Prevalence of inducible clindamycin resistance in methicillin-resistant Staphylococcus aureus: the first study in Jordan. - Related Documents




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237501.0000Prevalence of inducible clindamycin resistance in methicillin-resistant Staphylococcus aureus: the first study in Jordan. INTRODUCTION: A high rate of infections with methicillin-resistant Staphylococcus aureus (MRSA) has been documented, in both hospital- (HA-MRSA) and community-acquired (CA-MRSA) diseases in Jordan. Erythromycin and clindamycin are considered treatments of choice. However, resistance to erythromycin with false susceptibility to clindamycin in vitro may lead to therapeutic failure. Hence, it is mandatory to study the prevalence of inducible resistance to macrolide-lincosamide-streptogramin B (iMLSB) antibiotics conferred by erm genes in those bacteria. METHODOLOGY: S. aureus isolates were identified morphologically and biochemically, and MRSA were appraised using standard procedures. Induction in resistance to MLSB antibiotics among MRSA isolates was detected phenotypically using the D-test, and the presence of erm genes was revealed by polymerase chain reaction (PCR). RESULTS: Of 126 collected Staphylococcus isolates, 71 (56.3%) isolates were S. aureus, of which 55 (77.5%) were MRSA. A total of 43 (78.2%) MRSA-discordant isolates were resistant to erythromycin, of which 33 (76.7%) exhibited the iMLSB (D-test positive), 2 (4.7%) the MSB (D-test negative), and 8 (18.6%) the constitutive resistant (cMLSB) phenotypes. Induction of clindamycin resistance was 1.6 times greater in CA-MRSA than in HA-MRSA. Furthermore, ermA and ermC were significantly prevalent in HA-MRSA and CA-MRSA, respectively. CONCLUSIONS: Continuous surveillance of the MLSB resistance is important and required before the prescription of clindamycin to treat MRSA infections.201728459227
235410.9998Resistance profiles of Staphylococcus aureus isolates against frequently used antibiotics at private sector laboratories in Jordan. BACKGROUND AND OBJECTIVES: Staphylococcus aureus (S. aureus) is one of the most important pathogens, responsible for a range of infections. This study aimed to assess resistance patterns in S. aureus isolates obtained from certain private-sector laboratories against commonly used antimicrobial agents. MATERIALS AND METHODS: The process involved collecting various samples from several private laboratories and then identifying S. aureus isolates using biochemical characterization. The antibiotic susceptibility of these isolates was determined by disc diffusion method. Furthermore, Rt-PCR was employed to identify two genes namely the methicillin/oxacillin resistance genes (mecA), and (SCCmec). RESULTS: The findings of the current study exhibited that females constituted a larger proportion of the participants (59.1%) compared to males (40.9%), with a mean participant age of 40.82 years. Gram-positive bacteria were more prevalent (71.3%) than Gram-negative bacteria (18.3%), with S. aureus being the most frequent isolate (60.9%). Urine samples represented the highest collected sample type (47.8%). Out of the 115 bacterial isolates, 85.2% exhibited multidrug resistance to antibiotics such as cefazolin, gentamicin, vancomycin, and ceftazidime. Clindamycin was the most effective antibiotic, with a sensitivity rate of 62.9%, followed by teicoplanin and meropenem, each with a sensitivity rate of 52.9%. Methicillin-resistant Staphylococcus aureus (MRSA) strains were susceptabile to vancomycin and teicoplanin. The methicillin/oxacillin resistant isolates showed significant association with mecA and SCCA genes. CONCLUSION: This study highlighted the multi-drug resistance in S. aureus isolates, stressing the need for stringent antibiotic stewardship, continuous surveillance, and further research into alternative treatments, including novel antibiotics and combination therapy, to combat resistant strains.202540337673
235220.9998Phenotypic and Molecular Detection of Biofilm Formation in Methicillin-Resistant Staphylococcus Aureus Isolated from Different Clinical Sources in Erbil City. BACKGROUND: Staphylococcus aureus is an important causative pathogen. The production of biofilms is an important factor and makes these bacteria resistant to antimicrobial therapy. OBJECTIVES: the current study aimed to assess the prevalence of resistance to antibacterial agents and to evaluate the phenotypic and genotypic characterization of biofilm formation among S. aureus strains. METHODS: This study included 50 isolates of Methicillin-resistant S. aureus (MRSA) and Methicillin-Susceptible S. aureus (MSSA). S. aureus was identified by molecular and conventional methods, and antimicrobial resistance was tested with a disc diffusion method. The biofilm formation was performed through the Microtiter plate method. Strains were subjected to PCR to determine the presence of nuc, mecA, icaA, icaB, icaC, and icaD genes. RESULTS: Of the 50 S. aureus isolates, 32(64%) and 18(36%) were MRSA and