جستجوی مقالات مرتبط با کلیدواژه « مقاومت آنتی بیوتیکی » در نشریات گروه « علوم پایه »

Acinetobacter baumannii is the cause of a wide range of nosocomial infections. Antibiotic resistance of this organism is a major challenge worldwide. The aim of this study was to identify oxa and ndm genes by multiplex-PCR and to determine the pattern of antibiotic resistance.

This study was performed in a period of 8 months by collecting 25 bacterial plate isolates. Antibiotic susceptibility testing was performed on Müller Hinton agar medium by disk diffusion method. MPprimer software was used to design the primers. After data collection, the level of significance was assessed at P˂0.05 using SPSS 22.

Except for gentamicin, cefpime, ciprofloxacin and tobramycin, there is a significant relationship between resistance pattern and sensitivity. All A. baumannii isolates were sensitive to ceftazidime. Also, 20% of the isolates were resistant to imipenem, which are considered carbapenem-resistant isolates of A. baumannii. Of the 25 isolates studied, 5 isolates (20%) had oxa58 gene, 5 isolates (20%) had oxa23 gene and three isolates (12%) had ndm gene.

The high prevalence of antibiotic resistance genes in A. baumannii isolates emphasizes the need for a systematic program in the control and treatment of this pathogen and shows necessity for more attention from health centers in prescribing appropriate antibiotics. Multiplex PCR method is a sensitive and reliable method for rapid detection of resistance genes in A. baumannii isolates.

Urinary tract infections is one of the most common infectious diseases and E. coli is one of urinary tract infection the most important factor. The purpose of this investigation is prevalence of sul genes in E.coli isolated from urinary tract infectious in Shahrekord to form cross-sectional in 2013. Samples was prepared as sterile and in terms of urine tests, cultures and was studied. Investigation antimicrobial susceptibility was performed by disk diffusion method. As well as, for tracing Sul gene PCR reaction was performed in the presence of specific primers and the results was analyzed. In this study of 130 E. coli isolates studied 67 isolates (53/51%) resistance to co-trimoxazol was observed. The frequency of genes sul1, sul2 and sul3 was respectively 20/89%, 55/22% and 4/47%. In statistical analysis with chi-square test between to resistance sulfonamides and sul genes significant correlation was observed. The results showed that E. coli isolates are high resistant to sulfonamides that may be the indiscriminate use of these antibiotics.

Integrons play an essential role in spreading antibiotic resistance genes among Escherichia coli isolates. The aim of this study was to determine the prevalence of class 1 and 2 integrons amongst Escherichia coli isolates producing broad-spectrum beta-lactamases (ESBLs) in patients with urinary tract infections referred to Ahvaz teaching Hospital in 2017-2018. In this cross-sectional descriptive study, isolates were determined using conventional methods. Antibiotic susceptibility was measured by agar disc diffusion method. Production of ESBLs enzymes was measured via double disc method. Finally, presence of genes related to class 1 and 2 integrons was done using specific primers and Polymerase chain reaction method. Amongst 123 Escherichia coli ESBLs producing isolates the highest resistance was related to Cefotaxime, Ceftazidime, Cotrimoxazole and, Nalidixic acid, respectively, and the least resistance was related to Imipenem. About 84 (68.29%) isolates had multiple drug resistance (MDR). Additionally, 93 (75.60 %) isolates had class 1 integron and 11 (8.94 %) isolates had class 2 integron. There were no significant relationships between the presence of integrons and resistance to different antibiotics (p > 0.05). High prevalence of class 1 integron amongst Escherichia coli isolates producing broad-spectrum β-lactamase may contribute to resistance to common antibiotics. Therefore, identifying frequency of integrons and their relationship with drug resistance patterns seems to be necessary.

