# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 5939 | 0 | 1.0000 | Resistance to antimicrobial agents of common bacteria isolated from Taiwan. Antimicrobial susceptibility of 11 commonly seen and/or important pathogenic bacteria isolated from the National Taiwan University Hospital in 1981 and 1992 was analysed. Oxacillin-resistance was most remarkable in Staphylococcus aureus. Its prevalence increased rapidly from 6.7% in 1981 to 49.7% in 1992. A high proportion of oxacillin-resistance was also found in coagulase-negative staphylococci, both in 1981 and in 1992. For Streptococcus pneumoniae, no penicillin-resistant nor erythromycin-resistant strain was found in 1981, but by 1992, 5.8% of the isolates were penicillin-resistant 42.3% erythromycin-resistant. Gentamicin-resistance was the most common problem in enterococci, with 70.6% resistance in 1992. As to Gram-negative bacteria, Enterobacter spp. demonstrated a high proportion of resistance to various antimicrobial agents: more than 72% susceptibility was found only for amikacin. Pseudomonas aeruginosa was also a highly resistant bacterium, with only 50 to 90% of susceptibility to various antipseudomonal agents. In Haemophilus influenzae, both ampicillin-resistance and chloramphenicol-resistance were remarkable, with 52.2% and 32.9% resistance, respectively, in 1992. | 1994 | 18611604 |
| 2363 | 1 | 0.9997 | Analysis 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. | 2023 | 37840716 |
| 2398 | 2 | 0.9997 | Antimicrobial-Resistant Enterococcus spp. in Wild Avifauna from Central Italy. Bacteria of the genus Enterococcus are opportunistic pathogens, part of the normal intestinal microflora of animals, able to acquire and transfer antimicrobial resistance genes. The aim of this study was to evaluate the possible role of wild avifauna as a source of antimicrobial-resistant enterococci. To assess this purpose, 103 Enterococcus spp. strains were isolated from the feces of wild birds of different species; they were tested for antimicrobial resistance against 21 molecules, vancomycin resistance, and high-level aminoglycosides resistance (HLAR). Furthermore, genes responsible for vancomycin, tetracycline, and HLAR were searched. E. faecium was the most frequently detected species (60.20% of isolates), followed by E. faecalis (34.95% of isolates). Overall, 99.02% of the isolated enterococci were classified as multidrug-resistant, with 19.41% extensively drug-resistant, and 2.91% possible pan drug-resistant strains. Most of the isolates were susceptible to amoxicillin/clavulanic acid (77.67%) and ampicillin (75.73%), with only 5.83% of isolates showing an ampicillin MIC ≥ 64 mg/L. HLAR was detected in 35.92% of isolates, mainly associated with the genes ant(6)-Ia and aac(6')-Ie-aph(2″)-Ia. Few strains (4.85%) were resistant to vancomycin, and the genes vanA and vanB were not detected. A percentage of 54.37% of isolates showed resistance to tetracycline; tet(M) was the most frequently detected gene in these strains. Wild birds may contribute to the spreading of antimicrobial-resistant enterococci, which can affect other animals and humans. Constant monitoring is essential to face up to the evolving antimicrobial resistance issue, and monitoring programs should include wild avifauna, too. | 2022 | 35884106 |
| 2362 | 3 | 0.9997 | Distribution of pathogenic bacteria and antimicrobial sensitivity of eye infections in Suzhou. AIM: To investigate the types of bacteria in patients with eye infections in Suzhou and their drug resistance to commonly used antibacterial drugs. METHODS: The clinical data of 155 patients were retrospectively collected in this study, and the pathogenic bacteria species and drug resistance of each pathogenic bacteria were analyzed. RESULTS: Among the 155 patients (age from 12 to 87 years old, with an average age of 57, 99 males and 56 females) with eye infections (160 eyes: 74 in the left eye, 76 in the right eye and 5 in both eyes, all of which were exogenous), 71 (45.81%) strains were gram-positive bacteria, 23 (14.84%) strains were gram-negative bacteria and 61 (39.35%) strains were fungi. Gram-positive bacteria were highly resistant to penicillin and erythromycin (78.87% and 46.48% respectively), but least resistant to vancomycin at 