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Background and objectives: Chitosan is a preservative that is commonly used in food packaging due to forming a film with antimicrobial activity. Many antimicrobial agents have been used to control the growth of different bacteria, fungi and yeasts in food products using chitosan coating. The present research was conducted to examine inhibitory effects of a coating incorporated with the essential oils of Zataria multiflora (ZEO) and Bunium persicum (BEO) on the growth of Pseudomonas artificially inoculated onto salmon fillets over a period of 12 days at 4 °C.
Methods: The antibacterial activity of BEO against P. aeruginosa was evaluated using the microdilution method via determining minimum inhibitory concentration and minimum bactericidal concentration. For the food model investigation, three P. aeruginosa strains were inoculated onto trout fillets as culture cocktail to assess their survival over 12 days of storage.
Results: The results indicated that ZEO and BEO had stronger inhibitory effect on P. aeruginosa in trout fillets when applied along with gel type nano-emulsion of chitosan solution. The separate use of each of these substances also significantly inhibited the growth of these pathogenic bacteria compared with the control. In addition, the use of chitosan coating without any antimicrobial agent affected the growth of P. aeruginosa.
Conclusion: The gel type nano-emulsion of chitosan coating containing ZEO and BEO can be applied on foodstuff, particularly fish and its products, as an antimicrobial agent.

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Background: Klinefelter syndrome (KS) also known as 47, XXY is one of the most prevalent chromosomal abnormalities among men. Infertility is one of the most primary features of this condition. However, there are some other associated features such as thin and tall appearance, absent, delayed or incomplete puberty, small and firm testicles, small penis and gynecomastia.
Case description: We herein report a patient with mosaic KS whose karyotype consisted of 47, XXY/46, XY. The case’s wife had two miscarriages, followed by a healthy girl with a normal karyotype who was born taller than the average at the age of two.
Conclusion: Mosaic KS dramatically increases the chance of having healthy offspring with normal genetic patterns without performing artificial insemination methods compared to those with complete KS.

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Background and objectives: Different environmental factors, such as infection, can cause Alzheimer's disease (AD). Herpes simplex virus types 1 (HSV1) and 2 (HSV2) and cytomegalovirus (CMV) are related to AD. This study explores the potential role of HSV1, HSV2 and CMV in AD progression.
Methods: Plasma samples were taken from 100 AD patients (47 women and 53 men). After isolating viral DNA, PCR was performed using specific primers for the detection of the viruses.  
Results: The prevalence of CMV, HSV1 and HSV2 was 27%, 8% and 4%, respectively. Although CMV was most prevalent in AD patients, HSV1 and HSV2 were found in patients with advanced AD. The prevalence of HSV1 and HSV2 was significantly associated with dysphoria, hallucination, insomnia and depression (P˂0.05), while CMV was significantly associated with hallucination and dysphoria (P=0.001). AD symptoms were higher in patients with HSV1 and HSV2.
Conclusion: It seems that HSV and CMV infections may be related to the severity of AD. 

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Background and objectives: Antibiotic resistance is a major public health challenge. The pervasive antibiotic misuse can lead to increased antibiotic resistance. Thus, there is a need for discovery of new compounds against drug-resistant microorganisms. We synthesized new series of 1, 3, 4-oxadiazole derivatives (4a-4d) and evaluated the antibacterial and antifungal activity of the derivatives against Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumannii, Klebsiella pneumoniae, Aspergillus fumigatus and Aspergillus flavus.
Methods: The new derivatives of 1, 3, 4-oxadiazole were synthesized using a single-stage, high-yield method. The structure of the new compounds was confirmed by infrared spectroscopy, carbon-nuclear magnetic resonance and hydrogen- nuclear magnetic resonance. Then, antibacterial and antifungal activities of the prepared derivatives (1 mg/ml) were evaluated by determining minimum inhibitory concentration and minimum bactericidal/fungicidal concentration using the agar well diffusion method.
Results: All synthesized compounds, especially (4d) with methoxyphenyl group, exhibited powerful antibacterial activity against the tested bacteria. However, the compounds had no antifungal effect.
Conclusion: Our findings indicate the antibacterial potential of the novel synthetic 1, 3, 4-oxadiazole compounds.

