Status of Biofilm-Forming Genes among Jordanian Nasal Carriers of Methicillin-Sensitive and Methicillin-Resistant Staphylococcus aureus

Abstract

Introduction: Biofilm formation in Staphylococcus aureus is a major virulence factor. Both MSSA and MRSA are common causes of community-and hospital-acquired infections and are associated with biofilm formation. The status of biofilm-forming genes has not been explored in Jordanian nasal carriers of S. aureus. This study investigates antibiotic resistance patterns and the prevalence of biofilm-forming genes between MSSA and MRSA in two distinct populations in Jordan. Methods: A total of 35 MSSA and 22 MRSA isolates were recovered from hospitalized patients and medical students at Prince Hamzah Hospital, Jordan. Antibiotic susceptibility was tested using disk diffusion method and Vitek 2 system. The phenotypic biofilm formation was tested using CRA and microtiter plate assays. The prevalence of the biofilm-forming genes was determined using multiplex PCR. Results: Among 57 S. aureus isolates, 22 (38.6%) isolates were MRSA and were highly resistant against benzylpenicillin, oxacillin, and imipenem. The frequencies of the icaADBC were 77.1%, 97.1%, 94.3%, and 97.1% respectively in MSSA compared to 86.4%, 100%, 100%, and 100% in MRSA isolates. On the other hand, the frequency of the fnbA, fnbB, clfA, fib, clfB, ebps, eno, and cna genes was 81.8%, 90.9%, 95.5%, 90.9%, 86.4%, 100%, 100%, and 40.9%, respectively in the MRSA isolates. Conclusion: In both groups, MRSA isolates, in comparison to MSSA, were significantly more resistant to cefoxitin, oxacillin, imipenem, tetracycline, clindamycin, and trimethoprim-sulfamethoxazole. Unexpectedly, biofilm formation and gene prevalence between MRSA and MSSA isolates showed no significant difference, suggesting other potential virulence mechanisms.

Prevalence and Characteristics of Staphylococcus aureus Isolated From Retail Raw Milk in Northern Xinjiang, China

“…In addition, we found that most isolates (66.1%, 41/62) were strong biofilm-forming strains. However, the study of Khasawneh et al (2020) showed that the proportions of strong, medium, and weak biofilm forming strains among 57 S. aureus isolates were 12.3, 80.7, and 7.0%, respectively. Triveni et al (2018) reported that only 72 (38.3%) of the 188 strains of S. aureus were screened as biofilm producers, of which 34 (18.1%) were strong biofilm-forming strains and 38 (20.2%) were medium biofilm-forming strains.…”

Incidence of biofilm formation among MRSA and MSSA clinical isolates from hospitalized patients in Israel

“…Biofilm production is considered to be an important factor in S. aureus pathogenesis, antibiotics resistance, and immune evasion (Khasawneh et al, 2020). Biofilm‐forming S. aureus causes many diseases including endocarditis, septicemia, osteomyelitis, pneumonia, pleuropulmonary and device‐related infections (Lister & Horswill, 2014; Shivaee et al, 2019; Tong et al, 2015).…”

“…In this study, 83 MSSA and 80 MRSA samples isolated from different clinical sources were genetically and phenotypically characterized for biofilm formation. Biofilm production is usually genetically associated with the presence of elements of the ica ABCD operon (Cramton et al, 1999; Khasawneh et al, 2020; Knobloch et al, 2002; Rohde et al, 2001; Shivaee et al, 2019). While many studies have demonstrated ica ADBC frequencies of 77%–100%, most have not found a correlation between the presence of ica elements and biofilm formation phenotype (Cramton et al, 1999; Khasawneh et al, 2020; Knobloch et al, 2002; Rohde et al, 2001).…”

“…Biofilm production is usually genetically associated with the presence of elements of the ica ABCD operon (Cramton et al, 1999; Khasawneh et al, 2020; Knobloch et al, 2002; Rohde et al, 2001; Shivaee et al, 2019). While many studies have demonstrated ica ADBC frequencies of 77%–100%, most have not found a correlation between the presence of ica elements and biofilm formation phenotype (Cramton et al, 1999; Khasawneh et al, 2020; Knobloch et al, 2002; Rohde et al, 2001). In their characterization of 128 S. aureus isolates, Knobloch et al (2002) found all to be ica ‐positive using PCR methods, while none displayed a biofilm‐positive phenotype in the CRA assay, and only 4 (3.1%) were biofilm‐positive in the tissue culture plate (TCP) assay.…”

“…Another explanation for the varied incidence of ica in biofilm‐forming isolates between the different studies may be due to the inconsistent choice of primers for PCR analysis. Khasawneh et al (2020) and Arciola et al (2015) characterized 100% and 78%, respectively, of their tested isolates as biofilm‐forming using phenotypic assays, all of which were ica ‐positive. Overall, different phenotypic assays in conjunction with an inconsistent set of primers likely underlie the reported contradictory results relating to biofilm formation and its association with an ica genotype in S. aureus (Knobloch et al, 2002).…”