ACI-1 class A beta-lactamase is widespread across human gut microbiomes due to transposons harboured by tailed prophages

AbstractAntibiotic resistance is increasing among pathogens at unprecedented rates and the human body contains a large pool of antibiotic resistance genes that can be spread among bacteria by mobile genetic elements. Acidaminococcus intestini, a bacterium found in the human gut that belongs to the class of Negativicutes, is the first gram-negative coccus shown to be resistant to beta-lactam antibiotics. Resistance is conferred by aci1, a gene encoding the ACI-1 class A beta-lactamase, but the evolutionary history of aci1 and its distribution across other Negativicutes and in the human gut microbiota remains obscure. We discovered that ACI-1 proteins are phylogenetically distinct from class A beta-lactamases of gram-positive Firmicutes and that the aci1 gene occurs in bacteria scattered across the Negativicutes clade, suggesting possible mobilization. In the reference A. intestini RyC-MR95 strain, we found that aci1 is surrounded by mobile DNA, transposon derived sequences directly flank aci1 and are likely the vehicle for its mobility. These transposon sequences reside within a prophage context consisting of two likely degraded tailed prophages, the first prophages to be characterised in A. intestini. We found aci1 in at least 56 (4.4%) out of 1,267 human gut metagenome samples, mostly hosted within A. intestini, and, where could be determined, mostly within a similar constellation of mobile elements to that found in the reference A. intestini genome. These human samples are from individuals in Europe, China and the USA, showing that aci1 is widely distributed globally. Additionally, we examined the nine different Negativicute genome assemblies that contain aci1, and found that only two of these strains show a similar mobile element context around aci1 to the reference A. intestini with transposons adjacent to a tailed prophage. However, in all nine cases aci1 is flanked by transposon derived sequences, and these sequences are diverse, suggesting the activity and degradation of multiple transposons. Overall, we show that ACI-1 proteins form a distinct class A beta lactamase family, and that the aci1 gene is present in human guts worldwide within Negativicute bacterial hosts, due to transposons, sometimes inserted into tailed prophages.

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Detection of ESBL and MBL Antibiotic Resistance Genes in 100 Clinical Isolates of Escherichia Coli by Multiplex PCR

10.21203/rs.3.rs-679205/v2 ◽

2021 ◽

Author(s):

bahman Ghadami Petroudi ◽

Rahman Shokri ◽

Davoud Esmaeili

Keyword(s):

Escherichia Coli ◽

Antibiotic Resistance ◽

Multiplex Pcr ◽

Bacterial Infections ◽

Antibiotic Resistance Genes ◽

Test Method ◽

Antibiotic Administration ◽

Beta Lactamase ◽

Beta Lactam ◽

Biochemical Tests

Abstract Bckground: Increasing use of beta-lactam antimicrobials in the treatment of bacterial infections has increased resistance against them. Objectives: This study aimed to investigate the patterns of antibiotic susceptibility to beta-lactam antibiotics and to investigate the presence of beta-lactamase and Metallo-beta-lactamase genes blaKPC, blaTEM, blaAmpc, blaIND, blaSIM, and blaGIM in clinical specimens of Escherichia coli.Methods: In this study, 100 urine samples were collected from different wards of hospitals and treatment centers in the west of Tehran province, and 100 strains of Escherichia coli were confirmed by biochemical tests. In the next step, a susceptibility test was performed on 3 selected antibiotics. Then, using the Combine Disk Test method, ESBL and MBL strains were identified. Finally, using the multiplex PCR method, the strains producing KPC, TEM, Ampc, IND, GIM, and SIM enzymes were identified.Results: In this study, the highest resistance of strains to cefotaxime was observed. n = 52 (52%) and their highest sensitivity to imipenem was seen n = 95 (95%). Also, n = 53 (53%) of the samples had ESBL genes. Also, 41 isolates (77%) of the studied strains contained the blaTEM gene, 12 isolates (23%) of the strains contained the blaAmpc gene and 20 isolates (38%) of the strains contained blakpc gene. Also, n= 19 (19%) of the samples had MBL genes. Also, 4 isolates (21%) of the strains contained the IND gene, 4 isolates (21%) of the strains contained the GIM gene, 7 isolates (37%) contained the SIM gene.Conclusion: Due to the high percentage of resistance to third-generation cephalosporins, careful antibiogram testing before antibiotic administration in infections caused by ESBL and MBL-producing organisms is an unavoidable necessity. Therefore, by quickly and correctly identifying the pattern of antibiotic resistance, the physician will be able to select the appropriate antibiotic therapy and prevent the spread of antibiotic resistance.