isolates of Staphylococcus aureus from different samples to determine antibiotic resistance and Staphylococcus aureus is a major cause of hospital acquired infections and community. Toxic shock syndrome toxin -1 gene secreted by the bacteria from the categories are important virulence factors and is component super antigens toxins pyrogenic (PTSAgs). The purpose of this study is determine the antibiotic resistance patterns and tsst-1 gene frequency in Staphylococcus aureus strains isolated from patients of Imam Khomeini hospital in Ahvaz. In this study, 133 clinical frequency tsst-1 gene were studied. After genomic DNA extraction using DNA extraction kit was performed the definitive diagnosis of bacteria, Then the gene tsst-1 frequency done in the presence of specific primers and antibiotic resistance was determined by agar disk diffusion method. After PCR amplification and detection of the bacterium, Of 133 isolates sequence tsst-1 gene was observed in 6 strains. In antibiogram test the greatest resistance to cefazolin (3/83%) and the lowest resistance to nitrofurantoin and vancomycin (0%) was observed. Due to the increasing prevalence of resistance to antibiotics of clinical importance tsst-1 gene timely identification and implementation of appropriate therapeutic strategies for controlling infection seems necessary.

Integrons are mobile genetic elements capable of carrying resistance genes to various antibiotics. These elements have been found in different places of plasmid and chromosome. The aim of this present study was determine the prevalence of class 1, 2 and 3 integrons in Escherichia coli isolates isolated from urinary tract infection in Shahrekord. In this research, the number of 64 isolates of Escherichia coli were investigated. The antibiotic resistance of the investigated isolates was evaluated using a simple disking method in Mueller Hinton agar medium. In order to determine the frequency of class 1, 2 and 3 integrons, specific primer pairs were used. After the antibiogram test, the highest resistance to ampicillin (75%) and the lowest resistance to imipenem (12.5%) were observed. The frequency of class 1, 2 and 3 integron genes was observed as 12.5%, 6.25% and 3.12%, respectively. None of the integron genes were observed in 52 isolates. In the statistical analysis with chi-square test, a statistically significant relationship was observed between class 1 integron and resistance to the antibiotic ampicillin (p = 0.02 < 0.05). Due to the fact that resistance genes are located on integrons and can be transferred from one strain to another strain and spread resistance in the hospital or other environments, this has doubled the importance of identifying this type of antibiotic resistance genes. Key words: Escherichia coli, integron, antibiotic resistance, urinary infection

Preventing the spread of drug resistance is one of the most important issues in society. Escherichia coli is one of the most common bacterial agents isolated from the urinary tract and nosocomial infections. Treatment of infections due to it is difficult due to the acquisition of resistance genes. This study aimed to investigate the phenotypic and genotypic pattern of antibiotic resistance in clinical uropathogenic strains isolated from diabetic patients.

A total of 51 E. coli isolates from urinary tract infection in diabetic patients obtained from clinical, were used in this study. Isolates were confirmed by chemical tests and molecular techniques based on tracking of the 16srRNA gene. Antimicrobial resistance assessment of isolates was done using molecular methods base on (qnrA, tet A, tet B, aac (3)IIa, sul1) and disk diffusion.

Most resistance r to ampicillin (66.66%) and the lowest resistance to Nitrofurantoin (1.96%) were reported. The frequency of tet A, tet B, qnr A, sul 1 and aac (3) IIa genes reported 68.62%, 64.7%, 29.41%, 39.21%, and 29.41% respectively. The statistical analysis shows a significant relationship between resistance to the antibiotic tetracycline and the gene tet A, tet B statistically.

Early detection of resistant strains to select the most appropriate treatment options is essential to prevent the spread of resistance. It is suggested, as treatment for urinary tract infections is important, so to prevent drug resistance and treatment failure, it should be done according to the resistance pattern in the region.