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Background and objectives:  Safety is a key criterion for assessment of probiotics. The objective of this study was to evaluate safety of a new Iranian Lactobacillus paracasei IBRC-M 11110 strain as a candidate probiotic. 
Methods: Eighteen male and 18 female Wistar rats were divided into two experimental and a control group. The experimental groups received the bacterium at two doses of 6 × 10⁸ CFU/day and 6× 10⁹ CFU/day for 28 days through oral gavage. The control groups received normal saline. On day 29, blood, serum and tissue samples were taken for analysis.
Results: Administration of the bacterium did not affect the general health and body weight of the rats during the study period. No significant change was observed in the blood parameters of rats in the experimental groups except for a significant decrease in mean corpuscular volume and mean corpuscular hemoglobin of male rats. Serum analysis showed a significant increase in the alanine transaminase and a significant decrease in aspartate transaminase in the experimental groups of male and female rats, respectively. In both male and female rats, a significant decrease in urea and a significant increase in creatinine were observed in the experimental groups. However, the above parameters were all within the normal range. Histopathological analysis of liver and kidney tissues also showed no abnormality.
Conclusion: The results confirm that L. paracasei IBRC-M 11110 was safe in the subacute toxicity test in Wistar rats.

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Background and objectives: Medicinal plants have long been considered as one of the most important pillars of traditional medicine. Existing challenges in the treatment of diseases, particularly infectious diseases, are major drivers for herbal medicine studies. Tribulus terrestris has been widely used in traditional medicine to treat various diseases. This study aimed to investigate in vitro antibacterial effect of the aqueous extract of T. terrestris on several oral bacteria.

Methods: In this experimental study, after preparing the aqueous extract of T. terrestris, minimum inhibitory and bactericidal concentrations (MIC and MBC) of the extract were determined against standard strains of Streptococcus mutans, Staphylococcus aureus, Klebsiella pneumoniae and Streptococcus pyogenes using the broth microdilution method. The experiments were repeated three times and the results were analyzed with SPSS 22 using the one-way analysis of variance (ANOVA) and LSD statistical tests with the significance level set at 0.05.

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Background and objectives: Antibiotic resistance is a global health challenge that affects both individuals and the health system in many ways. The aim of this study was to evaluate the antibiotic resistance pattern in isolates from patients admitted to the intensive care unit (ICU) of a hospital in Qazvin, Iran.
Methods: This descriptive and retrospective study was performed on urine and blood samples collected from 1318 ICU patients in the Velayat Hospital of Qazvin (Iran) during 2017-2019. Data were collected from patients’ medical records. All statistical analyses were performed using SPSS software (version 25).
Results: Based on the findings, 65.2% of the samples were related to urinary tract infections and 34.7% to bloodstream infections. Escherichia coli (68.6%) and Stenotrophomonas (41.0%) were the most common bacteria isolated from urinary tract infections and bloodstream infections, respectively. Moreover, the rate of antibiotic resistance was higher among Acinetobacter, Escherichia coli, Stenotrophomonas, Enterococcus and Pseudomonas isolates.
Conclusion: The rate of drug resistance in isolates from ICU patients is alarmingly high and requires immediate attention. It is recommended to modify antibiotic prescriptions in the hospital based on the results of antibiotic resistance pattern, particularly for treatment of infections caused by E. coli and Stenotrophomonas.

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Infective endocarditis is rare in children but can cause significant morbidity and mortality. Streptococcus and Staphylococcus species are the leading causes of this disease. Staphylococcus is more common in people with underlying heart disease, and Streptococcus viridans is more common in people who have had a dental procedure. In general, any fever of unknown origin in children with an underlying heart problem should be carefully evaluated for endocarditis, and empiric therapy should be performed. The main symptoms of the disease include fever, new murmur, deterioration of the previous murmur, hematuria, embolic events, splenomegaly, bleeding splinter, Osler's nodes, Janeway lesion, and Roth spots. One of the important complications of infective endocarditis is cerebrovascular event and stroke. Herein, we describe a 6-year-old girl presented with fever and skin lesions and no history of underlying heart problem or dental procedure. The patient expired after three days of mitral valve infection with S. aureus.