MSSA, respectively. A large number of MRSA and MSSA isolates showed resistance to Penicillin and Azithromycin, and a lower number of MRSA and MSSA isolates showed resistance to Amikacin Gentamicin. None of the isolates was resistant to Vancomycin. The MRSA strains had significantly higher resistance against antibiotics than MSSA strains (P = 0.0154). All isolates (MRSA and MSSA) were able to produce biofilm with levels ranging from strong (31.25 %), (16.6%) to moderate (53.12%), (50%) to weak (15.6%), (33.3%) respectively. The MRSA strains had a significantly higher biofilm formation ability than the MSSA strains (P = 0.0079). The biofilm-encoding genes were detected among isolates with different frequencies. The majority of S. aureus isolates, 42 (84%), were positive for the icaA. The prevalence rates of the icaB, icaC and icaD genes were found to be 37 (74%), 40 (80%) and 41 (82%), respectively. CONCLUSIONS: The prevalence of biofilm encoding genes associated with multidrug resistance in S. aureus strains is high. Therefore, identifying epidemiology, molecular characteristics, and biofilm management of S. aureus infection would be helpful.202336908866
235930.9998Virulence Factor Genes and Antimicrobial Susceptibility of Staphylococcus aureus Strains Isolated from Blood and Chronic Wounds. Staphylococcus aureus is one of the predominant bacteria isolated from skin and soft tissue infections and a common cause of bloodstream infections. The aim of this study was to compare the rate of resistance to various antimicrobial agents and virulence patterns in a total of 200 S. aureus strains isolated from patients with bacteremia and chronic wounds. Disk diffusion assay and in the case of vancomycin and teicoplanin-microdilution assay, were performed to study the antimicrobial susceptibility of the isolates. The prevalence of genes encoding six enterotoxins, two exfoliative toxins, the Panton-Valentine leukocidin and the toxic shock syndrome toxin was determined by PCR. Of the 100 blood strains tested, the highest percentage (85.0%, 31.0%, and 29.0%) were resistant to benzylpenicillin, erythromycin and clindamycin, respectively. Out of the 100 chronic wound strains, the highest percentage (86.0%, 32.0%, 31.0%, 31.0%, 30.0%, and 29.0%) were confirmed as resistant to benzylpenicillin, tobramycin, amikacin, norfloxacin, erythromycin, and clindamycin, respectively. A significantly higher prevalence of resistance to amikacin, gentamicin, and tobramycin was noted in strains obtained from chronic wounds. Moreover, a significant difference in the distribution of sea and sei genes was found. These genes were detected in 6.0%, 46.0% of blood strains and in 19.0%, and 61.0% of wound strains, respectively. Our results suggest that S. aureus strains obtained from chronic wounds seem to be more often resistant to antibiotics and harbor more virulence genes compared to strains isolated from blood.202134357963
132840.9998Analysis of Resistance to Macrolide-Lincosamide-Streptogramin B Among mecA-Positive Staphylococcus Aureus Isolates. OBJECTIVES: Genetic determinants conferring resistance to macrolide, lincosamide, and streptogramin B (MLS(B)) via ribosomal modification such as, erm, msrA/B and ereA/B genes are distributed in bacteria. The main goals of this work were to evaluate the dissemination of MLS(B) resistance phenotypes and genotypes in methicillin-resistant Staphylococcus aureus (MRSA) isolates collected from clinical samples. METHODS: A total of 106 MRSA isolates were studied. Isolates were recovered from 3 hospitals in Tehran between May 2016 to July 2017. The prevalence of MLS(B)-resistant strains were determined by D-test, and then M-PCR was performed to identify genes encoding resistance to macrolides, lincosamides, and streptogramins in the tested isolates. RESULTS: The frequency of constitutive resistance MLS(B), inducible resistance MLS(B) and MS(B) resistance were 56.2%, 22.9%, and 16.6%, respectively. Of 11 isolates with the inducible resistance MLS(B) phenotype, ermC, ermB, ermA and ereA were positive in 81.8%, 63.6%, 54.5% and 18.2% of these isolates, respectively. In isolates with the constitutive resistance MLS(B) phenotype, the prevalence of ermA, ermB, ermC, msrA, msrB, ereA and ereB were 25.9%, 18.5%, 44.4%, 0.0%, 0.0%, 11.1% and 0.0%, respectively. CONCLUSION: Clindamycin is commonly administered in severe MRSA infections depending upon the antimicrobial susceptibility findings. This study showed that the D-test should be used as an obligatory method in routine disk diffusion assay to detect inducible clindamycin resistance in MRSA so that effective antibiotic treatment can be provided.201930847268