Listeria monocytogenes (L. monocytogenes) is a type of pathogenic bacteria that causes listeriosis infection. This facultative anaerobic bacterium is able to survive in the presence and absence of oxygen and is the cause of a wide range of diseases in humans and animals. Consumption of contaminated dairy products, meat and vegetables is the most important source of contamination. There are limited studies of the antibiotic resistance of Listeria monocytogenes species. Therefore, this study aims to evaluate the frequency and level of resistance in the evaluated samples. In this descriptive cross-sectional study, 150 different samples were randomly collected from different regions of Isfahan province. The samples included 60 samples of meat, 40 samples of dairy products (including milk, cheese, etc.) and 50 samples of vegetables (including leek, watercress, radish and basil). The serotyping of the isolated strains was done using the commercial O and H antisera of Listeria monocytogenes and according to the manufacturer's instructions, using slide agglutination method and antibiotic resistance evaluation. Standard PCR method was used to detect ermA, ermB, strA, tetS, tetA and ermC genes in the strains. Based on the serological reaction, somatic antigens O and flagella H of Listeria monocytogenes with the corresponding antisera, most Listeria species (70%) belong to serotype 1.2a and the rest from serotype 1.2b (19%) and 4b (11 %) They were. The results of the microbial investigation showed that the highest drug resistance was related to streptomycin (89%) and the lowest drug resistance in the evaluated isolates was related to ampicillin (14%) and chloramphenicol (13%). The most evaluated genes were related to strA gene and ermA gene, with frequencies of 79.8% and 65.4%, respectively. The prevalence of other Listeria monocytogenes genes evaluated in this study included tetA (17%), tetS (2.5%), ermB (10.7%) and ermC (2.1%).

Diabetes mellitus is a growing problem in today's modern societies. It is difficult to estimate the total number of people suffering from the disease. Approximately 20% of diabetic patients develop wound infections during their life Which in the absence of effective treatment can disrupt the quality of life of these people. On the other hand, treatment of this complication is very costly. DFIs diabetic foot infections are one of the most important public health issues and the identification of microorganisms that cause microbial infections An antibiotic is good for finding an appropriate treatment. Meanwhile, many reports have shown that antibiotic resistance is rising dramatically. Therefore, early diagnosis of lesions and the rapid onset of antimicrobial treatment are essential for controlling infection and preventing complications and improving the quality of life. An antibiotic susceptibility test is needed to manage infection, which can help in choosing the best treatment options.

Antibiotic resistance has been a known fact since the discovery of antibiotics, but in recent years, with the increase of resistant species and the decrease of effective and available antibiotics, it has become a worrying issue. Therefore, discovering or synthesizing new antibacterial agents plays a key role in solving the antibiotic resistance crisis. This study aimed to synthesize new derivatives of ciprofloxacin antibiotics to be more effective on ciprofloxacin-resistant bacteria.

A new series of thiourea and thiocarbamate derivatives of ciprofloxacin were synthesized and then the antibiogram test was performed by disk diffusion method on standard bacteria and clinically resistant bacteria. Also, the minimum inhibitory concentration and minimum bactericidal concentration of synthetic compounds were determined.

The results showed that all compounds S1-6 had antibacterial activity, and compound S4 was the most effective compound with an inhibition zone of 38 mm on P. aeruginosa ATCC 27853. The minimum inhibitory concentration of ciprofloxacin on E. coli ATCC 25922 is 50 μg/ml, while all the synthesized compounds have a minimum inhibitory concentration of less than 50 μg/ml, which indicates the high antibacterial activity of the synthetic compounds. In general, based on the obtained results, by adding different substituents and functional groups to ciprofloxacin, it is possible to synthesize new derivatives that are effective on resistant bacteria.

Pathogenic microorganisms are one of the important factors in contaminating and endangering the safety of foods for consumers, and continuous control of foods in terms of the presence of pathogenic microorganisms can guarantee the health of foods. Yersinia entrocolitica is a foodborne pathogenic bacterium. Raw milk and fresh traditional cheese may be contaminated with this bacterium. Generally, Iranians tend to consume traditional and homemade foods more than industrial products. This issue is especially relevant to milk products such as cheese, butter, and local cream. The purpose of this study was to determine the contamination of raw milk and traditional cheeses produced in Chaharmahal and Bakhtiari province with Yersinia entrocolotica.