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Background and objectives: Microscopic agglutination test is the gold standard sero-diagnostic method for detection of leptospirosis. Moreover, it helps identify serovars and their titers in serum samples. For obtaining accurate titer results, proper sampling, collection, storage, and transportation of samples are crucial while maintaining the cold chain. Since storage for long periods and the subsequent deterioration of samples may affect the final titers, we proposed an alternative method of MAT testing using filter paper-dried serum samples. We also evaluated sensitivity and specificity of the MAT test by using filtered-dried serum samples compared with the conventional MAT test.
Methods: This experimental study was performed on human and animal serum samples that were sent to a reference leprospirosis laboratory in 2020. Overall, 142 positive samples (with 289 titers for different strains) and 15 negative samples were used for MAT test using filtered-dried serum. For this purpose, each sample was dried on a filter paper (Whatman 903, GE Healthcare) at room temperature (20-30 °C) and kept for four days. On the fifth day, the filter papers were cut into small pieces, soaked in phosphate buffer saline, vortexed, and slowly mixed on shaker for two hours to elute antibodies. The MAT tests were performed simultaneously and under the same environmental conditions.
Results: The new MAT test using dried serum samples showed 79% sensitivity and 100% specificity. The test also had positive predictive value of 92% and negative predictive value of 24% when compared with the gold standard MAT test.
Conclusion: Filter-dried serum can be used for MAT test to overcome serum storage and transportation problems.

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Background and objectives: Bacterial contamination of wounds is a serious problem, particularly in burn patients. Gram-positive bacteria are the predominant cause of infection in newly hospitalized burn cases. This study aimed to survey the prevalence and antibiotic resistance pattern of gram-positive bacterial isolates among burn patients in Rasht, North of Iran.
Methods: This cross-sectional study was conducted on burn patients with a positive culture for gram-positive isolates who were hospitalized in the Velayat Burn Center in Rasht, North of Iran, during 2017-2020. The isolates were identified using standard microbiological methods. Moreover, the antibiotic resistance pattern was determined by the disk diffusion method.
Results: During the study period, 671 bacterial cultures were obtained, of which a total of 16 gram-positive isolates were taken from the patients. The frequency of coagulase-negative staphylococci (CoNS), Staphylococcus aureus, and Enterococcus spp. was 68.7%, 18.8%, and 12.5%, respectively. In addition, the highest rate of resistance in CoNS isolates was against trimethoprim/sulfamethoxazole. The highest rate of resistant among S. aureus isolates was recorded against penicillin. Moreover, Enterococcus faecalis isolates showed a high level of resistance to ampicillin, erythromycin, tetracycline, gentamicin, and ciprofloxacin. All isolates were susceptible to teicoplanin. Moreover, the frequency of methicillin-resistant S. aureus isolates was 66.7%.
Conclusion: Given the increasing prevalence of drug-resistant strains, especially in susceptible burn patients, it is imperative to analyze the bacterial etiology of nosocomial infections periodically and epidemiologically.

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Background and objectives: Garlic is a medicinal plant with various health promoting properties including antimicrobial effects. In this study, we investigated in vitro antibacterial effects of garlic hydro-alcoholic extract against enterohemorrhagic Escherichia coli (EHEC).
Methods: Garlic hydro-alcoholic extract was prepared by maceration method.  Phytochemical analysis of the extract was carried out using gas chromatography-mass spectrometry. Minimum inhibitory concentration (MIC) of the extract against EHEC was determined by micro-dilution assay. Cytotoxic effect of the garlic extract on human colon adenocarcinoma cell line (SW480) was assessed using MTT assay. Micro-dilution assay was also used to determine the MIC of the extract against EHEC when co-cultured with SW480 cells.
Results: The amount of organosulfur in garlic extract was 70.91% and the most common organosulfur compounds were trisulfide, di-2-propenyl (34.8%) and diallyl disulfide (14.83%). The MIC of garlic hydro-alcoholic extract on EHEC alone and when co-cultured with SW480 was 12.5 mg/ml. Concentrations of 12.5 mg/ml and 25 mg/ml of the extract significantly reduced the viability of SW480 cells compared to control and concentration of 6.25 mg/ml of garlic extract (p <0.0001).
Conclusion: The garlic hydro-alcoholic extract has inhibitory effects on EHEC in vitro. Therefore, it can be considered a suitable candidate for controlling infections caused by EHEC.

