Susceptibility To Antimicrobial Agents Research Articles

Epidemiological cut-off values for Yersina ruckeri disc diffusion data generated by a standardised method.

In order to establish the meaning of data generated in antimicrobial agent susceptibility tests, it is necessary to develop internationally harmonised interpretive criteria. Currently, such criteria have not been developed for data generated in studies of the susceptibility of the fish pathogen Yersinia ruckeri. This work generated the data that would be required to set epidemiological cut-off values for the susceptibility data of this species that had been generated using a standardised disc diffusion method that specified the use of Mueller Hinton agar and incubation at 22°C for 24-28 h. Using this method, sets of inhibition zones data for 4 antimicrobial agents were generated by 3 independent laboratories. The data from these laboratories were aggregated and analysed using the statistically based normalised resistance interpretation. For ampicillin, florfenicol, oxytetracycline and trimethoprim-sulfamethoxazole the cut-off values calculated by this analysis were ≥16, ≥23, ≥24 and ≥30 mm, respectively. Evidence is presented demonstrating that the data for these 4 agents was of sufficient quantity and quality that they could be used by the relevant authorities to set internationally harmonised, consensus epidemiological cut-off values for Y. ruckeri.

Analysis of NDM-1 and IMP-8 carbapenemase producing Raoultella planticola clinical isolates.

Object of our study was to analyze the carriage of resistance genes in carbapenem-resistant Raoultella planticola (CRRP) by whole genome sequencing (WGS). Three strains of CRRP (named WF0027, WF3597 and WF3648) were collected for clinical analysis and susceptibility of antimicrobial agents was determined. The WGS of three strains was done by Illumina platform and strain identification was performed by average nucleotide identity, and the antibiotic resistance genes carried by the three strains were detected by ABRicate software. Whole genome data of 46 CRRP strains were downloaded from the National Center for Biotechnology Information (NCBI) database, and the evolutionary tree was constructed by genomic single nucleotide polymorphism together with this study strains. Antimicrobial susceptibility testing revealed that WF3597 and WF3648 were susceptible to tigecycline and colistin, while exhibited resistance to 24 antimicrobial agents. WF0027 was resistant to 18 antimicrobial agents. A total of 25 resistance genes were identified using ABRicate software. WF0027 carried blaIMP-8, whereas WF3597 and WF3648 carried blaNDM-1 carbapenem resistance gene. As predicted by the PlasmidFinder, WF3597 and WF3648 carried one plasmid IncFII(p14)_1_p14, whereas WF0027 carried five plasmids. Evolutionary tree results show all strains are clustered into six groups, the strains WF3597 and WF3648 belonged to the same evolutionary group (E clade) and WF0027 belonged to the F clade. Three CRRP strains in our study carried carbapenem resistance genes (blaNDM-1 or blaIMP-8) and were resistant to multiple antimicrobial agents, posing a significant challenge for clinical treatment.

An investigation of clinical characteristics and antimicrobial agent susceptibility patterns in clinical Comamonas testosteroni isolates: An increasingly prevalent nosocomial pathogen

BackgroundComamonas testosteroni is a gram-negative bacillus, known before 1987 as Pseudomonas testosteroni. Although considered as a rare pathogen, its frequency has been increasing. Data regarding its antibiotic susceptibility are insufficient. To date, forty-four cases have been reported in the literature. In this study, we identified the C. testosteroni infections observed in our hospital and evaluated their antimicrobial agent susceptibility patterns compared with cases reported in the literature. MethodsFor the purposes of the present study, patients admitted to hospital between November 2019 and December 2020 were screened. Those with clinical and laboratory signs of infection with positive C. testosteroni growth in culture were enrolled. Clinical isolates obtained from the samples processed in accordance with standard microbiological examination procedures in our laboratory were defined by MALDI-TOF mass spectrometry with 99.9% probability as C. testosteroni. ResultsC testosteroni infection was detected between November 2019 and December 2020 in eight patients in our hospital. Six of them had a bloodstream infection (BSI), one had pneumonia, and one had urinary tract infection due to C. testosteroni. Coexistence of COVID-19 was detected in four patients. Six out of the eight cases with BSI had hospital-acquired infection and all of the infections were healthcare-associated. When antimicrobial agent susceptibility results reported in the literature were evaluated in combination with the current results, ceftazidime and meropenem were found to be the most susceptible agents (96.1% and 80%, respectively). ConclusionsThe frequency of nosocomial C. testosteroni infections and resistance to antimicrobial agents are gradually increasing. While resistance to carbapenems is on the upswing, third-generation cephalosporins are still seen as suitable treatment options.