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Detection of ESBL and MBL Antibiotic Resistance Genes in 100 Clinical Isolates of Escherichia Coli by Multiplex PCR

10.21203/rs.3.rs-679205/v1 ◽

2021 ◽

Author(s):

Bahman Ghadami Petroudi ◽

Rahman Shokri ◽

Davoud Esmaeili

Keyword(s):

Escherichia Coli ◽

Antibiotic Resistance ◽

Multiplex Pcr ◽

Bacterial Infections ◽

Antibiotic Resistance Genes ◽

Test Method ◽

Antibiotic Administration ◽

Beta Lactamase ◽

Beta Lactam ◽

Biochemical Tests

Abstract Background: Increasing use of beta-lactam antimicrobials in the treatment of bacterial infections has increased resistance against them. Objectives: This study aimed to investigate the patterns of antibiotic susceptibility to beta-lactam antibiotics and to investigate the presence of beta-lactamase and Metallo-beta-lactamase genes blaKPC, blaTEM, blaAmpc, blaIND, blaSIM, and blaGIM in clinical specimens of Escherichia coli.Methods: In this study, 100 urine samples were collected from different wards of hospitals and treatment centers in the west of Tehran province, and 100 strains of Escherichia coli were confirmed by biochemical tests. In the next step, a susceptibility test was performed on 3 selected antibiotics. Then, using the Combine Disk Test method, ESBL and MBL strains were identified. Finally, using the multiplex PCR method, the strains producing KPC, TEM, Ampc, IND, GIM, and SIM enzymes were identified.Results: In this study, the highest resistance of strains to cefotaxime was observed. n = 52 (52%) and their highest sensitivity to imipenem was seen n = 95 (95%). Also, n = 53 (53%) of the samples had ESBL genes. Also, 41 isolates (77%) of the studied strains contained the blaTEM gene, 12 isolates (23%) of the strains contained the blaAmpc gene and 20 isolates (38%) of the strains contained blakpc gene. Also, n= 19 (19%) of the samples had MBL genes. Also, 4 isolates (21%) of the strains contained the IND gene, 4 isolates (21%) of the strains contained the GIM gene, 7 isolates (37%) contained the SIM gene.Conclusion: Due to the high percentage of resistance to third-generation cephalosporins, careful antibiogram testing before antibiotic administration in infections caused by ESBL and MBL-producing organisms is an unavoidable necessity. Therefore, by quickly and correctly identifying the pattern of antibiotic resistance, the physician will be able to select the appropriate antibiotic therapy and prevent the spread of antibiotic resistance.

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Oral Beta-Lactamase Protects the Canine Gut Microbiome from Oral Amoxicillin-Mediated Damage

Microorganisms ◽

10.3390/microorganisms7050150 ◽

2019 ◽

Vol 7 (5) ◽

pp. 150 ◽

Cited By ~ 4

Author(s):

Sheila Connelly ◽

Brian Fanelli ◽

Nur A. Hasan ◽

Rita R. Colwell ◽

Michael Kaleko

Keyword(s):

