was cefoxitin followed by amoxiclav, oxacillin and amoxicillin. Conclusion: This study concludes that the overall prevalence of MRSA and MDR among the bacterial isolates is higher compared to other studies. So, it is recommended to monitor the antibiotic susceptibility pattern of pathogens regularly and study the epidemiology of such isolates.

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Biofilm Formation and Methicillin Resistance of Staphylococcus aureus Isolated from Clinical Samples

The International Arabic Journal of Antimicrobial Agents ◽

10.3823/841 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Abdelraouf A. Elmanama ◽

Islam Majdi Al-Aydi ◽

Mariam R. Al-Reefi

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Biofilm Formation ◽

Antimicrobial Agents ◽

Methicillin Resistance ◽

Gaza Strip ◽

Diffusion Method ◽

Clinical Samples ◽

Disk Diffusion Method ◽

High Tendency

Background: Staphylococcus aureus including methicillin resistant S. aureus (MRSA) is one of the most effective biofilm-forming organisms, biofilm contribute in protecting the microorganism from host defenses and prevent the effective penetration of antimicrobial agents. Biofilm formation is considered as an important contributing factor for the initiation and establishment of chronic infection by S. aureus and known as a major obstacle in the treatment of S. aureus infections is their ability to develop resistance to antimicrobials. Aims : To screen clinical Staphylococcus aureus including MRSA isolates for their biofilm forming abilities and their association with antimicrobial resistance. Methods: A total of 196 clinical isolates of S. aureus were obtained from different sample sources using standard microbiological techniques from three major hospitals in Gaza strip. Biofilm formation of these isolates was determined by tissue culture plate (TCP) method and tube adherence method (TM). Antimicrobial susceptibility test was performed using the modified Kirby–Bauer disk diffusion method as per Clinical and Laboratory Standards Institute guidelines. MRSA was detected using the cefoxitin disk test. Results: Biofilm formation was observed in 174 (88.8 %) and in 145 (74.0%) isolates of S. aureus via TCP method and TM, respectively. The highest resistance percent was for penicillin (92.9%), followed by cefoxitin (80.6%) and oxacillin (67.9%), while the lowest resistance percent was for linezolid and ceftaroline (1%). Among the 196 isolates 71.4% (N=140) were classified as MDR with a MAR index (≥ 0.2). A total of 158 isolates (80.6%) were identified as MRSA distributed as 90.4%, 79.4% and 70.9% from Al-Shifa, Al-Nasser pediatrics and Al-Aqsa hospitals respectively. Large proportions (82.1%) of biofilm producers were identified as MRSA. Biofilm-producing MRSA exhibited a higher percent (90.5%) when compared with the biofilm non-producer MRSA (9.5%). Importantly, 89.2% of biofilm-producing S. aureus were multidrug resistant. Conclusions: S. aureus isolates possessed high biofilm-forming ability. Biofilm-producing strains have very high tendency to exhibit antimicrobial resistance, multidrug resistance and methicillin resistance. Regular surveillance of biofilm formation by S. aureus and their antimicrobial resistance profile may lead more success in treating S. aureus infections. Keywords: Biofilm, MDR, MRSA, TCP, TM, Gaza strip, Palestine.

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