Clinical manifestations and antimicrobial susceptibility of Nocardia species at a tertiary hospital in Taiwan, 2011–2020

BackgroundThe study aimed to assess the clinical characteristics of patients with nocardiosis, to evaluate the in vitro susceptibility of antimicrobial agents against Nocardia species, and to explore changes in antimicrobial susceptibilities in this era of multidrug resistance. MethodsNocardia isolates were identified to the species level using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA, hsp65, and secA1 gene sequencing, and minimum inhibitory concentrations (MICs) of 15 antimicrobial agents were assessed with the broth microdilution method. ResultsEighty-nine isolates from 68 patients were identified to species level. The most common species were Nocardia brasiliensis (n = 28, 31.5%), followed by N. farcinica (n = 24, 27%) and N. cyriacigeorgica (n = 16, 18%). Skin and soft tissue were the most common sites of nocardiosis. In multivariate analysis, cutaneous infection (OR, 0.052; p = 0.009), immunosuppressant use (OR, 16.006; p = 0.013) and Charlson combidity index (OR, 1.522; p = 0.029) were significant predictors for death. In total, 98.9% isolates were susceptible to trimethoprim-sulfamethoxazole and linezolid. Further, the MIC range and resistance rate of all Nocardia species to ceftriaxone, imipenem, and amoxicillin-clavulanic acid were found to generally increase over time. ConclusionConsidering that trimethoprim-sulfamethoxazole is effective against most Nocardia species, it is the antibiotic of choice in Taiwan. Besides, amikacin, tigecycline, and linezolid showed high activity against Nocardia species and are thus good alternatives or additional therapies to treat nocardiosis, depending on patient's underlying conditions and site of infection.

Susceptibilities of Yersinia pestis to Twelve Antimicrobial Agents in China

Objective: Streptomycin is the preferred choice for therapy of plague in China and other countries. However, Yersinia pestis exhibiting plasmid-mediated antimicrobial agent–resistant traits had been reported in Madagascar. In this study, we evaluated the susceptibility of traditional or newer antimicrobial agents used for treatment and/or prophylaxis of plague. Methods: Following Clinical and Laboratory Standards Institute (CLSI) recommendations, the susceptibility of 12 antimicrobial agents was evaluated by the agar microdilution method in 1,012 strains of Y. pestis isolated from 1943 to 2017 in 12 natural plague foci in China. Results: One clinical Y. pestis isolate (S19960127) was found to be highly resistant to streptomycin, while the strain was still sensitive to other 11 antibiotics, that is, ciprofloxacin, ofloxacin, kanamycin, chloramphenicol, ampicillin, ceftriaxone, cefuroxime, trimethoprim-sulfamethoxazole, tetracycline, spectinomycin and moxifloxacin. The remaining 1,011 Y. pestis strains in this study demonstrated susceptibility to the above-mentioned 12 antimicrobial agents. Conclusion: Antimicrobial sensitivity surveillance of Y. pestis isolates, including dynamic monitoring of streptomycin resistance during various clinical plague treatments, should be carried out routinely.

Antibiotic Resistance and Virulence Profiles of Escherichia coli Strains Isolated from Wild Birds in Poland.

Wild animals are increasingly reported as carriers of antibiotic-resistant and pathogenic bacteria including Enterobacteriaceae. However, the role of free-living birds as reservoirs for potentially dangerous microbes is not yet thoroughly understood. In our work, we examined Escherichia coli strains from wild birds in Poland in relation to their antimicrobial agents susceptibility, virulence and phylogenetic affiliation. Identification of E. coli was performed using MALDI-TOF mass spectrometry. The antibiotic susceptibility of the isolates was determined by the broth microdilution method, and resistance and virulence genes were detected by PCR. E. coli bacteria were isolated from 32 of 34 samples. The strains were most often classified into phylogenetic groups B1 (50%) and A (25%). Resistance to tetracycline (50%), ciprofloxacin (46.8%), gentamicin (34.3%) and ampicillin (28.1%) was most frequently reported, and as many as 31.2% of E. coli isolates exhibited a multidrug resistance phenotype. Among resistance genes, sul2 (31.2% of isolates) and blaTEM (28.1%) were identified most frequently, while irp-2 (31.2%) and ompT (28.1%) were the most common virulence-associated genes. Five strains were included in the APEC group. The study indicates that wild birds can be carriers of potentially dangerous E. coli strains and vectors for the spread of resistant bacteria and resistance determinants in the environment.

Efficacy of Tegoprazan for Improving the Susceptibility of Antimicrobial Agents against Antibiotic-Resistant Helicobacter pylori.