Antibiotic Resistance ◽

Small Intestine ◽

Resistance Genes ◽

Gut Microbiome ◽

Antibiotic Resistance Genes ◽

Oral Antibiotic ◽

Beta Lactamase ◽

Gi Tract ◽

Beta Lactam ◽

Beta Lactam Antibiotics

Antibiotics damage the gut microbiome, which can result in overgrowth of pathogenic microorganisms and emergence of antibiotic resistance. Inactivation of antibiotics in the small intestine represents a novel strategy to protect the colonic microbiota. SYN-004 (ribaxamase) is a beta-lactamase formulated for oral delivery intended to degrade intravenously administered beta-lactam antibiotics in the gastrointestinal (GI) tract. The enteric coating of ribaxamase protects the enzyme from stomach acid and mediates pH-dependent release in the upper small intestine, the site of antibiotic biliary excretion. Clinical benefit was established in animal and human studies in which ribaxamase was shown to degrade ceftriaxone in the GI tract, thereby preserving the gut microbiome, significantly reducing Clostridioides difficile disease, and attenuating antibiotic resistance. To expand ribaxamase utility to oral beta-lactams, delayed release formulations of ribaxamase, SYN-007, were engineered to allow enzyme release in the lower small intestine, distal to the site of oral antibiotic absorption. Based on in vitro dissolution profiles, three SYN-007 formulations were selected for evaluation in a canine model of antibiotic-mediated gut dysbiosis. Dogs received amoxicillin (40 mg/kg, PO, TID) +/- SYN-007 (10 mg, PO, TID) for five days. Serum amoxicillin levels were measured after the first and last antibiotic doses and gut microbiomes were evaluated using whole genome shotgun sequence metagenomics analyses of fecal DNA prior to and after antibiotic treatment. Serum amoxicillin levels did not significantly differ +/- SYN-007 after the first dose for all SYN-007 formulations, while only one SYN-007 formulation did not significantly reduce systemic antibiotic concentrations after the last dose. Gut microbiomes of animals receiving amoxicillin alone displayed significant loss of diversity and emergence of antibiotic resistance genes. In contrast, for animals receiving amoxicillin + SYN-007, microbiome diversities were not altered significantly and the presence of antibiotic resistance genes was reduced. These data demonstrate that SYN-007 diminishes amoxicillin-mediated microbiome disruption and mitigates emergence and propagation of antibiotic resistance genes without interfering with antibiotic systemic absorption. Thus, SYN-007 has the potential to protect the gut microbiome by inactivation of beta-lactam antibiotics when administered by both oral and parenteral routes and to reduce emergence of antibiotic-resistant pathogens.

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SYN-007, an Orally Administered Beta-Lactamase Enzyme, Protects the Gut Microbiome from Oral Amoxicillin/Clavulanate without Adversely Affecting Antibiotic Systemic Absorption in Dogs

Microorganisms ◽

10.3390/microorganisms8020152 ◽

2020 ◽

Vol 8 (2) ◽

pp. 152 ◽

Cited By ~ 2

Author(s):

Sheila Connelly ◽

Brian Fanelli ◽

Nur A. Hasan ◽

Rita R. Colwell ◽

Michael Kaleko

Keyword(s):

Antibiotic Resistance ◽

Gastrointestinal Tract ◽

Gut Microbiome ◽

Antibiotic Resistance Genes ◽

Systemic Absorption ◽

Beta Lactamase ◽

Beta Lactam ◽

Oral Amoxicillin ◽

Amoxicillin Clavulanate ◽

Lactamase Inhibitor

Beta-lactamases, enzymes produced by bacteria to degrade beta-lactam antibiotics, have been harnessed as therapeutics to protect the gut microbiome from damage caused by antibiotics. Proof-of-concept of this approach using SYN-004 (ribaxamase), a beta-lactamase formulated for oral delivery with intravenous (IV) penicillins and cephalosporins, was demonstrated with animal models and in humans. Ribaxamase degraded ceftriaxone in the gastrointestinal tract, protected the gut microbiome, significantly reduced the incidence of Clostridioides difficile disease and attenuated emergence of antibiotic resistant organisms. SYN-007 is a delayed release formulation of ribaxamase intended for use with oral beta-lactams. In dogs treated with oral amoxicillin, SYN-007 diminished antibiotic-mediated microbiome disruption and reduced the emergence of antibiotic resistance without altering amoxicillin systemic absorption. Here, SYN-007 function in the presence of clavulanate, a beta-lactamase inhibitor, was investigated. Dogs received amoxicillin (40 mg/kg, orally (PO), three times a day (TID)) or the combined antibiotic/beta-lactamase inhibitor, amoxicillin/clavulanate (40 mg/kg amoxicillin, 5.7 mg/kg clavulanate, PO, TID) +/™ SYN-007 (10 mg, PO, TID) for five days. Serum amoxicillin levels were not significantly different +/™ SYN-007 compared to amoxicillin alone or amoxicillin/clavulanate alone as controls for both first and last doses, indicating SYN-007 did not interfere with systemic absorption of the antibiotic. Whole genome shotgun metagenomics analyses of the fecal microbiomes demonstrated both amoxicillin and amoxicillin/clavulanate significantly reduced diversity and increased the frequency of antibiotic resistance genes. Microbiome damage appeared more severe with amoxicillin/clavulanate. In contrast, with SYN-007, microbiome diversity was not significantly altered, and frequency of antibiotic resistance genes did not increase. Importantly, SYN-007 functioned in the presence of clavulanate to protect the gut microbiome indicating that SYN-007 activity was not inhibited by clavulanate in the dog gastrointestinal tract. SYN-007 has the potential to expand microbiome protection to beta-lactam/beta-lactamase inhibitor combinations delivered orally or systemically.