0. Gram-negative bacteria were highly resistant to cefoxitin and compound sulfamethoxazole (100% and 95.65% respectively), but least resistant to meropenem at 0. Comparison of the resistance of gram-positive and gram-negative bacteria to some drugs revealed statistically significant differences (P<0.05) in the resistance of both to cefoxitin, cotrimoxazole, levofloxacin, cefuroxime, ceftriaxone and ceftazidime, and both had higher rates of resistance to gram-negative bacteria than to gram-positive bacteria. The distribution of bacterial infection strains showed that Staphylococcus epidermidis was the most common strain in the conjunctiva, cornea, aqueous humor or vitreous body and other eye parts. Besides, Fusarium and Pseudomonas aeruginosa were also among the most common strains of conjunctival and corneal infections. CONCLUSION: Gram-positive bacteria are the dominant bacteria in eye infections, followed by gram-negative bacteria and fungi. Considering the resistance of gram-negative bacteria to multiple drugs, monitoring of bacteria should be strengthened in eye bacterial infections for effective prevention and control to reduce complications caused by eye infections. | 2024 | 38638249 |
| 2146 | 4 | 0.9997 | Study of aminoglycoside resistance genes in enterococcus and salmonella strains isolated from ilam and milad hospitals, iran. BACKGROUND: Aminoglycosides are a group of antibiotics that have been widely used in the treatment of life-threatening infections of Gram-negative bacteria. OBJECTIVES: This study aimed to evaluate the frequency of aminoglycoside resistance genes in Enterococcus and Salmonella strains isolated from clinical samples by PCR. MATERIALS AND METHODS: In this study, 140 and 79 isolates of Enterococcus and Salmonella were collected, respectively. After phenotypic biochemical confirmation, 117 and 77 isolates were identified as Enterococcus and Salmonella, respectively. After the biochemical identification of the isolates, antibiotic susceptibility for screening of resistance was done using the Kirby-Bauer method for gentamicin, amikacin, kanamycin, tobramycin and netilmycin. DNA was extracted from resistant strains and the presence of acc (3)-Ia, aac (3')-Ib, acc (6)-IIa ,16SrRNA methylase genes (armA and rat) was detected by PCR amplification using special primers and positive controls. RESULTS: Enterococcus isolates have the highest prevalence of resistance to both kanamycin and amikacin (68.4%), and Salmonella isolates have the highest prevalence of resistance against kanamycin (6.9%). Ninety-three and 26 isolates of Enterococcus and Salmonella at least were resistant against one of the aminoglycosides, respectively. Moreover, 72.04%, 66.7%, and 36.6% of the resistant strains of Enterococcus had the aac (3')-Ia, aac (3')-IIa, and acc (6')-Ib genes, respectively. None of the Salmonella isolates have the studied aminoglycoside genes. CONCLUSIONS: Our results indicate that acetylation genes have an important role in aminoglycoside resistance of the Enterococcus isolates from clinical samples. Moreover, Salmonella strains indicate very low level of aminoglycoside resistance, and aminoglycoside resistance genes were not found in Salmonella isolates. These results indicate that other resistance mechanisms, including efflux pumps have an important role in aminoglycoside resistance of Salmonella. | 2015 | 26034551 |
| 2397 | 5 | 0.9997 | Antimicrobial resistance in Enterococcus strains isolated from healthy domestic dogs. Enterococci are opportunistic bacteria that cause severe infections in animals and humans, capable to acquire, express, and transfer antimicrobial resistance. Susceptibility to 21 antimicrobial agents was tested by the disk diffusion method in 222 Enterococcus spp. strains isolated from the fecal samples of 287 healthy domestic dogs. Vancomycin and ampicillin minimum inhibitory concentrations (MICs) and high-level aminoglycoside resistance (HLAR) tests were also performed. Isolates showed resistance mainly to streptomycin (88.7%), neomycin (80.6%), and tetracycline (69.4%). Forty-two (18.9%) isolates showed an HLAR to streptomycin and 15 (6.7%) to gentamicin. Vancomycin and ampicillin MIC values showed 1 and 18 resistant strains, respectively. One hundred and thirty-six (61.2%) strains were classified as multidrug resistant and six (2.7%) strains as possibly extensively drug-resistant bacteria. Enterococcus faecium and Enterococcus faecalis were the most prevalent antimicrobial resistant species. Companion animals, which often live in close contact with their owners and share the same environment, represent a serious source of enterococci resistant to several antibiotics; for this reason, they may be a hazard for public health by providing a conduit for the entrance of resistance genes into the community. | 2017 | 27976593 |