Background/AimsFavorable outcomes of potassium-competitive acid blocker (PCAB)-containing eradication therapy have been reported. In fact, tegoprazan, a recently developed PCAB, was presumed to show good eradication efficacy even for resistant Helicobacter pylori. We aimed to investigate the anti-H. pylori efficacy of tegoprazan compared with that of vonoprazan.MethodsA total of 220 resistant clinical H. pylori isolates were utilized. The anti-H. pylori efficacy of PCABs was determined by evaluating the minimum inhibitory concentrations (MICs) of clarithromycin, fluoroquinolone, metronidazole, and amoxicillin in combination with vonoprazan or tegoprazan by the agar dilution method. The impact of the mutations responsible for resistance development, such as 23S rRNA, gyrA, rdxA, frxA, and pbp1 mutations, was also analyzed.ResultsH. pylori growth was significantly inhibited in a medium containing 1 μg/mL clarithromycin with tegoprazan (128 μg/mL). The MICs of clarithromycin (46.3%), fluoroquinolone (46.7%), metronidazole (55.6%), and amoxicillin (34.5%) against resistant H. pylori isolates improved after tegoprazan administration. Tegoprazan demonstrated more frequent susceptibility acquisition with metronidazole than with vonoprazan (20.6% vs 4.7%, p=0.014). However, there were no significant differences depending on the mutational status of each antimicrobial agent.ConclusionsTegoprazan administration may improve the susceptibility of antimicrobial-resistant H. pylori, independent of acid suppression.

Bacterial Pattern and Susceptibility of Antimicrobial Agents in Cancer Patient with Infection

Introduction: Cancer patients are most vulnerable to develop infection during anticancer therapy which could be life threatening. Therefore, prompt administration of appropriate antimicrobial drug therapy is often essential to prevent mortality and morbidity in such patients. Spectrum of the infection causing organisms is continuously changing throughout the world along with their susceptibility to antimicrobials drugs. Aims: The aims of the study were to identify the bacterial pattern and their susceptibility to antimicrobials in cancer patients with infection and to help develop a guideline for the rational and appropriate use of antimicrobial in these patients. Materials and methods: It was an observational study conducted from January 2013 to December 2014 at the National Institute of Cancer Research and Hospital (NICRH), Mohakhali, Dhaka. We evaluated 517 blood and other specimens from cancer patients of both sexes and all ages under anticancer therapy suspected of having infection. Result: Blood culture was done in 53 patients of them 8 (15.09%) were proved to be culture positive. In case of urine and wound culture the rates of positivity were 37.79% & 73.98% respectively. In suspected cases culture for anaerobic organism was done but no such organism was found. Major isolated organisms in different cultures were E. coli, Staphylococcus aureus, Pseudomonas and Proteus. Imipenem, gentamicin, cotrimoxazole were the most sensitive antibiotics. However, in most cases amoxicillin, cephalexin and nalidixic acid were mostly resistant. Conclusion: Empirical use of amoxicillin or cephalexin is usually not useful and routine use of anaerobic culture is not necessary.

Altitude Effect on the Properties of Honeys from the Region of Jijel (Algeria)

1. Alderman, D.J., Smith, P. (2001). Development of draft protocols of standard reference methods for antimicrobial agent susceptibility testing of bacteria associated with fish diseases. Aquaculture, 196(3-4), SI, 211–243. CrossRef Google Scholar

Oral Antimicrobial Agents for Urinary Tract Infections Due to Enterobacteriales Species

Background Urinary tract infections (UTIs) due to Enterobacteriales continue to pose a challenge because of increasing resistance rate to antimicrobial agents. The aim of this study was to evaluate in vitro susceptibility of oral antimicrobial agents against urinary isolates of Enterobacteriales species in patients with suspected UTIs at Hamilton Health Sciences hospitals in 2016. Methods Positive urine cultures for Enterobacteriales species in all patients 18 years or older with diagnosis of UTIs from 2 acute care hospitals in 2016 were included. Susceptibility rates were calculated for first- and second-line oral antimicrobial agents commonly used to treat UTIs. Results A total of 2773 urinary isolates of Enterobacteriales species were included in the analysis. The rates of susceptibility to nitrofurantoin were 96.3% (1925/1999) and 46.9% (188/401), respectively, for Escherichia coli and Klebsiella pneumoniae. The rates of susceptibility to trimethoprim-sulfamethoxazole and ciprofloxacin were 73.9% (1478/1999) and 84% (337/401), and 72.3% (1446/1999) and 86.3% (346/401), respectively, for E. coli and K. pneumoniae. The rate of E. coli susceptibility to oral cephalosporins was approximately 83%. The proportions of Enterobacteriales isolates that produced extended-spectrum β-lactamases (ESBLs) for E. coli and K. pneumoniae were 11.6% (231/1999) and 11.2% (45/401), respectively. The rates of ESBLs E. coli susceptibility to nitrofurantoin, trimethoprim-sulfamethoxazole, and ciprofloxacin were 91.3% (211/231), 30.3% (70/231), and 16% (37/231), respectively. Conclusions Oral antimicrobial agents have a limited role as empiric treatment of UTIs due to antibiotic-resistant Enterobacteriales species, with the exception of nitrofurantoin for E. coli including ESBL-producing strains. Oral cephalosporins were the second most susceptible agents to E. coli.