A total, of 100 raw milk and 50 traditional cheese samples were obtained randomly from dairy plants and milk collection stations, as well as retail shops. The initial enrichment of the samples was performed in the TSB medium. Then, 100 microliters of the medium was centrifuged and 25 microliters of its sediment was cultured on the special medium of Cefsoludin Irgazan Novobiocin agar (CIN) with supplement (containing Cefsoludin 7.5 mg, Irgasan 0.2 mg and Novobiocin 1.25 mg). Suspicious colonies (red colonies) were identified on the CIN agar and biochemical tests including IMViC, Ureas, and H2S production.DNA extraction was performed by boiling method and polymerase chain reaction (PCR) was performed for the identification of Ali and Yst genes using specific primers (Table 1). Table 1. Characteristics of Primers Used to Identify Yersinia Enterocolitica Genes Antibiotic resistance test was performed by the disk diffusion method on Muller-Hinton agar according to the Clinical and Laboratory Standards Institute (CLSI). Resistance of Yersinia enterocolitica isolates to 7 commonly used antibiotics in treatment including cefixime (5µg), gentamicin (10µg), tryptoprim (5µg), ciprofloxacin (5µg), amoxicillin (10µg), tetracycline (30µg), and sulfamethoxazole (300µg).

Out of 100 samples of raw milk and 50 samples of traditional cheese, 20 samples (13.3%) suspected Yersinia enterocolitica bacteria were isolated. of these, 14 samples (14%) were related to raw milk samples and 6 samples (12%) were related to traditional cheese samples. The results of the PCR test showed that 5 isolates (3.3%) were Y. enterocolitica bacteria, 4 isolates (4%) related to raw milk, and 1 isolate (2%) related to traditional cheese. In addition, in the evaluation of virulence genes, it was found that out of 4 raw milk isolates, 1 isolate carried the Yst gene, 2 isolates carried the Ail gene, and 1 isolate had both genes. Also, 1 isolate of Y. enterocolitica isolated from traditional cheeses carried the Ail gene (Table 2). Table 2. Percentage of Contamination of Raw Milk and Traditional Cheese with Yersinia entrocolitica, (%) The results of antibiogram tests on Yersinia enterocolitica isolates showed the highest resistan.ce to Gentamicin, Trimethoprim, Ciprofloxacin, and Sulfamethoxazole antibiotics, and moderate resistance to cefixime and amoxicillin (Table 3).  Table 3. Antibiotic Resistance Pattern of Yersinia Entrocolitica Isolated from Raw Milk and Traditional Cheese.

In general, the results of the present study and other studies in Iran and the world show that raw milk and traditional cheeses, contaminated with Yersinia enterocolitica, which carry virulence genes and are resistant to some common antibiotics, can endanger the health of consumers.

The ability of Klebsiella pneumoniae as an opportunistic bacterium in hospital infections, by producing biofilm on food utensils and hospital surfaces, has adverse effects on the treatment and survival of hospitalized patients. The present study was conducted with the aim of investigating the effect of TiO2 nanoparticles on Klebsiella pneumoniae biofilm formation.

TiO2 nanoparticles were produced using sol-gel method. 62 strains of Klebsiella pneumoniae were isolated from three hospitals in Tehran. Antimicrobial activity of TiO2 nanoparticles against biofilm-producing and antibiotic-resistant strains was determined by disk diffusion method. Definitive identification of the isolates was done through common biochemical tests and 16S rRNA sequencing, and the expression of treC, mrkD, sugE, luxS and 16SrRNA genes was investigated by real time PCR.