| 5428 | 6 | 0.9997 | Antimicrobial resistance and prevalence of resistance genes of obligate anaerobes isolated from periodontal abscesses. BACKGROUND: This study attempts to determine the antimicrobial resistance profiles of obligate anaerobic bacteria that were isolated from a periodontal abscess and to evaluate the prevalence of resistance genes in these bacteria. METHODS: Forty-one periodontal abscess samples were cultivated on selective and non-selective culture media to isolate the oral anaerobes. Their antibiotic susceptibilities to clindamycin, doxycycline, amoxicillin, imipenem, cefradine, cefixime, roxithromycin, and metronidazole were determined using the agar dilution method, and polymerase chain reaction assays were performed to detect the presence of the ermF, tetQ, nim, and cfxA drug resistance genes. RESULTS: A total of 60 different bacterial colonies was isolated and identified. All of the isolates were sensitive to imipenem. Of the strains, 6.7%, 13.3%, 16.7%, and 25% were resistant to doxycycline, metronidazole, cefixime, and amoxicillin, respectively. The resistance rate for both clindamycin and roxithromycin was 31.7%. Approximately 60.7% of the strains had the ermF gene, and 53.3% of the amoxicillin-resistant strains were found to have the cfxA gene. Two nim genes that were found in eight metronidazole-resistant strains were identified as nimB. CONCLUSIONS: In the present study, the Prevotella species are the most frequently isolated obligate anaerobes from periodontal abscesses. The current results show their alarmingly high resistance rate against clindamycin and roxithromycin; thus, the use of these antibiotics is unacceptable for the empirical therapy of periodontal abscesses. A brief prevalence of four resistance genes in the anaerobic bacteria that were isolated was also demonstrated. | 2014 | 23659425 |
| 2359 | 7 | 0.9997 | Virulence 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. | 2021 | 34357963 |
| 5536 | 8 | 0.9997 | Phenotypic and genetic characterization of multidrug-resistant Staphylococcus aureus in the tropics of Southeast Asia. Antibiotic resistance has become a major public health problem throughout the world. The presence of antibiotic-resistant bacteria such as Staphylococcus aureus and antibiotic resistance genes (ARGs) in hospital wastewater is a cause for great concern today. In this study, 276 Staph. aureus isolates were recovered from hospital wastewater samples in Malaysia. All of the isolates were screened for susceptibility to nine different classes of antibiotics: ampicillin, ciprofloxacin, gentamicin, kanamycin, erythromycin, vancomycin, trimethoprim and sulfamethoxazole, chloramphenicol, tetracycline and nalidixic acid. Screening tests showed that 100 % of Staph.aureus isolates exhibited resistance against kanamycin, vancomycin, trimethoprim and sulfamethoxazole and nalidixic acid. Additionally, 91, 87, 50, 43, 11 and 8.7 % of isolates showed resistance against erythromycin, gentamicin, ciprofloxacin, ampicillin, chloramphenicol and tetracycline, respectively. Based on these results, 100 % of isolates demonstrated multidrug-resistant (MDR) characteristics, displaying resistance against more than three classes of antibiotics. Of 276 isolates, nine exhibited resistance to more than nine classes of tested antibiotics; these were selected for antibiotic susceptibility testing and examined for the presence of conserved ARGs. Interestingly, a high percentage of the selected MDR Staph.aureus isolates did not contain conserved ARGs. These results indicate that non-conserved MDR gene elements may have already spread into the environment in the tropics of Southeast Asia, and unique resistance mechanisms against several antibiotics may have evolved due to stable, moderate temperatures that support growth of bacteria throughout the year. | 2016 | 27902427 |