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Impact of Hospital Wastewater on the Occurrence and Diversity of Beta-Lactamase Genes During Wastewater Treatment with an Emphasis on Carbapenemase Genes: A Metagenomic Approach

Frontiers in Environmental Science ◽

10.3389/fenvs.2021.738158 ◽

2021 ◽

Vol 9 ◽

Author(s):

Jakub Hubeny ◽

Sławomir Ciesielski ◽

Monika Harnisz ◽

Ewa Korzeniewska ◽

Tomasz Dulski ◽

...

Keyword(s):

Antibiotic Resistance ◽

Wastewater Treatment ◽

High Throughput Sequencing ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Antibiotic Resistance Genes ◽

Taxonomic Diversity ◽

Beta Lactamase ◽

Hospital Wastewater ◽

Beta Lactam

The diversity of beta-lactam antibiotic resistance genes, with particular emphasis on carbapenemase genes, during the treatment process at two wastewater treatment plants (WWTPs) with different levels of hospital wastewater inflow was investigated using high-throughput sequencing. An additional aspect of the study was to determine the taxonomic diversity of microorganisms in the studied samples. The obtained results suggest that bacteria of the Fusobacteriaceae family, not associated to date with this phenomenon, may be involved in the spread of antibiotic resistance in the environment. In samples from both wastewater treatment plants, the dominant beta-lactamase genes included blaOXA, blaGES, blaBEL, blaCfxA, and blaTEM. It is worth noting that the blaKPC and blaNDM genes were only found in untreated municipal wastewater with a higher hospital wastewater content. Moreover, an increase in the abundance of the blaIMP gene after the biological treatment stage in the studied treatment plants was found. In wastewater characterized by a higher proportion of hospital wastewater, 94 correlations were observed, while in wastewater with its lower proportion, 41 correlations were noted. Considering the above, the current research indicates that the inflow of hospital wastewater contributes to the spread of antibiotic resistance in the aquatic environment.

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HMD-ARG: hierarchical multi-task deep learning for annotating antibiotic resistance genes

Microbiome ◽

10.1186/s40168-021-01002-3 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Yu Li ◽

Zeling Xu ◽

Wenkai Han ◽

Huiluo Cao ◽

Ramzan Umarov ◽

...

Keyword(s):

Antibiotic Resistance ◽

Deep Learning ◽

Resistance Genes ◽

Antibiotic Resistance Genes ◽

Third Party ◽

Superior Performance ◽

Beta Lactamase ◽

Learning Framework ◽

Sequence Encoding ◽

Global Threat

Abstract Background The spread of antibiotic resistance has become one of the most urgent threats to global health, which is estimated to cause 700,000 deaths each year globally. Its surrogates, antibiotic resistance genes (ARGs), are highly transmittable between food, water, animal, and human to mitigate the efficacy of antibiotics. Accurately identifying ARGs is thus an indispensable step to understanding the ecology, and transmission of ARGs between environmental and human-associated reservoirs. Unfortunately, the previous computational methods for identifying ARGs are mostly based on sequence alignment, which cannot identify novel ARGs, and their applications are limited by currently incomplete knowledge about ARGs. Results Here, we propose an end-to-end Hierarchical Multi-task Deep learning framework for ARG annotation (HMD-ARG). Taking raw sequence encoding as input, HMD-ARG can identify, without querying against existing sequence databases, multiple ARG properties simultaneously, including if the input protein sequence is an ARG, and if so, what antibiotic family it is resistant to, what resistant mechanism the ARG takes, and if the ARG is an intrinsic one or acquired one. In addition, if the predicted antibiotic family is beta-lactamase, HMD-ARG further predicts the subclass of beta-lactamase that the ARG is resistant to. Comprehensive experiments, including cross-fold validation, third-party dataset validation in human gut microbiota, wet-experimental functional validation, and structural investigation of predicted conserved sites, demonstrate not only the superior performance of our method over the state-of-art methods, but also the effectiveness and robustness of the proposed method. Conclusions We propose a hierarchical multi-task method, HMD-ARG, which is based on deep learning and can provide detailed annotations of ARGs from three important aspects: resistant antibiotic class, resistant mechanism, and gene mobility. We believe that HMD-ARG can serve as a powerful tool to identify antibiotic resistance genes and, therefore mitigate their global threat. Our method and the constructed database are available at http://www.cbrc.kaust.edu.sa/HMDARG/.