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Background and objectives: Neutralized electrolyzed water (NEW) is a novel natural disinfectant. It has been suggested that application of NEW can improve the shelf life of fish. This study aimed to investigate effect of NEW incorporated in alginate coating on growth of Escherichia coli O₁₅₇: H₇ on salmon fillets over a period of 12 days.
Methods: Fish fillets were inoculated with E. coli O₁₅₇:H₇ and divided into six different treatment groups: control (no coating), distilled water, alginate, EW, EW & alginate (Samples coated with alginate solution prepared by EW), and EW+ alginate (samples immersed in EW, then coated with alginate solution). The fillets were kept at 4 °C, and the bacterial count was determined on days: 0, 2, 4, 8, and 12. Data analysis was performed using repeated ANOVA and Bonferroni post-hoctest at statistical significance of 0.05.
Results: Treatment with alginate coating and EW alone could significantly reduce E. coli O₁₅₇: H₇ count on the salmon fillets. However, maximum reduction (1.27 log CFU/g) of bacteria was achieved when using alginate coating combined with EW.
Conclusion: According to the results, the combination of alginate coating with EW can be applied as a natural antimicrobial for increasing safety of food products, especially fish, against pathogenic bacteria such as E. coli O157: H7.

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Background and objectives: Recycled polyethylene terephthalate (RPET) nanofibers have become an important part of human life, with a continuous increase in their production and consumption. Herein, the antibacterial activity of nickel nanoparticles/recycled polyethylene terephthalate nanofibers (NiNP/RPET NF web) was evaluated by analyzing alginate expression in Pseudomonas aeruginosa, as an opportunistic microorganism.
Methods: NiNPs were synthesized and NiNP/RPET NF was produced by adding 25 μg/ml of NiNP to 10% solutions of RPET at a weight ratio of 3%. After exposing P. aeruginosa (PA01) to NiNP/RPET NF, the biofilm-forming capacity was determined and real-time PCR was performed to measure algD expression.
Results: Treatment with 25 μg/ml of NiNP/RPET NF reduced growth of P. aeruginosa on Mueller Hinton agar but did not result in complete inhibition. The biofilm optical density (550 nm) was 0.464 ± 0.021 after treatment with NiNP/RPET NF and 0.082± 0.011 in the absence of NiNP/RPET NF. This indicates the significant reduction of biofilm formation after exposure to NiNP/RPET NF (p=0.01). In addition, a 0.6-fold (p=0.03) reduction in alginate expression was detected by real-time quantitative real-time PCR.
Conclusion: Our results indicate the potential of NiNP/RPET NF for application in nano-based antibacterial medical systems.

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Background and objectives: Bacteriocins are generally active antimicrobial peptides effective against bacteria closely related to the producer. Escherichia coli produce two bacteriocins: colicins and microcins. Microcin J25 (Mcc J25) is an antibacterial peptide that inhibits bacterial transcription by disrupting the nucleotide-uptake channel of bacterial RNA polymerase. The objective of this study was to evaluate antimicrobial activity of MccJ25 produced by the bacteriocinogenic E. coli.
Methods: In this experimental study, 120 clinical specimens were selected from private diagnostic laboratories in Isfahan (Iran) in 2020. Antagonistic activity of isolates was tested by adopting agar plug method. Total DNA was extracted from clinical specimens and polymerase chain reaction (PCR) was performed using specific primers for amplification of the complete sequence of MccJ25 gene. Accuracy of the PCR products was confirmed by direct sequencing. Homology analysis was performed by using BLAST. Data were analyzed with Chromasv2.1.1 software.
Results: Overall, 120 E. coli strains were isolated from the clinical specimens. The antibiotic activity of Mcc J25 was mainly directed at Enterobacteriaceae, including several pathogenic E. coli strains of which 25 had positive well test samples, and about 5 (20%) of the collected clinical samples that were infected with E. coli had the MccJ25 gene.
Conclusions: Based on the results, Mcc J25 has favorable antibacterial potential, which can be further exploited as an alternative to chemical antibiotics.