237750.9998Multidrug-resistant and enterotoxigenic methicillin-resistant Staphylococcus aureus isolated from raw milk of cows at small-scale production units. OBJECTIVE: Staphylococcus aureus (S. aureus) has evolved as one of the most significant bacteria causing food poisoning outbreaks worldwide. This study was carried out to investigate the prevalence, antibiotic sensitivity, virulence, and enterotoxin production of S. aureus in raw milk of cow from small-scale production units and house-raised animals in Damietta governorate, Egypt. MATERIAL AND METHODS: The samples were examined bacteriologically, and antimicrobial sensitivity testing was carried out. Moreover, isolates were characterized by the molecular detection of antimicrobial resistance, virulence, and enterotoxin genes. RESULTS: Out of 300 milk samples examined, S. aureus was isolated from 50 samples (16.7%). Antibiotic sensitivity testing revealed that isolates were resistant to β-lactams (32%), tetracycline (16%), and norfloxacin (16%); however, they showed considerable sensitivity to ceftaroline and amikacin (72%). Multidrug-resistance (MDR) has been observed in eight isolates (16%), with a MDR index (0.5) in all of them. Of the total S. aureus isolates obtained, methicillin-resistant S. aureus (MRSA) has been confirmed molecularly in 16/50 (32%) and was found to carry mecA and coa genes, while virulence genes; hlg (11/16, 68.75%) and tsst (6/16, 37.5%) were amplified at a lower percentage, and they showed a significant moderate negative correlation (r = -0.59, p-value > 0.05). Antibiotic resistance genes have been detected in resistant isolates relevant to their phenotypic resistance: blaZ (100%), tetK (50%), and norA (50%). Fifty percent of MRSA isolates carried the seb enterotoxin gene. CONCLUSION: High detection rate of MRSA and MDR isolates from milk necessitates the prompt implementation of efficient antimicrobial stewardship guidelines, especially at neglected small-scale production units.202235445112
235860.9998Genotypic and Phenotypic Evaluation of Biofilm Production and Antimicrobial Resistance in Staphylococcus aureus Isolated from Milk, North West Province, South Africa. Background: Biofilm formation in S. aureus may reduce the rate of penetration of antibiotics, thereby complicating treatment of infections caused by these bacteria. The aim of this study was to correlate biofilm-forming potentials, antimicrobial resistance, and genes in S. aureus isolates. Methods: A total of 64 milk samples were analysed, and 77 S. aureus were isolated. Results: Seventy (90.9%) isolates were biofilm producers. The ica biofilm-forming genes were detected among 75.3% of the isolates, with icaA being the most prevalent (49, 63.6%). The icaB gene was significantly (P = 0.027) higher in isolates with strong biofilm formation potentials. High resistance (60%-90%) of the isolates was observed against ceftriaxone, vancomycin, and penicillin, and 25 (32.5%) of S. aureus showed multidrug resistance (MDR) to at least three antibiotics. Five resistance genes, namely blaZ (29, 37.7%), vanC (29, 37.7%), tetK (24, 31.2%), tetL (21, 27.3%), and msrA/B (16, 20.8%) were detected. Most MDR phenotypes possessed at least one resistance gene alongside the biofilm genes. However, no distinct pattern was identified among the resistance and biofilm phenotypes. Conclusions: The high frequency of potentially pathogenic MDR S. aureus in milk samples intended for human consumption, demonstrates the public health relevance of this pathogen in the region.202032252278
235370.9997Contribution of icaADBC genes in biofilm production ability of Staphylococcus aureus clinical isolates collected from hospitalized patients at a burn center in North of Iran. INTRODUCTION: The pathogenicity of Staphylococcus aureus is significantly attributed to its capacity to produce biofilms, which bolster bacterial resistance against antibiotics and host immune responses. This study aimed to explore the involvement of icaABCD genes in biofilm formation ability of S. aureus clinical isolates. MATERIALS AND METHODS: One hundred clinical S. aureus isolates were collected from hospitalized patients at a burn center in North of Iran. The isolates were identified using standard biochemical tests and confirmed by the presence of the nuc gene. Antibiotic susceptibility profiles were determined through the disk agar diffusion method. Biofilm formation capacity was determined using microtiter plate assay. PCR test was conducted to detect the presence of icaABCD genes. RESULTS: Penicillin exhibited the highest resistance rate (94%), while vancomycin was most effective antibiotic with 6% resistance. Besides, 32% of the isolates demonstrated as multidrug resistant (MDR) and 29% were Methicillin-resistant S. aureus (MRSA). Notably, 89% of the isolates were identified as biofilm produces, while 54 (60.67%), 28 (31.46%), and 7 (7.86%) isolates exhibited strong, moderate, and weakly biofilm production ability, respectively. PCR results revealed a prevalence of 90%, 92%, 92%, and 94% for the icaA, icaB, icaC, and icaD genes, respectively. Intriguingly, the MDR isolates exhibited a 100% prevalence of these genes. Similarly, 96.55%, 89.65%, 89.65% and 96.55% of the MRSA isolates were carrying the icaA, icaB, icaC, and icaD genes, respectively. CONCLUSION: This study revealed a noteworthy prevalence of biofilm-producing strains of S. aureus. High prevalence of icaADBC genes as well as highlighted capacity of the biofilm formation in MRSA and MDR strains exhibited a potential correlation between biofilm and antibiotic resistance patterns. Given the enhanced resilience of bacteria within biofilms against antibiotics, addressing biofilm production is imperative alongside antibiotic treatments for effective control and eradication of infections.202540382552