The data showed that the ability to form biofilm among isolates obtained from sputum was higher than other isolates. TiO2 nanoparticles with a concentration of 256 μg/ml inhibited biofilm production in fourteen isolated strains. Comparison of LuxS gene expression in Klebsiella pneumoniae untreated and treated with TiO2 showed that the level of gene expression decreased by 3.85 times (p = 0.002).

This study showed that the synthesized TiO2 nanoparticles are effective against the formation of biofilm in Klebsiella pneumoniae strains resistant to several drugs and can be reliable and useful as inorganic antimicrobial agents.

Escherichia coli O157:H7 is one of the main foodborne pathogen that cause severe gastrointestinal issues and death. Cattle are the major reservoir for E. coli O157:H7. During the slaughtering process, E. coli O157:H7 enter to food chain. Identifying the source of contamination plays important role in the control of bacteria. The purpose of this study is molecular typing and determining of genetic relationships among E.coli O157:H7 isolates using RAPD-PCR technique and investigating the relationship between their genetic and antibiotic  resistance patterns.

The Random amplified polymorphic DNA (RAPD) analysis was used to evaluate genetic relationship among the isolates and the results was analyzed by NTSYSpc software. Antibiotic susceptibility of the isolates was examined through disc diffusion method.

The most isolates showed sensitivity to seven antibiotics and resistance were observed in six strains. DNA fingerprinting showed 10 genetic patterns. The isolates from different sources were clustered based on the similarity in RAPD pattern. The strains contain different DNA pattern and high genetic distance, showed different patterns of antibiotic susceptibility.

The genomic diversity showed distinct profiles of DNA in strains with the same clonal relationships and different patterns of antibiotic resistance were revealed. Therefor determining the clonal relationships of isolates with RAPD PCR technique, simultaneous using of antibiotic resistance patterns and molecular typing can be effective in detecting isolates and infection control.

Escherichia coli and Salmonella are gram-negative bacteria and are indicators of faecal contamination in food, and the presence of each of them in processed foods indicates lack of hygiene, and Staphylococcus aureus is a gram-negative bacteria. It is positive that it has the highest level of poisoning. The aim of the present study is to investigate the contamination with Staphylococcus aureus, Escherichia coli and Salmonella in cream sweets sold in Isfahan city and the antibiotic resistance of the obtained isolates. In this study, 120 cream sweets from the supply centers of this product in different parts of Isfahan city were randomly sampled and transferred to the specialized food hygiene laboratory of Shahrekord Azad University, next to the ice flask, in order to avoid secondary contamination. The standard method was used to search for microorganisms. The collected data was used in SPSS version 26 statistical software and chi-square test was used for data analysis. The results showed that Escherichia coli and Salmonella contamination was negative in all samples, but Staphylococcus aureus was confirmed in 4 cases of cream sweets. The samples were the most sensitive to tetracycline, streptomycin and amikacin and the most resistant to penicillin and ampicillin. In this survey, it was determined that a high percentage of the cream sweets offered in Isfahan city are in compliance with the existing standards in the society in terms of contamination and health quality to some extent, but in order to improve the health of the society,

Antibiotics are one of the largest groups of medicinal compounds that are used in medicine and veterinary medicine. These compounds, despite having positive effects in preventing and treating diseases in humans and animals, also have adverse effects on the environment. Recently, the indiscriminate use of antibiotics and the subsequent entry of these compounds into the environment have led to an increase in concerns at the global level. These compounds are not traditionally considered environmental pollutants, however, there are concerns about the emergence of these compounds in aquatic systems, due to their biological effects and potential risks to the environment and health. It is human. Conventional water and wastewater treatment processes are not designed to remove small amounts of chemicals such as antibiotics. Therefore, the entry of these compounds into the environment from different sources leads to the pollution of plants, animals, and water and soil environments and also creates problems for public health. In addition, the presence of these medicinal compounds in the environment leads to the development of antibiotic-resistant pathogens that potentially threaten the functioning of the ecosystem and human health. Then, the occurrence and the ways of their entry into the environment, as well as the negative effects of antibiotics on the environment and human health, were surveyed. Finally, the topics related to their fate and management and risk assessment of antibiotics in the environment were studied.