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Background and objectives: Aflatoxin B1 (AFB1) is the most toxic aflatoxin produced by a large number of Aspergillus species. Successful detoxification of this toxin is an important attempt to improve community health. The aim of this study was to evaluate reducing effects of yeasts isolates from kefir and traditional kefir-like fermented beverages on AFB1 in a broth medium.
Methods: Polymerase chain reaction-sequencing was carried out to identify the yeast isolates from kefir and kefir-like beverages. Effects of the isolates on AFB1 adsorption and biotransformation in peptone dexterose broth medium were evaluated by using high performance liquid chromatography.
Results: Saccharomyces cerevisiae and Kluyveromyces marxianus were isolated from kefir and kefir-like beverages and resulted in 46% and 53% AFB1 adsorption, respectively. The isolates 27Y and 2Y caused 7% toxin biotransformation, while 10% toxin biotransformation was achieved by the isolate 18Y. 
Conclusion: Our results indicate that the yeast isolates from kefir and traditional kefir-like products can bind to and detoxify AFB1, thereby reducing its harmful effects.

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Background and objectives: Enterococcus faecium is a normal flora of gut microbiota. This opportunistic pathogen has attracted much attention due to its multidrug resistance and ability to survive in hostile environments. Various molecular typing methods such as pulsed-field gel electrophoresis or ribotyping have been developed for clinical and epidemiological investigation of these bacteria. However, these methods are time-consuming and labor-intensive. The present study was conducted to evaluate the discriminatory power of two common fingerprinting methods i.e. BOX-polymerase chain reaction (PCR) and enterobacterial repetitive intergenic consensus (ERIC)-PCR for E. faecium clinical isolates.
Methods: Fifty multidrug-resistant E. faecium isolates were isolated from 74 clinical specimens. The isolates were identified by specific 16S rRNA PCR. All isolates were fingerprinted using BOX-PCR and ERIC PCR. The discriminatory power and reproducibility of these two methods were also assessed.
Results: According to the dendrogram with >60% similarity, 17 different genotypes were observed using ERIC PCR. In addition, BOX-PCR produced 22 distinct patterns at a genetic distance percentage of 60%, with sizes ranging from 278 bp to 1450 bp. The discrimination index of BOX-PCR was higher than that of ERIC-PCR.
Conclusion: We concluded that a combination of ERIC-PCR and BOX-PCR may be a quicker and more reliable alternative for the discrimination of E. faecium clinical isolates.

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Background and objectives: Overuse and misuse of antibiotics in the agricultural and healthcare sectors have led to the emergence of antibiotic-resistant strains. Therefore, finding alternative antimicrobial compounds, such as phytochemicals, is of great importance. This study evaluated the feasibility of carvacrol as an antifungal agent in suppressing the planktonic and hyphal growth of clinical isolates of fluconazole-susceptible and -resistant Candida tropicalis.
Methods: Clinical isolates of fluconazole-resistant C. tropicalis were identified using the CLSI guidelines and the World Health Organization's WHONET software. The inhibitory effect of carvacrol on planktonic cells was assessed by determining the minimum inhibitory concentration (MIC) and time-kill profile. The inhibitory effect of carvacrol on hyphal growth was studied by using light field microscopy.
Results: The findings indicated that 50% of clinical isolates of C. tropicalis were resistant to fluconazole. The MIC90 and MIC50 of carvacrol against clinical isolates of fluconazole-susceptible and -resistant C. tropicalis were 25.00-300.00 µg/ml and 12.50-100.00 µg/ml, respectively. The time-kill analysis indicated that carvacrol exhibited fungicidal activity against the fluconazole-susceptible and -resistant C. tropicalis isolates 2-48 hours after exposure. Moreover, planktonic and hyphal growth of the isolates decreased significantly after exposure to carvacrol.
Conclusion: The findings revealed that carvacrol exhibits inhibitory effects on the planktonic and hyphal cells of fluconazole-susceptible and -resistant C. tropicalis isolates. Therefore, the antifungal potential of carvacrol as a natural antifungal could be further exploited for the treatment of resistant C. tropicalis infections

