Prevalence and genetic characteristics of fusidic acid resistant Staphylococcus aureus clinical isolates: Emergence of t030 strains carrying fusB in Tehran, Iran.

The literature on fusidic acid resistant Staphylococcus aureus strains is scarce in Iran, although the emergence of these strains in health care settings is increasing. This descriptive cross-sectional study was conducted on 68 fusidic acid resistant S. aureus strains to learn about the molecular characteristics and antimicrobial resistance of strains isolated from hospitalized patients. In the present study, the prevalence of resistance to fusidic acid in S. aureus isolates was 15.1%. Fusidic acid resistance determinative factors (fusB, fusC and fusD) were identified by multiplex PCR assay. To detect the existence of fusA and fusE determinants and their mutation status, amplifications and sequencing were performed. Molecular characterization of fusidic acid resistant isolates was investigated by SCCmec and spa typing methods. All strains were MRSA and multi drug resistant. Two (2.9%) and 31 (45.6%) isolates were resistant to vancomycin and mupirocin respectively. The SCCmec type IV was highly prevalent representing 50% followed by types III (51.5%), and SCCmec types II (13.2%). fusB, was the most predominant acquired gene (66.2%) followed by fusC (19.1%), and fusA (14.7%). The mutations in fusA were present in 10 isolates with 5 (50%) having L461K mutation showing fusidic acid MIC values of ≥256 µg ml-1 followed by H457Y (40%), and H457Q (10%) showing fusidic acid MIC values of 128 and 64 µg ml-1 respectively. Isolates were allocated to ten particular t030 (22.1%), t037 (14.6%), t408 (11.8%), t064 (11.8%), t008 (10.3%), t002 (8.8%), t005 (5.9%), t790 (5.9%), t318 (4.4%), and t018 (4.4%) spa types. fusA positive isolates were assigned to particular spa types t002 (60%), and t005 (40%). There may be be a spreading of fusidic acid resistance among MRSA, creating worrying public concern. This research notes the importance of adequate data of local prevalence of FA-resistant MRSA in Iran for taking appropriate measures to treat, control and reduce the incidence of these isolates.

Genetic diversity of Staphylococcus aureus isolated from ear infections in Iran: Emergence of CC8/ST239-SCCmec III as major genotype.

Increase in antibiotic resistance in Staphylococcus aureus isolated from ear infection is a serious public health problem. The objective of this investigation was to determine the antibacterial resistance profile and genetic variability of the S. aureus isolated from adult patients with otitis externa (OE) and otitis media (OM) infections, Tehran- Iran. The disk diffusion was employed to detect the susceptibility of 45 S. aureus strains. Biofilm production was evaluated by microtiter plate assay. Genetic diversity of the isolates was determined by staphylococcal cassette SCCmec, spa, and MLST techniques. Resistance to mupirocin and vancomycin were identified in 40 and 2.2% of isolates. Out of the 45 S. aureus isolates, 41 (91.2%) strains were considered as positive biofilm strains at different levels. According to our results, S. aureus isolated from OM (44.4%, 20/45) were including CC8/ST239-SCCmecIII corresponded to spa types t860, t030, t037, t234, t421 (70%, 14/20) and CC/ST30-SCCmecIV corresponded to spa types t605 and t019 (30%, 6/20) while S. aureus isolated from OE (55.6%, 25/45) were including CC/ST30-SCCmecIV corresponded to spa types t605, t345 and t1130 (52%, 13/25), CC/ST22-SCCmecIV corresponded to spa type t790 (20%, 5/25), CC8/ST8-SCCmecIV corresponded to spa type t008 (16%, 4/25), and CC/ST45-SCCmecIV corresponded to spa types t004 and t038 (12%, 3/25). This study highlighted genetic variability and strong biofilm formation ability among our isolates revealing its crucial role in enhancing the resistance of this bacteria to drugs. Thus, it is necessary to continue the epidemiological analysis to improve the control of ear infections related to S. aureus.

Phenotypic and genotypic characterization of Staphylococcus aureus strains isolated from otitis externa: Emergence of CC30-spa t019-SCCmec IV carrying PVL as major genotype.