237680.9997Molecular characterization and antimicrobial susceptibility of methicillin-resistant staphylococcus aureus isolates from clinical samples and asymptomatic nasal carriers in Istanbul (Turkey). BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) has been a widespread problem in Turkish hospitals. AIMS: The aim of this study was to investigate the staphylococcal toxin genes of the clinical and nasal MRSA isolates, and their antibiotic resistance profiles. MATERIALS AND METHODS: Isolation of nasal and clinical bacteria was done following standard microbiological methods. The presence of antimicrobial resistance genes (mec A, pvl, tsst-1, and SEs genes) was determined using the real-time polymerase chain reaction (PCR) assay. RESULTS: Among nasal MRSA isolates, 66.7% were toxigenic. The distribution of genes was as follows: pvl 26.7%, tsst-1 3.3%, and SEs 36.7%. Therefore, the nasal MRSA isolates had a rate of 23.3% multidrug resistance (MDR) pattern to the non-beta-lactams antibiotics. All (100%) clinical MRSA isolates were found to be toxigenic. The distribution of genes was as follows; pvl 10%, tsst-1 6.7%, and SEs 100%. The clinical MRSA isolates had a rate of 60% MDR. CONCLUSIONS: Following detection of pvl, tsst-1, and SEs among nasal and clinical MRSA isolates, and the presence of high antimicrobial resistance, the spread of these strains may be an additional factor contributing to the emergence of community-acquired (CA)-MRSA and hospital-acquired (HA)-MRSA. This study is the first to determine the resistance to linezolid and tigecycline in both nasal and clinical MRSA isolates, for the first time in Turkey. All nasal and clinical MRSA isolates were uniformly susceptible to vancomycin and quinupristin-dalfopristin. Our findings show that MRSA infections in Turkey can be empirically treated with vancomycin and quinupristin-dalfopristin based on the lack of demonstrable resistance to these drugs.202134290175
236390.9997Analysis of distribution and antibiotic resistance of Gram-positive bacteria isolated from a tertiary-care hospital in southern China: an 8-year retrospective study. OBJECTIVE: Due to the severe drug resistance situation of Gram-negative bacteria, especially Gram-negative enterobacter, relatively little attention has been paid to the changes in Gram-positive bacteria species and drug resistance. Therefore, this study analyzed the prevalence and drug resistance of Gram-positive bacteria in a general tertiary-care hospital from 2014 to 2021, in order to discover the changes in Gram-positive bacteria distribution and drug resistance that cannot be easily identified, inform clinicians in their respective regions when selecting antimicrobial agents, and to provide the basis for the diagnosis of Gram-positive bacterial infection, and for the comprehensive and multi-pronged prevention and control of drug-resistant bacteria. METHODS: A retrospective study was conducted on Gram-positive bacteria isolated from patients presented to a general tertiary-care hospital from January 2014 to December 2021. A total of 15,217 Gram-positive strains were analyzed. RESULTS: During the 8-year period, the total number and the species of Gram-positive bacteria isolated from clinic increased continuously. The seven most common species were Streptococcus pneumoniae (21.2%), Staphylococcus aureus (15.9%), Enterococcus faecium (20.6%), Enterococcus faecalis (14.0%), and Staphylococcus epidermidis (7.8%), Staphylococcus haemolyticus (4.8%), Streptococcus agalactiae (3.6%). The isolation rates of Staphylococcus aureus and Streptococcus agalactiae increased, and the isolation rate of Enterococcus faecium decreased. The resistance rates of Staphylococcus aureus to erythromycin, clindamycin, tetracycline, rifampicin and furantoin decreased obviously. The resistance rates of Streptococcus pneumoniae to cefepime (non-meningitis) and ceftriaxone (meningitis) decreased significantly. The resistance rates of Enterococcus faecium to penicillin, ampicillin, erythromycin, levofloxacin, ciprofloxacin and furantoin rose rapidly from 50.3, 47.6, 71.5, 44.9, 52.3, and 37.5% in 2014 to 93.1, 91.6, 84.9, 86.8, 86.8, and 60.0% in 2021, respectively. CONCLUSION: The total number and the species of Gram-positive bacteria isolated during the 8-year period increased continuously. Streptococcus pneumoniae and Staphylococcus aureus are the main causes of positive bacterial infections in this hospital. The resistance rates of Enterococcus faecium to a variety of commonly used antibiotics increased significantly. Therefore, it is very important to monitor the distribution of bacteria and their resistance to antibiotics to timely evaluate and identify changes in drug resistance that are not easily detected.202337840716