Infections caused by Staphylococcus aureus are on the rise due to the spread of resistant strains, an increase in immunocompromised patients, and the overuse of medical equipment. The bacterium is also an opportunistic pathogen that provides conditions for invading the host by producing and secreting various toxins, including various enterotoxins.The aim of this study was to evaluate the antibiotic resistance and frequency of sea gene in Staphylococcus aureus isolated from clinical sources in Karaj.
 

This descriptive-observational study was performed on 100 Staphylococcus aureus isolates collected from clinical sources in Karaj. Collected samples were transferred to the laboratory under appropriate conditions by culture, microscopic and biochemical methods and then the susceptibility of isolated bacteria to various antibiotics was measured by disk diffusion agar method according to CLSI (2019) instructions and finally to test production ability. Enterotoxin A, the presence of sea gene was assessed by PCR

Based on the results of biochemical tests, 100 isolates of Staphylococcus aureus were identified. According to the antibiogram test, these bacteria had the highest resistance to penicillin with 92% and ceftazidime with 82% and also 100% of the isolates were sensitive to vancomycin. The results of PCR reaction also showed that out of 100 isolates, 79% contained sea genes.

Considering the importance and role of Staphylococcus aureus in the pathogenesis and development of nosocomial infections, drug resistance and the presence and expression of enterotoxin genes in clinical specimens of this bacterium should be considered in disease control management.

Due to the widespread use of antimicrobials in veterinary medicine and the increase in livestock production, it seems that the risk of spreading antibiotic resistance in human societies is more related to animals and the veterinary field. In this study, antibiotic resistance and frequency of fimH, papC and sfa-foc virulence genes among Escherichia coli isolated from Caspian horse feces in Guilan were studied. In this cross- sectional study, E. coli isolates were isolated from the feces of 157 apparently healthy Caspian horses by culture method and biochemical tests. Resistance patterns against 17 different antibiotics were determined by disk diffusion method and frequency of virulence genes were assessed by PCR in isolates. In phenotypic assay of antibiotic resistance, the isolates showed the most resistance to streptomycin and sulfamethoxazole-trimetoprim antibiotics. Imipenem and gentamicin were the most effective antibiotics and 51.59 percent of isolates showed multi drug resistance pattern. The frequency of fimH, papC and sfa-foc virulence genes in isolates were 91%, 56.6% and 33.3%, respectively. Frequency of all of three investigated genes were significantly higher in MDR isolates (P< 0.05). The results of the present study indicate that Escherichia coli isolated from the feces of horses in Guilan has the potential to transmit antibiotic resistance and endanger public health.

Veterinary Antibiotics are widely used in Iran and elsewhere in the world to deal with livestock and poultry diseases, due to increased demand for meat and dairy products in the community. Most of these antibiotics are excreted in the urine and feces of livestock and poultry and these excrements are used as manure by farmers in fields and gardens. This issue has raised concerns about the release of antibiotics in the environment. Increasing the concentration of these compounds in agricultural environments may lead to antibiotic-resistant bacteria and genes, and ultimately affect the health of soil, plant, and humans.

In this article, a brief overview of the use of antibiotics in the world and Iran, ways to release it in the environment by livestock and poultry manure, its effect on the microbial community of the soil, the accumulation of antibiotics in the edible parts of plants and its impact on the health of human has been studied. Also, the effect of composting livestock and poultry manure before entering the fields and gardens as a suitable strategy to prevent the occurrence of these compounds into the soil has also been studied. Finally, existing research gaps and suggestions for a more accurate understanding of this issue in Iran has been declared.

Most Veterinary antibiotics added to agricultural land are absorbed by plant roots. This leads to their bioaccumulation in plant tissues and toxicity to plants. The type of treatments performed before the introduction of livestock manure into the field determines the final concentration of antibiotics introduced into the environment.

