RESUMEN
With the spread of multi-drug-resistant (MDR) bacteria and the lack of effective antibiotics to treat them, developing new therapeutic methods and strategies is essential. In this study, we evaluated the antibacterial and antibiofilm activity of different formulations composed of ibuprofen (IBP), acetylsalicylic acid (ASA), and dexamethasone sodium phosphate (DXP) in combination with ciprofloxacin (CIP), gentamicin (GEN), cefepime (FEP), imipenem (IPM), and meropenem (MEM) on clinical isolates of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) as well as the transcription levels of biofilm-associated genes in the presence of sub-MICs of IBP, ASA, and DXP. The minimal inhibitory concentrations (MICs), minimal biofilm inhibitory concentrations (MBICs), and minimum biofilm eradication concentrations (MBECs) of CIP, GEN, FEP, IPM, and MEM with/without sub-MICs of IBP (200 µg/mL), ASA (200 µg/mL), and DXP (500 µg/mL) for the clinical isolates were determined by the microbroth dilution method. Quantitative real-time-PCR (qPCR) was used to determine the expression levels of biofilm-related genes, including icaA in S. aureus and algD in P. aeruginosa at sub-MICs of IBP, ASA, and DXP. All S. aureus isolates were methicillin-resistant S. aureus (MRSA), and all P. aeruginosa were resistant to carbapenems. IBP decreased the levels of MIC, MBIC, and MBEC for all antibiotic agents in both clinical isolates, except for FEP among P. aeruginosa isolates. In MRSA isolates, ASA decreased the MICs of GEN, FEP, and IPM and the MBICs of IPM and MEM. In P. aeruginosa, ASA decreased the MICs of FEP, IPM, and MEM, the MBICs of FEP and MEM, and the MBEC of FEP. DXP increased the MICs of CIP, GEN, and FEP, and the MBICs of CIP, GEN, and FEP among both clinical isolates. The MBECs of CIP and FEP for MRSA isolates and the MBECs of CIP, GEN, and MEM among P. aeruginosa isolates increased in the presence of DXP. IBP and ASA at 200 µg/mL significantly decreased the transcription level of algD in P. aeruginosa, and IBP significantly decreased the transcription level of icaA in S. aureus. DXP at 500 µg/mL significantly increased the expression levels of algD and icaA genes in S. aureus and P. aeruginosa isolates, respectively. Our findings showed that the formulations containing ASA and IBP have significant effects on decreasing the MIC, MBIC, and MBEC levels of some antibiotics and can down-regulate the expression of biofilm-related genes such as icaA and algD. Therefore, NSAIDs represent appropriate candidates for the design of new antibacterial and antibiofilm therapeutic formulations.
RESUMEN
BACKGROUND AND OBJECTIVES: It is well known that Staphylococcus aureus biofilm plays an important role in adenoiditis and biofilm resistance frequently results in failure of therapy. The goal of this study was to evaluate the biofilm production of S. aureus isolates obtained from adenoid specimens and assess the relationship between biofilm formation ability and ica operon genes. MATERIALS AND METHODS: A total of 112 adenoid samples were obtained from patients under 15 years old with adenoid hypertrophy. All S. aureus isolates were initially identified by standard microbiological tests and amplification of nuc by polymerase chain reaction (PCR) technique. Biofilm formation of S. aureus isolates was evaluated and icaADBC genes were detected by PCR technique. RESULTS: There were 46 isolates (41%) identified as S. aureus. The ability to produce biofilm was detected among total S. aureus isolates. Molecular study of ica operon revealed that 2 (6.3%) and 19 (59.4%) isolates carried icaA and icaD, respectively. The prevalence of icaA + icaD was seen among 11 (34.4%) S. aureus isolates, while icaC and icaB were not detected. CONCLUSION: Our findings indicated that icaABCD operon are associated with biofilm formation in S. aureus isolates, however the absence of these genes may not necessarily exclude this property.
RESUMEN
OBJECTIVES: Escherichia coli is one of the most important causes of urinary tract infections (UTIs). The aim of this study was to determine antimicrobial resistance, resistance and virulence genes; phylogenetic groups and identify the epidemiologic features of uropathogenic E. coli (UPEC) isolates by multilocus sequence typing (MLST). MATERIALS AND METHODS: One hundred isolates of E. coli from inpatients with UTIs were collected in Kerman, Iran. Antimicrobial susceptibility testing, ESBLs, AmpC production and biofilm formation were performed by phenotypic methods. Phylogenetic groups, resistance and virulence genes were detected. Molecular typing of isolates was performed by MLST. RESULTS: In this study, 76% of isolates were multidrug-resistant. The bla CTX-M-15 and bla TEM were the dominant ESBL-encoding gene. Among 63 ciprofloxacin-resistant isolates, the frequency of qnrS (15.8%), qnrB (9.5%), and aac (6')-Ib (25% ) genes was shown. Fifty-five present of isolates were classified as week biofilm, (14%) moderate biofilm, and (5%) strong. The predominant phylogenetic group was B2 (3) . The prevalence of virulence genes ranged fimH (93%), iutA (66%), KpsmtII (59%), sat (39%), cnf (28%) and hlyA (27%). According to MLST results, 14 sequence types (ST) including ST-693, ST-90, ST-101, ST-1664, ST-2083, ST-131, ST-4443, ST-744, ST-361, ST-405, ST-922, ST-648, ST-5717and ST-410 were detected, indicating a high degree of genotypic diversity. CONCLUSION: We identified a high frequency of the ST131 clonal group among UTIs. These data show an important public health threat, and so further studies to control the dissemination and risk factors for acquisition of the ST131 clonal group and other STs are needed to make effective control.