The increasing emergence of Staphylococcus aureus as the primary causative agent of otitis externa has been noted; however, detailed information regarding the molecular characteristics of these strains in Iran remains scarce. The current study aims to investigate both genotypic and phenotypic attributes of S. aureus strains implicated in ear infections. In the present work, we analyzed 60 S. aureus strains isolated from cases of otitis externa over a period of 45 months. The resistance patterns were determined using disk diffusion and microbroth dilution methods. All S. aureus isolates were confirmed by the nucA polymerase chain reaction assay, and their biofilm production was assessed by a microtiter plate assay. Molecular characterization of the isolates was performed using the staphylococcal cassette chromosome mec, multilocus sequence typing, and staphylococcus protein A typing methods. Overall, the results indicated that 44 out of 60 S. aureus isolates (73.3 %) were methicillin-resistant Staphylococcus aureus. Resistance to mupirocin and vancomycin was observed in 13.3 % and 1.7 % of the tested isolates, respectively. Furthermore, out of the 60 S. aureus isolates, 56 strains (93.4 %) were classified as positive biofilm strains at different levels. Twelve distinct clonal lineages were identified. The vast majority of S. aureus isolates belonged to CC30/ST30-MRSA IV/t019 (41.7 %). Among the 31 strong biofilm producers, the majority (64.5 %) belonged to CC30/ST30-MRSA IV/t019 clone. Biofilm negative isolates belonged to CC22/ST22 (2 isolates), CC8/ST585 (one isolate), and CC8/ST8 (one isolate). Our result revealed that about three-quarters of PVL-positive strains belonged to CC30/ST30. Our data confirmed the presence of MSSA strains among CC30/ST30 and CC22/ST22 isolates. The mupirocin resistant isolates (n = 8) belonged to CC8/ST585-MRSA III/t713 (37.5 %), CC8/ST239-MRSA III/t030 (25 %), CC8/ST8-MRSA IV/t008 (12.5 %), CC8/ST239-MRSA III/t037 (12.5 %), and CC22/ST22-MRSA IV/t790 (12.5 %) lineages. The VRSA strain belonged to the CC8/ST8-MRSA IV/t008 lineage, carrying the vanA determinant. iMLSB phenotypes (n = 14) were distributed across different lineages, including CC30/ST30-MRSA IV/t019 (21.5 %), CC30/ST30-MSSA/t021 (21.5 %), CC22/ST22-MSSA/t005 (14.3 %), CC8/ST239-MRSA III/t030 (14.3 %), CC22/ST22-MSSA/t1869 (7.1 %), CC22/ST22-MRSA IV/t790 (7.1 %), CC8/ST239-MRSA III/t037 (7.1 %), and CC1/ST772-MRSA IV/t10795 (7.1 %). These findings highlight significant genotypic diversity and high biofilm formation among our isolates. The frequent occurrence of the CC/ST30 clone in S. aureus strains isolated from otitis externa reflects the emergence of these lineages as a predominant clone in Iran, posing a significant public health concern.

Fungal Infection in Co-infected Patients With COVID-19: An Overview of Case Reports/Case Series and Systematic Review.

Fungal co-infections are frequent in patients with coronavirus disease 2019 (COVID-19) and can affect patient outcomes and hamper therapeutic efforts. Nonetheless, few studies have investigated fungal co-infections in this population. This study was performed to assess the rate of fungal co-infection in patients with COVID-19 as a systematic review. EMBASE, MEDLINE, and Web of Science were searched considering broad-based search criteria associated with COVID-19 and fungal co-infection. We included case reports and case series studies, published in the English language from January 1, 2020 to November 30, 2021, that reported clinical features, diagnosis, and outcomes of fungal co-infection in patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Totally, 54 case reports and 17 case series were identified, and 181 patients (132 men, 47 women, and 2 not mentioned) co-infected with COVID-19 and fungal infection enrolled. The frequency of fungal co-infection among patients with COVID-19 was 49.7, 23.2, 19.8, 6.6, and 0.5% in Asia, America, Europe, Africa, and Australia, respectively. Diabetes (59.6%) and hypertension (35.9%) were found as the most considered comorbidities in COVID-19 patients with fungal infections. These patients mainly suffered from fever (40.8%), cough (30.3%), and dyspnea (23.7%). The most frequent findings in the laboratory results of patients and increase in C-reactive protein (CRP) (33.1%) and ferritin (18.2%), and lymphopenia (16%) were reported. The most common etiological agents of fungal infections were Aspergillus spp., Mucor spp., Rhizopus spp., and Candida spp. reported in study patients. The mortality rate was 54.6%, and the rate of discharged patients was 45.3%. Remdesivir and voriconazole were the most commonly used antiviral and antifungal agents for the treatment of patients. The global prevalence of COVID-19-related deaths is 6.6%. Our results showed that 54.6% of COVID-19 patients with fungal co-infections died. Thus, this study indicated that fungal co-infection and COVID-19 could increase mortality. Targeted policies should be considered to address this raised risk in the current pandemic. In addition, fungal infections are sometimes diagnosed late in patients with COVID-19, and the severity of the disease worsens, especially in patients with underlying conditions. Therefore, patients with fungal infections should be screened regularly during the COVID-19 pandemic to prevent the spread of the COVID-19 patients with fungal co-infection.