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Background and objectives: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease, caused by abnormal innate and adaptive immune responses. Anti-nuclear antibodies (ANA) and anti-double stranded DNA (anti-dsDNA) are reliable biomarkers for diagnosing SLE. Here, we aimed to investigate the serum levels of anti-dsDNA and ANA antibodies, their diagnostic utilities, and their relationship with disease activity and clinical/laboratory manifestations in patients with suspected.
Methods: We evaluated the plasma levels of ANA and anti-dsDNA antibodies in all individuals with suspected SLE (n=668) who had been referred to rheumatology clinics in Gorgan, Iran. The level of antibodies as well as C3, C4, and CH50 were determined using commercially available enzyme-linked immunosorbent assay kits.
Results: The mean level of ANA and anti-dsDNA antibodies differed significantly between the ANA-positive and ANA-negative groups (p<0.001). However, there was no significant difference in the mean values of C3 (p=0.233), C4 (p=0.415, and CH50 (p=0.482) between the two groups. Moreover, there was a significant positive correlation between ANA and anti-dsDNA levels (p<0.001, r=0.50).
Conclusion: Our findings indicate that anti-dsDNA levels are higher in ANA-positive individuals, and there may be a positive correlation between ANA and anti-dsDNA levels. It is recommended to evaluate the diagnostic and prognostic values of ANA and anti-dsDNA antibodies in future studies.

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Background and objectives: Foodborne pathogens can significantly affect the public health and cause medical, social, and economic burden. Listeria monocytogenes, Salmonella ­enterica, and Yersinia enterocolitica are important foodborne pathogens that can cause various diseases. Plant-derived compounds are promising bioactive substances with inhibitory effects against bacteria. Perovskia abrotanoides Kar. is a medical plant with broad therapeutic activities. In the present study, we aimed to investigate the inhibitory effects of P. abrotanoides extracts against some foodborne pathogens.
Methods: Flowering branches of P. abrotanoides were collected in 2018 and 2019 from three different habitats in the eastern Alborz Mountains, Iran. The antimicrobial activity of the extracts was evaluated using the agar well diffusion test. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts were determined against L. monocytogenes, S. ­enterica, and Y. enterocolitica. In addition, the antioxidant activity of the extracts was investigated by the DPPH test.
Results: The lowest MIC (200 µg/ml) and MBC (400 µg/ml) values against Y. enterocolitica were related to the ethyl acetate extract of plants collected from habitat 1 in 2019. The lowest MIC (50 µg/ml) and MBC (400 µg/ml) values against L.­­ monocytogenes were related to the dichloromethane extract of plants collected from habitat 1 in 2019. All extracts showed antioxidant properties. Results of one-way ANOVA indicated that the DPPH scavenging activity of extracts from plants collected in 2019 was greater than that of those collected in 2018. In most cases, the methanol and ethyl acetate extracts showed more radical scavenging potential.
Conclusion: It seems that P. abrotanoides is a rich source of antimicrobial and antioxidant compounds with great potential for use in the pharmaceutical and food industries.

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Background and objectives: Fluoroquinolones are a class of broad-spectrum antimicrobials typically used for the treatment of lower urinary tract infections. We aimed to determine the frequency of quinolone resistance genes in Klebsiella pneumoniae isolates from urinary tract infections in Guilan Province, Iran.
Methods: The resistance of 114 clinical isolates of K. pneumoniae to common fluoroquinolones and the minimum inhibitory concentration of ciprofloxacin were determined by disk diffusion and broth microdilution methods, respectively. Frequency of five plasmid-mediated quinolone resistance (PMQR) genes including qnrA, qnrB, qnrS, qepA, and aac (6')-Ib-cr was determined by PCR. 

Results. According to phenotypic assays, 60 isolates (52.6%) were resistant to at least one quinolone compound, 42 isolates (36.8%) were resistant to all tested quinolones, and 28 isolates (24.6%) showed a high level of ciprofloxacin resistance. In addition, aac(6')-Ib-cr was the most common PMQR gene (𝑛 = 44), followed by qnrS (𝑛 = 32), and qnrB (𝑛 = 21).
Conclusion: The possible dissemination of PMQR genes poses a serious threat to the management of infections by resistant Klebsiella pneumoniae.