2357100.9997Prevalence of Methicillin and β-Lactamase Resistant Pathogens Associated with Oral and Periodontal Disease of Children in Mymensingh, Bangladesh. Oral and periodontal diseases (OPD) is considered one of the main problems of dentistry worldwide. This study aimed to estimate the prevalence of oral and periodontal pathogenic bacteria along with their antimicrobial resistance pattern in 131 children patients aged between 4-10 years who attended in Mymensingh Medical College Hospital during October 2019 to March 2020. OPD pathogens were identified through isolation, cultural and biochemical properties, and nucleic acid detection. The isolates were subjected to antimicrobial susceptibility to 12 antibiotics commonly used in dentistry. In addition, the isolates were analyzed molecularly for the presence of six virulence and three antibacterial resistance genes. Five pathogens were identified, of which Staphylococcus aureus (S. aureus) (49%) and S. salivarius (46%) were noticed frequently; other bacteria included S. mutans (16.8%), S. sobrinus (0.8%) and L. fermentum (13.7%). The virulence genes-clumping factor A (clfA) was detected in 62.5% isolates of S. aureus, and gelatinase enzyme E (gelE) gene was detected in 5% isolates of S. salivarius, while other virulence genes were not detected. All the tested isolates were multidrug-resistant. The overall prevalence of MDR S. aureus, Streptococcus spp. and L. fermentum was 92.2%, 95.1% and 100%, respectively. It was observed that a high proportion of isolates were found resistant to 5-8 antibiotics. A majority of S. aureus, Streptococcus spp., and L. fermentum isolates tested positive for the β-lactamase resistance genes blaTEM and cfxA, as well as the methicillin resistance gene mecA. Phylogenetically, the resistance genes showed variable genetic character among Bangladeshi bacterial pathogens. In conclusion, S. aureus and S. salivarius were major OPD pathogens in patients attended in Mymensingh Medical College Hospital of Bangladesh, and most were Beta-lactam and methicillin resistant.202236015011
2287110.9997Expression of norA, norB and norC efflux pump genes mediating fluoroquinolones resistance in MRSA isolates. INTRODUCTION: Although fluoroquinolones are used to treat methicillin-resistant Staphylococcus aureus (MRSA)-induced infections, acquisition of antibiotic resistance by bacteria has impaired their clinical relevance. We aimed to evaluate the frequency of norA, norB, and norC efflux pump genes-mediating fluoroquinolones resistance and measure their expression levels in MRSA isolates. METHODOLOGY: 126 S. aureus isolates were collected from different clinical samples of adult hospitalized patients and identified by conventional microbiological methods. MRSA was diagnosed by cefoxitin disc diffusion method and minimum inhibitory concentration (MIC) of ciprofloxacin by broth microdilution method. The expression levels of efflux pump genes were measured by quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: 80 (63.5%) MRSA isolates were identified and showed high level of resistance to erythromycin (80%), gentamicin (75%), clindamycin (65%) and ciprofloxacin (60 %). norA, norB and norC were detected in 75%, 35% and 55% of the MRSA isolates respectively. norC was the most commonly overexpressed gene measured by qRT-PCR, occurring in 40% of MRSA isolates, followed by norA (35%) and norB (30%). The expression of these genes was significantly higher in ciprofloxacin-resistant than quantitative real-time PCR ciprofloxacin-sensitive MRSA isolates. CONCLUSIONS: This study showed high prevalence and overexpression of efflux pump genes among MRSA isolates which indicates the significant role of these genes in the development of multidrug resistance against antibiotics including fluoroquinolones.202438635612
2349120.9997DETECTION OF MECA AND NUC GENES OF MULTI-DRUG RESISTANT STAPHYLOCOCCUS AUREUS ISOLATED FROM DIFFERENT CLINICAL SAMPLES. BACKGROUND: During this study, six isolates of multiple antibiotic resistant Staphylococcus aureus bacteria were obtained from different clinical specimens (burn swabs, urinary tract infections, wound swabs): three isolates from burns, two isolates from urinary tract infections, and one isolate from wound swabs. They were obtained from private laboratories in Baghdad from 1/1/2023 to 3/15/2023. METHOD: The diagnosis of these isolates was confirmed using the Vitek2 device. A susceptibility test was conducted on ten antibiotics, and S. aureus bacteria showed resistance to most antibiotics, polymerase chain reaction was done to mecA and Nuc gene by conventional PCR. RESULTS: The results of the molecular detection of the MecA gene showed that all isolates of multi-drug-resistant S. aureus possess this gene. In contrast, the results of the molecular detection of the nuc gene showed that only isolates No. 1 and No. 4 carry this gene, while the rest of the isolates do not carry this gene. CONCLUSION: S. aureus are resistant to antibiotics because they possess resistance genes such as the mecA gene.202439724880