| 1273 | 9 | 0.9997 | Trimethoprim resistance in gram-negative bacteria isolated in South Africa. Resistance to trimethoprim was surveyed in 2914 Gram-negative bacteria isolated in three hospitals in South Africa. Bacteria were collected from November 1986 to January 1987 and the minimum inhibitory concentration (MIC) of trimethoprim for each isolate was determined. The overall resistance rate (MIC greater than 8 mg/l) was 56.2%, and high-level resistance (MIC greater than 1024 mg/l) occurred in 24.0% of the total. The frequency of resistance in isolates of Enterobacteriaceae was 48.5% (MIC greater than 8 mg/l). Of the organisms isolated from urine specimens, 49.1% were resistant to trimethoprim, 71.8% of these being highly resistant. Investigation of 36 isolates for the presence of the type I and/or type II dihydrofolate reductase genes showed that eight isolates reacted with the type I probe but none with the type II probe. | 1989 | 2621180 |
| 2301 | 10 | 0.9997 | Korean Nationwide Surveillance of Antimicrobial Resistance of bacteria in 1997. Antimicrobial-resistant bacteria are known to be prevalent in tertiary-care hospitals in Korea. Twenty hospitals participated to this surveillance to determine the nationwide prevalence of resistance bacteria in 1997. Seven per cent and 26% of Escherichia coli and Klebsiella pneumoniae were resistant to 3rd-generation cephalosporin. Increased resistance rates, 19% of Acinetobacter baumannii to ampicillin/sulbactam, and 17% of Pseudomonas aeruginoa to imipenem, were noted. The resistance rate to fluoroquinolone rose to 24% in E. coli, 56% in A. baumannii and 42% in P. aeruginosa. Mean resistance rates were similar in all hospital groups: about 17% of P. aeruginosa to imipenem, 50% of Haemophilus influenzae to ampicillin, 70% of Staphylococcus aureus to methicillin, and 70% of pneumococci to penicillin. In conclusion, nosocomial pathogens and problem resistant organisms are prevalent in smaller hospitals too, indicating nosocomial spread is a significant cause of the increasing prevalence of resistant bacteria in Korea. | 1998 | 10097685 |
| 2701 | 11 | 0.9997 | Detection of antibiotic-resistant bacteria and their resistance genes from houseflies. BACKGROUND AND AIM: Houseflies (Musca domestica) are synanthropic insects which serve as biological or mechanical vectors for spreading multidrug-resistant bacteria responsible for many infectious diseases. This study aimed to detect antibiotic-resistant bacteria from houseflies, and to examine their resistance genes. MATERIALS AND METHODS: A total of 140 houseflies were captured using sterile nylon net from seven places of Mymensingh city, Bangladesh. Immediately after collection, flies were transferred to a sterile zipper bag and brought to microbiology laboratory within 1 h. Three bacterial species were isolated from houseflies, based on cultural and molecular tests. After that, the isolates were subjected to antimicrobial susceptibility testing against commonly used antibiotics, by the disk diffusion method. Finally, the detection of antibiotic resistance genes tetA, tetB, mcr-3, mecA, and mecC was performed by a polymerase chain reaction. RESULTS: The most common isolates were Staphylococcus aureus (78.6%), Salmonella spp., (66.4%), and Escherichia coli (51.4%). These species of bacteria were recovered from 78.3% of isolates from the Mymensingh Medical College Hospital areas. Most of the isolates of the three bacterial species were resistant to erythromycin, tetracycline, penicillin and amoxicillin and were sensitive to ciprofloxacin, ceftriaxone, chloramphenicol, gentamicin, and azithromycin. Five antibiotic resistance genes of three bacteria were detected: tetA, tetB, mcr-3, and mecA were found in 37%, 20%, 20%, and 14% isolates, respectively, and no isolates were positive for mecC gene. CONCLUSION: S. aureus, Salmonella spp., and E. coli with genetically-mediated multiple antibiotic resistance are carried in houseflies in the Mymensingh region. Flies may, therefore, represent an important means of transmission of these antibiotic-resistant bacteria, with consequent risks to human and animal health. | 2020 | 32255968 |