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Novel Soil-Derived Beta-Lactam, Chloramphenicol, Fosfomycin and Trimethoprim Resistance Genes Revealed by Functional Metagenomics

Antibiotics ◽

10.3390/antibiotics10040378 ◽

2021 ◽

Vol 10 (4) ◽

pp. 378

Author(s):

Inka Marie Willms ◽

Maja Grote ◽

Melissa Kocatürk ◽

Lukas Singhoff ◽

Alina Andrea Kraft ◽

...

Keyword(s):

Antibiotic Resistance ◽

Resistance Genes ◽

Antibiotic Resistance Genes ◽

Reference Database ◽

Functional Metagenomics ◽

Beta Lactam ◽

Public Attention ◽

Soil Ecosystems ◽

High Level ◽

Antibiotic Efflux

Antibiotic resistance genes (ARGs) in soil are considered to represent one of the largest environmental resistomes on our planet. As these genes can potentially be disseminated among microorganisms via horizontal gene transfer (HGT) and in some cases are acquired by clinical pathogens, knowledge about their diversity, mobility and encoded resistance spectra gained increasing public attention. This knowledge offers opportunities with respect to improved risk prediction and development of strategies to tackle antibiotic resistance, and might help to direct the design of novel antibiotics, before further resistances reach hospital settings or the animal sector. Here, metagenomic libraries, which comprise genes of cultivated microorganisms, but, importantly, also those carried by the uncultured microbial majority, were screened for novel ARGs from forest and grassland soils. We detected three new beta-lactam, a so far unknown chloramphenicol, a novel fosfomycin, as well as three previously undiscovered trimethoprim resistance genes. These ARGs were derived from phylogenetically diverse soil bacteria and predicted to encode antibiotic inactivation, antibiotic efflux, or alternative variants of target enzymes. Moreover, deduced gene products show a minimum identity of ~21% to reference database entries and confer high-level resistance. This highlights the vast potential of functional metagenomics for the discovery of novel ARGs from soil ecosystems.

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Growing Menace of Antibacterial Resistance in Clinical Isolates ofPseudomonas aeruginosain Nepal: An Insight of Beta-Lactamase Production

BioMed Research International ◽

10.1155/2016/6437208 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Shamshul Ansari ◽

Rabindra Dhital ◽

Sony Shrestha ◽

Sangita Thapa ◽

Ram Puri ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Antibiotic Resistance ◽

Opportunistic Pathogen ◽

Resistance Rate ◽

Diffusion Method ◽

Beta Lactamase ◽

Beta Lactam ◽

Beta Lactam Antibiotics ◽

Microbiological Methods ◽

Immunosuppressed Patients

Introduction. Pseudomonas aeruginosais the most frequently isolated organism as it acts as the opportunistic pathogen and can cause infections in immunosuppressed patients. The production of different types of beta-lactamases renders this organism resistant to many commonly used antimicrobials. Therefore, the aim of this study was to document the antibiotic resistance rate inPseudomonas aeruginosaisolated from different clinical specimens.Methods. Pseudomonas aeruginosarecovered was identified by standard microbiological methods. Antibiotic susceptibility testing was performed by modified Kirby-Bauer disc diffusion method following Clinical and Laboratory Standard Institute (CLSI) guidelines and all the suspected isolates were tested for the production of ESBLs, MBLs, and AmpC.Results.Out of total (178) isolates, 83.1% were recovered from the inpatient department (IPD). Majority of the isolates mediated resistance towards the beta-lactam antibiotics, while nearly half of the isolates were resistant to ciprofloxacin. Most of the aminoglycosides used showed resistance rate up to 75% but amikacin proved to be better option. No resistance to polymyxin was observed. ESBLs, MBLs, and AmpC mediated resistance was seen in 33.1%, 30.9%, and 15.7% isolates, respectively.Conclusions. Antibiotic resistance rate and beta-lactamase mediated resistance were high. Thus, regular surveillance of drug resistance is of utmost importance.

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Monitoring and Evaluation of Antibiotic Resistance Genes in Three Rivers in Northeast China

10.21203/rs.3.rs-313046/v2 ◽

2021 ◽

Author(s):

Chen Zhao ◽

Chenyu Li ◽

Xiaoming Wang ◽

Zhuosong Cao ◽

Chao Gao ◽

...