2658130.9997Rapid detection of major enterotoxin genes and antibiotic resistance of Staphylococcus aureus isolated from raw milk in the Yazd province, Iran. INTRODUCTION: Raw milk is a nutrient-rich food, but it may harbour harmful bacteria, such as enterotoxigenic Staphylococcus aureus (S. aureus), which can cause staphylococcal food poisoning. Antibiotic resistance of S. aureus in raw milk can increase the risk of such infections, particularly among susceptible individuals. OBJECTIVE: This study aimed to investigate the prevalence of enterotoxin genes a, d, g, i and j and the antibiotic resistance of S. aureus isolated from raw milk samples. METHODS: During a 6-month sampling period, 60 raw milk specimens were obtained from diverse locations in Yazd province, Iran. Antibiogram profiling was conducted via the disc diffusion method. In addition, staphylococcal enterotoxin (SE) genes a, d, g, i, and j were detected through real-time PCR analysis. RESULTS: Bacteriological assays confirmed the presence of S. aureus in 11 samples (18.3%). All isolates demonstrated 100% resistance to penicillin G but exhibited sensitivity to vancomycin, while resistance to other antibiotics ranged from 36.4% to 45.5%. The prevalence of enterotoxin genes in these strains showed variable distribution, with sea being the predominant SE (45.5%), followed by sed (36.4%), seg (18.2), sej and sei (9.1% each). CONCLUSIONS: This study discovered the presence of multiple enterotoxins in S. aureus strains obtained from raw milk samples. These strains also demonstrated resistance to a variety of antibiotics. Since enterotoxigenic S. aureus is known to cause human food poisoning, monitoring food hygiene practices, especially during raw milk production, is critical.202438519836
2661140.9997Antimicrobial resistance in Staphylococcus pseudintermedius on the environmental surfaces of a recently constructed veterinary hospital in Southern Thailand. BACKGROUND AND AIM: Staphylococcus pseudintermedius is a zoonotic bacterium commonly found in animals, especially dogs. These bacteria can survive on environmental surfaces for several months. The infection of S. pseudintermedius from the environment is possible, but properly cleaning surface objects can prevent it. This study aimed to investigate the prevalence of methicillin-resistant S. pseudintermedius (MRSP) in the environment of a recently constructed veterinary hospital in Southern Thailand, where we hypothesized that the prevalence of MRSP might be very low. MATERIALS AND METHODS: At three different time points, 150 samples were collected from different environmental surfaces and wastewater across the veterinary hospital. The collection was done after the hospital's cleaning. Bacteria were purified in the culture before being identified as species by biochemical tests and polymerase chain reaction (PCR). Next, the antimicrobial-resistant profile was performed using an automated system (Vitek 2). Finally, the antimicrobial resistance genes were identified using PCR. RESULTS: Fifteen colonies of S. pseudintermedius were isolated from the surfaces of eight floors, four tables, two chairs, and one rebreathing tube. Fourteen colonies (93.3%) were multidrug-resistant (MDR) and carried the blaZ gene (93.3%). The majority of colonies were resistant to benzylpenicillin (93.3%), cefovecin (93.3%), ceftiofur (93.3%), kanamycin (93.3%), and neomycin (93.3%). Notably, only four colonies (26.7%) were methicillin-susceptible S. pseudintermedius, whereas 11 colonies (73.3%) were MRSP and carried both the mecA and blaZ genes. Five MRSP (45.5%) were resistant to at least 14 antimicrobial drugs, represented as extensively drug-resistant (XDR) bacteria. Ten of eleven MRSP (90.9%) were Staphylococcal chromosomal mec type V, while another displayed untypeable. Despite the routine and extensive cleaning with detergent and disinfectant, MRSP isolates were still detectable. CONCLUSION: Many isolates of MRSP were found in this veterinary hospital. Almost all of them were MDR, and nearly half were XDR, posing a threat to animals and humans. In addition, the current hospital cleaning procedure proved ineffective. Future research should be conducted to determine the bacterial biofilm properties and bacterial sensitivity to certain detergents and disinfectants.202235698521