| 2355 | 12 | 0.9997 | Causative 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. | 2012 | 24669633 |
| 2673 | 13 | 0.9997 | Geographical and ecological analysis of resistance, coresistance, and coupled resistance to antimicrobials in respiratory pathogenic bacteria in Spain. A multicenter susceptibility surveillance (the S.A.U.C.E. project) including 2,721 Streptococcus pneumoniae, 3,174 Streptococcus pyogenes, and 2,645 Haemophilus influenzae consecutive isolates was carried out in 25 hospitals all over Spain from November 2001 to October 2002 to evaluate the current epidemiology of resistance of the main bacteria involved in community-acquired respiratory tract infections. Susceptibility testing was performed in a single centralized laboratory by a broth microdilution method. The prevalence of resistant S. pneumoniae strains was 0.4% for cefotaxime, 4.4% for amoxicillin and amoxicillin-clavulanic acid, 25.6% for cefuroxime-axetil, 34.5% for erythromycin, clarithromycin, and azithromycin, and 36.0% for cefaclor. Phenotypes of resistance to erythromycin were MLS(B) (macrolide-lincosamide-streptogramin B) in 89.9% (gene ermB) and M (macrolide) in 9.7% of cases (gene mefA). No strain harbored both genes simultaneously. Serotypes 19, 6, 23, 14, and 3 were the most prevalent, accounting for 54.6% of the total isolates. Resistance to macrolides seems to be the most alarming point, since among penicillin-susceptible isolates it reached 15.1% compared to 55.8% among penicillin-resistant strains. Geographically, a number of regions had rates of erythromycin resistance above 40% (even higher in children). Resistance to erythromycin was also high in S. pyogenes isolates: mean regional 33.2%, beta-lactamase-producing H. influenzae were 20%, whereas 4.4% had a beta-lactamase-negative, ampicillin-resistant phenotype. We highlight the importance of different geographical frequencies of coresistance (associations of resistance to different drugs within the same species) and coupled resistance (association of resistance between different species) probably resulting from different local coselective events. | 2005 | 15855520 |
| 2356 | 14 | 0.9997 | Occurrence of Multiple-Drug Resistance Bacteria and Their Antimicrobial Resistance Patterns in Burn Infections from Southwest of Iran. Burn infection continues to be a major issue of concern globally and causes more harm to developing countries. This study aimed to identify the aerobic bacteriological profiles and antimicrobial resistance patterns of burn infections in three hospitals in Abadan, southwest Iran. The cultures of various clinical samples obtained from 325 burn patients were investigated from January to December 2019. All bacterial isolates were identified based on the standard microbiological procedures. Antibiotic susceptibility tests were performed according to the CLSI. A total of 287 bacterial species were isolated from burn patients. Pseudomonas aeruginosa was the most frequent bacterial isolate in Gram-negative bacteria and S. epidermidis was the most frequent species isolated in Gram-positive bacteria. The maximum resistance was found to ampicillin, gentamicin, ciprofloxacin, while in Gram-negative bacteria, the maximum resistance was found to imipenem, gentamicin, ciprofloxacin, ceftazidime, and amikacin. The occurrence of multidrug resistance phenotype was as follows: P. aeruginosa (30.3%), Enterobacter spp (11.1%), Escherichia coli (10.5%), Citrobacter spp (2.1%), S. epidermidis (2.8%), S. aureus, and S. saprophyticus (0.7%). Owing to the diverse range of bacteria that cause burn wound infection, regular investigation, and diagnosis of common bacteria and their resistance patterns is recommended to determine the proper antibiotic regimen for appropriate therapy. | 2022 | 34236077 |