Keyword(s):

Antibiotic Resistance ◽

River Water ◽

Resistance Genes ◽

Northeast China ◽

Pathogenic Bacteria ◽

Respiratory Infections ◽

Antibiotic Resistance Genes ◽

Distribution Characteristics ◽

Beta Lactam ◽

Three Rivers

Abstract Background: Antibiotic resistance genes (ARGs) have become an important public health problem. In this study, we used metagenomic sequencing to analyze the composition of ARGs in certain original habitats of northeast China, comprising three different rivers and riverbank soils of the Heilongjiang River, Tumen River, and Yalu River. Results: Twenty types of ARG were detected in every water sample. The major ARGs were multidrug resistance genes, at approximately 0.5 copies/16s rRNA, accounting for 57.5% of the total ARG abundance. The abundance of multidrug, bacitracin, beta-lactam, macrolide‑lincosamide‑streptogramin, sulfonamide, fosmidomycin, and polymyxin resistance genes covered 96.9% of the total ARG abundance. No significant ecological boundary of ARG diversity was observed. The compositions of the resistance genes in the three rivers were very similar to each other, and 92.1% of ARG subtypes were shared by all water samples. Except for vancomycin resistance genes, almost all ARGs in riverbank soils were detected in the river water. About 31.05% ARGs were carried by Pseudomonas. Opportunistic pathogenic bacteria carrying resistance genes were mainly related to diarrhea and respiratory infections. Multidrug and beta-lactam resistance genes correlated positively with mobile genetic elements (MGEs), indicating a potential risk of diffusion.Conclusions: The composition of ARGs in three different rivers was similar, indicating that climate played an important role in ARG occurrence. ARG subtypes in river water were almost completely the same as those in riverbank soil. ARGs had no significant geographical distribution characteristics. Many ARGs were carried by human pathogenic bacteria related to human diarrhea and respiratory infections, such as Pseudomonas aeruginosa and Aeromonas caviae. In general, our results provide a valuable dataset of river water ARG distribution in northeast China. The related ecological geography distribution characteristics should be further explored.

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The Staphylococcal Cassette Chromosome mec (SCCmec) Analysis and Biofilm Formation of Methicillin-Resistant Staphylococcus cohnii Isolated from Clinical Samples in Tehran, Iran

Recent Patents on Anti-Infective Drug Discovery ◽

10.2174/1574891x16666210210101912 ◽

2021 ◽

Vol 16 ◽

Author(s):

Somaye Delfani ◽

Faranak Rezaei ◽

Setareh Soroush ◽

Pegah Shakib

Keyword(s):

Antibiotic Resistance ◽

Biofilm Formation ◽

Antibiotic Resistance Genes ◽

Mobile Element ◽

Diffusion Method ◽

Clinical Samples ◽

Coagulase Negative Staphylococci ◽

Methicillin Resistant ◽

Inducible Clindamycin Resistance ◽

Sccmec Types

Background: Methicillin-resistant coagulase-negative staphylococci is responsible for hospital and community-acquired infections. Objective: This study aimed to investigate the antibiotic-resistance patterns, antibiotic-resistance genes, namely, ermA, ermB, ermC, blaZ, msrA, tetK, tetM, mup, and vanA, biofilm formation, and prevalence of different SCCmec types among the Staphylococcus cohniistrains isolated from clinical samples in Tehran, Iran. Methods: In this study,S. cohniiisolates were screened from the clinical samples from March 2012 to February 2013 in Tehran, Iran.Antimicrobial susceptibility test and inducible clindamycin resistance were evaluated by disc diffusion method, andresistance genes were examined using Polymerase Chain Reaction (PCR) assays. Then, biofilm formation assay was analyzed by Microtiter-plate test to detect the icaA and icaDgenes. The SCCmec and the Arginine Catabolite Mobile Element (ACME) typing were performed using the PCRmethod. Results: FromtwentyS. cohnii, all isolates were resistant to cefoxitin. 95% of the S. cohnii was defined as multidrug resistance (MDR)strains. The ermB, ermC, and vanA genes were not detected in any isolates; however, the blaZ gene had the highest frequency.95% of the S. cohnii isolates produced biofilm. Also, 4 SCCmec types, including V, IV, III+ (C2), VIII+ (AB1), were identified. Therefore, the majority of SCCmec were untypable. Based on the ACME typing, arcA and opp3 genes were positive in 13 (65%) and 1 (5%) isolates, respectively. Conclusion: Due to the high antimicrobial resistance and the spread of untypableSCCmecamong the isolates studied, the control and treatment of methicillin-resistantS. cohnii in hospitals and public health centers is a significant concern.

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