There are significant research gaps in the release of antibiotics into the environment. In Iran, the concentration of various antibiotics in manure and poultry as well as their fate in soil, plants and humans should be investigated.

Urinary tract infection is one of the most common and common bacterial infections, accounting for a significant proportion of hospital admissions (about 30-40%). Silver nanoparticles work by releasing silver ions against various bacteria. The fact that bacteria are not resistant to nanoparticles is very important and therefore will affect a wide range of bacteria.

In this study, 50 specimens of positive cultures with urinary tract infection referred to Imam Reza Hospital Laboratory in Bojnourd were studied. Resistance and susceptibility of the isolates were determined by disk diffusion method. In this study, antibacterial effects of silver nanoparticles were investigated by microdilution method using aqueous extract of Ganoderma leucidum. Vegetative electron microscopy was used to measure the size and shape of silver nanoparticles. In addition, infrared spectroscopy analysis was performed to investigate possible organic compounds involved in the synthesis of nanoparticles.

The highest antibiotic resistance was related to ampicillin (84%). The resulting nanoparticles were 20 to 45 nm in size.

The produced nanoparticles have antimicrobial activity and can be a good alternative in the treatment of antibiotic resistant infectious diseases.

 

Klebsiella pneumoniae (K. pneumoniae) is one of the important human pathogens among which emergence of antibiotic resistant results in many problems in therapeutic process. Class 1 integron genes may facilitate the conferring of antibiotic resistance among bacterial population. In the present study, isolation of K. pneumoniae from urine samples, determining the antibiotic resistant pattern, and evaluating the presence of class 1 integron genes were investigated.

The obtained isolated bacteria were confirmed via biochemical tests. Evaluating the bacterial resistance against 10 different antibiotics was performed by agar disk diffusion method and antibiotic resistant pattern was also determined. PCR method was used in order to detect the presence of class 1 integron genes among isolates.

80 K. pneumoniae were isolated from the urine sample of attendees of clinical laboratories in Karaj. Meropenem and Nitrofurantoin were the most and least effective antibiotics, respectively. 16 isolates were considered as multi drug resistance (MDR) among which resistance to all 10 tested antibiotics was also observed. 29 isolates were also positive in terms of class 1 integron genes.

Treatment with the following antibiotics; Meropenem, Levofloxacin, Imipenem, and Gemtamicin, may be successful, since more than 80% of the isolates were susceptible to them. However, presence of MDR as well as detecting class 1 integron genes may be an alarming for infections caused by K. pneumoniae.

Knowing about the increase in the antibiotic resistance among K. pneumoniae isolates, the presence of MDR isolates, and also detecting the presence of genes involved in dissemination of resistant isolates may help to choose the more effective therapies.

Background &

Staphylococcus epidermidis is a member of the microbiota of human skin, respiratory system and gastrointestinal tract which its the most important virulence factor is the ability to form biofilms. The aim of this study was to investigate antibacterial resistance and investigation of biofilm production in clinical isolates of S. epidermidis in Guilan.Materials &

S. epidermidis were isolated from clinical specimens in Rasht. Antibiotic resistance of isolates was evaluated by disk diffusion method and phenotypic evaluation of         biofilm production capability by microplate method. The presence of genes involved in biofilm formation including icaA, icaD, bhp and aap was investigated by PCR.

Out of 70 isolated Staphylococcus epidermidis, the highest resistance was against        penicillin and vancomycin was the most effective antibiotic. In phenotypic assay, 38 isolates (54.3%) were able to produce biofilm, of which 94.7%, 55.3% and 42.1%, presence of icaA, icaD and aap genes were detected respectively. The bhp gene was not detected in the studied isolates.

The results indicate high rate of antibacterial resistance and biofilm forming ability in S. epidermidis isolates in Guilan and as a result the high potential of these isolates in              colonization, pathogenicity and acquisition of multidrug resistance.