2657150.9997Investigating the Prevalence of Enterotoxin and Antibiotic Resistance in Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated From Meat and Edible Viscera of Broiler Chickens. BACKGROUND: The responsible for staph infection is methicillin-resistant Staphylococcus aureus (MRSA) which has a long and difficult treatment process due to resistance to this type of antibiotic. This study is designed to investigate the distribution and frequency of antibiotic-resistant genes and MRSA enterotoxins isolated from the meat and edible viscera of broiler chickens, which are responsible for pathogenicity in humans. MATERIALS AND METHODS: A total of 523 meat and edible viscera of broiler chicken collected from farms in Shahrekord, Iran. The antibiogram test of 142 MRSA isolates was performed by Kirby-Bauer diffusion disc. Sensitivity or resistance of MRSA was tested on 13 different antibiotics. DNA extracted from MRSA was screened by PCR technique for the presence of antibiotic-resistant and enterotoxin genes. RESULTS: Staphylococcus aureus (S. aureus) isolated with frequency of 51.05% (267 of 523). The presence of mecA gene in S. aureus was examined to detect the MRSA. The most antibiotic-resistance responsible genes and the pathogenic enterotoxin genes were identified. MRSA was identified by positive amplification of mecA in 53.18% (142 of 267) of S. aureus isolates. S. aureus antimicrobial resistance was most frequently noted against tetracycline (94.37%), ampicillin (88.73%) and penicillin (71.83%). Out of 51 examined isolates, 47 isolates exhibited the sea (92.15%), and 7 isolates exhibited the sej (13.72%). CONCLUSION: The results indicated high prevalence of MRSA in broilers, which is very worrying issue. In addition, in the present study, it was observed that due to the increase in the use of antibiotics in poultry farming, bacteria resistant to methicillin and other antibiotics have a high prevalence. Now, with the knowledge that the consumption of broiler chicken is very high all over the world and with the increasing trend of antibiotic consumption, this issue has become a concern at the global health level. The presence of antibiotic-resistance and enterotoxigenic genes in MRSA bacteria is a critical threat to human nutrition, making consuming contaminated meat and edible viscera of broiler chickens unsafe.202540613255
1287160.9997Frequently used therapeutic antimicrobials and their resistance patterns on Staphylococcus aureus and Escherichia coli in mastitis affected lactating cows. Mastitis is one of the most frequent and costly production diseases of dairy cattle. It is frequently treated with broad-spectrum antimicrobials. The objectives of this work were to investigate the prevalence of Staphylococcus aureus and Escherichia coli, find out the antimicrobials used in mastitis treatment, and explore the antimicrobial resistance profile including detection of resistance genes. Bacterial species and antimicrobial resistance genes were confirmed by the polymerase-chain reaction. A total of 450 cows were screened, where 23 (5.11%) and 173 (38.44%) were affected with clinical and sub-clinical mastitis, respectively. The prevalence of S. aureus was 39.13% (n = 9) and 47.97%(n = 83) while, E. coli was 30.43% (n = 7) and 15.60% (n = 27) in clinical and sub-clinical mastitis affected cows, respectively. The highest antimicrobials used for mastitis treatment were ciprofloxacin (83.34%), amoxycillin (80%) and ceftriaxone (76.67%). More than, 70% of S. aureus showed resistance against ampicillin, oxacillin, and tetracycline and more than 60% of E. coli exhibited resistance against oxacillin and sulfamethoxazole-trimethoprim. Selected antimicrobial resistance genes (mecA, tetK, tetL, tetM, tetA, tetB, tetC, sul1, sul2 and sul3) were identified from S. aureus and E. coli. Surprisingly, 7 (7.61%) S. aureus carried the mecA gene and were confirmed as methicillin-resistant S. aureus (MRSA). The most prevalent resistance genes were tetK 18 (19.57%) and tetL 13 (14.13%) for S. aureus, whereas sul1 16 (47.06%), tetA 12 (35.29%), sul2 11 (32.35%) and tetB 7 (20.59%) were the most common resistance genes in E. coli. Indiscriminate use of antimicrobials and the presence of multidrug-resistant bacteria suggest a potential threat to public health.202235291582
2348170.9997Characterization of Multidrug-Resistant Staphylococcus aureus Isolates and Comparison of Methods of Susceptibility to Vancomycin. S. aureus are among the main bacteria causing problems related to multidrug resistance in nosocomial infections. Therefore, it is necessary to carry out a reliable and rapid diagnosis for the identification of the bacteria and characterization of its susceptibility profile, especially vancomycin, which is an alternative treatment against multidrug-resistant (MDR) S. aureus. Thus, the goal of this study was to characterize isolates of S. aureus regarding the resistance and virulence and to check the susceptibility to vancomycin, through different methods, for comparative purposes. Seventeen antimicrobials were tested to assess the susceptibility profile. It was evaluated the presence of identification (nuc), resistance (mecA and blaZ), biofilm (icaA and icaD) and siderophore (sfaD and sbnD) genes. The susceptibility to vancomycin was evaluated by Minimum Inhibitory Concentration (MIC) by broth microdilution (BMD), E-test, commercial panel (Kit), and Phoenix equipment. Most S. aureus (93,33%) was classified as MDR. These isolates were 100% positive for nuc, mecA, icaA, icaD, and sfaD genes; 96.67% for sbnD and 33.33% for blaZ. In relation to BMD, all methods correctly classified the susceptibility of the isolates; however, regarding the exact MIC value for vancomycin, Phoenix showed agreement of 63.33%, E-test (33.33%) and Kit (26.66%). In conclusion, most of S. aureus was considered MDR. Also, they presented resistance, biofilm production, and siderophores genes, showing the pathogenic potential of these bacteria. Besides, the Phoenix test was considered the most effective, as it presents advantages, such as identification of the microorganism and a greater number of antimicrobials tested at a time.202236308600