| 2440 | 15 | 0.9997 | Molecular basis of resistance to macrolides, lincosamides and streptogramins in Staphylococcus hominis strains isolated from clinical specimens. Coagulase-negative staphylococci (CoNS) are the most frequently isolated bacteria from the blood and the predominant cause of nosocomial infections. Macrolides, lincosamides and streptogramin B (MLSB) antibiotics, especially erythromycin and clindamycin, are important therapeutic agents in the treatment of methicillin-resistant staphylococci infections. Among CoNS, Staphylococcus hominis represents the third most common organism. In spite of its clinical significance, very little is known about its mechanisms of resistance to antibiotics, especially MLSB. Fifty-five S. hominis isolates from the blood and the surgical wounds of hospitalized patients were studied. The erm(C) gene was predominant in erythromycin-resistant S. hominis isolates. The methylase genes, erm(A) and erm(B), were present in 15 and 25% of clinical isolates, respectively. A combination of various erythromycin resistance methylase (erm) genes was detected in 15% S. hominis isolates. The efflux gene msr(A) was detected in 18% of isolates, alone in four isolates, and in different combinations in a further six. The lnu(A) gene, responsible for enzymatic inactivation of lincosamides was carried by 31% of the isolates. No erythromycin resistance that could not be attributed to the genes erm(A), erm(B), erm(C) and msr(A) was detected. In S. hominis, 75 and 84%, respectively, were erythromycin resistant and clindamycin susceptible. Among erythromycin-resistant S. hominis isolates, 68% of these strains showed the inducible MLSB phenotype. Four isolates harbouring the msr(A) genes alone displayed the MSB phenotype. These studies indicated that resistance to MLSB in S. hominis is mostly based on the ribosomal target modification mechanism mediated by erm genes, mainly the erm(C), and enzymatic drug inactivation mediated by lnu(A). | 2016 | 26253583 |
| 2389 | 16 | 0.9997 | Antibiotic Resistance of LACTOBACILLUS Strains. The study provides phenotypic and molecular analyses of the antibiotic resistance in 20 Lactobacillus strains including 11 strains newly isolated from fermented plant material. According to the results of disc diffusion method, 90% of tested lactobacilli demonstrated sensitivity to clindamycin and 95% of strains were susceptible to tetracycline, erythromycin, and rifampicin. Ampicillin and chloramphenicol were found to inhibit all bacteria used in this study. The vast majority of tested strains revealed phenotypic resistance to vancomycin, ciprofloxacin, and aminoglycosides. Most of Lactobacillus strains showed high minimum inhibitory concentrations (MICs) of cefotaxime, ceftriaxone, and cefazolin and therefore were considered resistant to cephalosporins. All the strains exhibited multidrug resistance. The occurrence of resistance genes was associated with phenotypic resistance, with the exception of phenotypically susceptible strains that contained genes for tetracycline (tetK, tetL) and erythromycin (ermB, mefA) resistance. The vanX gene for vancomycin resistance was among the most frequently identified among the lactobacilli (75% of strains), but the occurrence of the parC gene for ciprofloxacin resistance was sporadic (20% of strains). Our results mainly evidence the intrinsic nature of the resistance to aminoglycosides in lactobacilli, though genes for enzymatic modification of streptomycin aadA and aadE were found in 20% of tested strains. The occurrence of extended spectrum beta-lactamases (ESBL) was unknown in Lactobacillus, but our results revealed the blaTEM gene in 80% of strains, whereas blaSHV and blaOXA-1 genes were less frequent (20% and 15% of strains, respectively). | 2019 | 31555856 |
| 2390 | 17 | 0.9997 | Identification, antimicrobial susceptibility, and virulence factors of Enterococcus spp. strains isolated from Camels in Canary Islands, Spain. This study investigated the presence of Enterococcus spp. strains in camel faeces, their virulence factors, and resistance to the antibiotics commonly used as therapy of enterococcal infections. One hundred and seventy three Enterococcus strains were isolated and identified to species level using polymerase chain reaction (PCR). Susceptibility to 11 antimicrobials was determined by disk diffusion method. Minimal Inhibitory Concentrations (MIC) of penicillin, ampicillin, vancomycin, teicoplanin, gentamicin, and streptomycin were all determined. Genes encoding resistance to vancomycin, tetracycline, and erythromycin as well as genes encoding some virulence factors were identified by PCR. Enterococcus hirae (54.3%) and Enterococcus faecium (25.4%) were the species most frequently isolated. None of the strains were resistant to vancomycin, teicoplanin, ampicillin or showed high level aminoglycoside resistance (HLAR). Strains resistant to rifampicin (42.42%) were those most commonly found followed those resistant to trimethoprim - sulfamethoxazole (33.33%). The genes tetM, tetL, vanC1, and vanC2-C3 were detected in some strains. Virulence genes were not detected. Monitoring the presence of resistant strains of faecal enterococci in animal used with recreational purposes is important to prevent transmission of those strains to humans and to detect resistance or virulence genes that could be transferred to other clinically important bacteria. | 2015 | 26455369 |
| 5538 | 18 | 0.9997 | Phenotypic and genotypic antimicrobial susceptibility pattern of Streptococcus spp. isolated from cases of clinical mastitis in dairy cattle in Poland. Mastitis of dairy cattle is one of the most frequently diagnosed diseases worldwide. The main etiological agents of mastitis are bacteria of the genus Streptococcus spp., in which several antibiotic resistance mechanisms have been identified. However, detailed studies addressing this problem have not been conducted in northeastern Poland. Therefore, the aim of our study was to analyze, on phenotypic and genotypic levels, the antibiotic resistance pattern of Streptococcus spp. isolated from clinical cases of mastitis from dairy cattle in this region of Poland. The research was conducted using 135 strains of Streptococcus (Streptococcus uberis, n = 53; Streptococcus dysgalactiae, n = 41; Streptococcus agalactiae, n = 27; other streptococci, n = 14). The investigation of the antimicrobial susceptibility to 8 active substances applied in therapy in the analyzed region, as well as a selected bacteriocin (nisin), was performed using the minimum inhibitory concentration method. The presence of selected resistance genes (n = 14) was determined via PCR. We also investigated the correlation between the presence of resistance genes and the antimicrobial susceptibility of the examined strains in vitro. The highest observed resistance of Streptococcus spp. was toward gentamicin, kanamycin, and tetracycline, whereas the highest susceptibility occurred toward penicillin, enrofloxacin, and marbofloxacin. Additionally, the tested bacteriocin showed high efficacy. The presence of 13 analyzed resistance genes was observed in the examined strains [gene mef(A) was not detected]. In most strains, at least one resistance gene, mainly responsible for resistance to tetracyclines [tet(M), tet(K), tet(L)], was observed. However, a relationship between the presence of a given resistance gene and antimicrobial susceptibility on the phenotypic level was not always observed. | 2017 | 28601447 |
| 5786 | 19 | 0.9997 | Characterisation of Bacterial Isolates from Infected Post-Operative Patients in a Malaysian Tertiary Heart Care Centre. Several bacterial species cause post-operative infections, which has been a critical health concern among hospital patients. Our study in this direction is a much-needed exploratory study that was carried out at the National Heart Institute (IJN) of Malaysia to examine the virulence properties of causative bacteria obtained from postoperative patients. The bacterial isolates and data were provided by the IJN. Antibiotic resistance gene patterns, and the ability to form biofilm were investigated for 127 isolates. Klebsiella pneumoniae (36.2%) was the most common isolate collected, which was followed by Pseudomonas aeruginosa (26%), Staphylococcus aureus (23.6%), Streptococcus spp. (8.7%) and Acinetobacter baumannii (5.5%). There were 49 isolates that showed the presence of multidrug resistance genes. The mecA gene was surprisingly found in methicillin-susceptible S. aureus (MSSA), which also carried the ermA gene from those erythromycin-susceptible strains. The phenotypic antibiotic resistance profiles varied greatly between isolates. Findings from the biofilm assay revealed that 44 of the 127 isolates demonstrated the ability to produce biofilms. Our findings provide insights into the possibility of some of these bacteria surviving under antibiotic stress, and some antibiotic resistance genes being silenced. | 2021 | 34574752 |