2355180.9997Causative bacteria and antibiotic resistance in neonatal sepsis. BACKGROUND: Neonatal sepsis is characterised by bacteraemia and clinical symptoms caused by microorganisms and their toxic products. Gram negative bacteria are the commonest causes of neonatal Sepsis. The resistance to the commonly used antibiotics is alarmingly high. The major reason for emerging resistance against antibiotics is that doctors often do not take blood cultures before starting antibiotics. We have carried out this study to find out various bacteria causing neonatal sepsis and their susceptibility to antibiotics for better management of neonatal sepsis. METHODS: A total of 130 neonates with sepsis who were found to be blood culture positive were taken in this study. Culture/sensitivity was done, isolated organisms identified and their sensitivity/resistance was noted against different antibiotics. Data were arranged in terms of frequencies and percentage. RESULTS: Out of 130 culture proven cases of neonatal sepsis, gram negative bacteria were found in 71 (54.6%) cases and gram positive bacteria in 59 (45.4%) cases. Staphylococcus aureus was the most common bacteria found in 35 (26.9%) cases followed by Escherichia coli in 30 (23.1%) cases. Acinetobacter species, Staphylococcus epidermidis, Klebseila, Streptococci, Enterobacter cloacae and Morexella species were found in 17 (13.1%), 17 (13.1%), 13 (10%), 7 (5.4%), 6 (4.6%), and 5 (3.8%) cases respectively. In most of the cases causative organisms were found to be resistant to commonly used antibiotics like ampicillin, amoxicillin, cefotaxime, and ceftriaxone (77.7%, 81.5%, 63.1%, and 66.9% respectively). There was comparatively less (56.9%) resistance to ceftazidime. Gentamicin had resistance in 55.1% cases, while amikacin and tobramycin had relatively less resistance (17.4% and 34.8% cases respectively). Quinolones and imipenem had relatively less resistance. Vancomycin was found to be effective in 100% cases of Staphylococcus group. CONCLUSION: Staphylococcus aureus are the most common gram positive bacteria and Escherichia coli are the most common gram negative bacteria causing neonatal sepsis. Resistance to commonly used antibiotics is alarmingly increasing. Continued surveillance is mandatory to assess the resistance pattern at a certain level.201224669633
2350190.9997Antibiotic Resistance Profiles and MLST Typing of Staphylococcus Aureus Clone Associated with Skin and Soft Tissue Infections in a Hospital of China. OBJECTIVE: To analyze the antibiotic resistance profile, virulence genes, and molecular typing of Staphylococcus aureus (S. aureus) strains isolated in skin and soft tissue infections at the First Affiliated Hospital, Gannan Medical University, to better understand the molecular epidemiological characteristics of S. aureus. METHODS: In 2023, 65 S. aureus strains were isolated from patients with skin and soft tissue infections. Strain identification and susceptibility tests were performed using VITEK 2 and gram-positive bacteria identification cards. DNA was extracted using a DNA extraction kit, and all genes were amplified using polymerase chain reaction. Multilocus sequence typing (MLST) was used for molecular typing. RESULTS: In this study, of the 65 S. aureus strains were tested for their susceptibility to 16 antibiotics, the highest resistance rate to penicillin G was 95.4%. None of the staphylococcal isolates showed resistance to ceftaroline, daptomycin, linezolid, tigecycline, teicoplanin, or vancomycin. fnbA was the most prevalent virulence gene (100%) in S. aureus strains isolated in skin and soft tissue infections, followed by arcA (98.5%). Statistical analyses showed that the resistance rates of methicillin-resistant S. aureus isolates to various antibiotics were significantly higher than those of methicillin-susceptible S. aureus isolates. Fifty sequence types (STs), including 44 new ones, were identified by MLST. CONCLUSION: In this study, the high resistance rate to penicillin G and the high carrying rate of virulence gene fnbA and arcA of S.aureus were determine, and 44 new STs were identified, which may be associated with the geographical location of southern Jiangxi and local trends in antibiotic use. The study of the clonal lineage and evolutionary relationships of S. aureus in these regions may help in understanding the molecular epidemiology and provide the experimental basis for pathogenic bacteria prevention and treatment.202438933775