Detection of Antibiotic Resistance and Classical Enterotoxin Genes in Coagulase -negative Staphylococci Isolated from Poultry in Poland.

IntroductionThe study sought to characterise antimicrobial resistance among coagulase-negative Staphylococcus (CNS) species recovered from broiler chickens and turkeys in Poland including the presence of 12 antimicrobial resistance genes and five classical genes of staphylococcal enterotoxins.Material and MethodsA panel of 11 antimicrobial disks evaluated the phenotypic sensitivity of the tested strains to antibiotics. Five multiplex PCR assays were performed using primer pairs for specific detection of antibiotic resistance genes and staphylococcal enterotoxin A to E genes.ResultsSelected antimicrobial agent susceptibility testing revealed 100% of such in in vitro conditions to cefoxitin among strains of Staphylococcus sciuri and S. chromogenes. The blaZ (for ß-lactam) and mecA (for methicillin resistance) genes were in 58.3% and 27.5% of strains, respectively. Among genes resistant to tetracyclines, tetK was most frequent. Fewer (CNS) strains showed genes resistant to macrolides, lincosamides, and florfenicol/chloramphenicol. Multiplex PCR for classical enterotoxins (A-E) detected the see gene in two S. hominis strains, while the seb gene producing enterotoxin B was found in one strain of S. epidermidis.ConclusionCNS strains of Staphylococcus isolated from poultry were either phenotypically or genotypically multidrug resistant. Testing for the presence of the five classical enterotoxin genes showed that CNS strains, as in the case of S. aureus strains, can be a source of food intoxications.

Antimicrobial Agent Susceptibility and Typing of Staphylococcal Isolates from Subclinical Mastitis in Ewes.

Objective was to study susceptibility to antimicrobial agents of 142 staphylococcal isolates from subclinical mastitis in ewes. In total, 41.5% of these were resistant and 5.6% multidrug resistant. More coagulase-negative staphylococci (47.0%) were resistant than Staphylococcus aureus (18.5%) isolates. Resistance was greater to penicillin (22.5%), tetracycline, or ampicillin (18.3%). More biofilm-forming (20.6%) isolates were resistant to tetracycline than nonbiofilm-forming (0.0%) ones. Presence of tetK was associated with presence of icaA in the same strains. Further, 76.6% of resistant isolates versus 57.7% of susceptible ones were recovered immediately postpartum and 23.4% of resistant isolates versus 9.9% of susceptible ones were recovered in farms that practiced routine administration of antimicrobial agents at the end of a lactation period. Most S. aureus (59.3%) were classified in ST133 and most Staphylococcus epidermidis were classified in ST100, ST142, or ST152 (19.0% each). There was no association of sequence types with resistance. Whole genome sequencing showed that, in a Staphylococcus lentus strain, the ermB gene was part of transposon Tn917 integrated into the chromosome; also, a small plasmid was observed in an ermC-carrying Staphylococcus hominis strain and, finally, in an S. aureus and an S. epidermidis strains, small tetK-carrying plasmids (pSau-2716Lar, pSau-3893Lar) of 4.439 kb were found.

Staphylococcus aureus at an Indian tertiary hospital: Antimicrobial susceptibility and minimum inhibitory concentration (MIC) creep of antimicrobial agents.

Staphylococcus aureus causes a variety of symptoms and diseases and has been associated with high morbidity and mortality. A global population drift in clinical S. aureus isolates towards reduced antimicrobial susceptibility is being reported. In this study, the antimicrobial susceptibility profile and minimum inhibitory concentration (MIC) creep of vancomycin, linezolid, teicoplanin and rifampicin against clinical S. aureus isolates at an Indian tertiary centre from January 2012 to December 2016 were investigated. All consecutive, non-duplicate S. aureus isolates (n=1466) recovered from hospitalised patients identified by VITEK®2 were included in the study. Clinical isolates were tested against 20 antibiotics and were evaluated according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Statistical significance of the MIC creeps of four antimicrobials (vancomycin, linezolid, teicoplanin and rifampicin) was ascertained. S. aureus isolates recovered from all clinical samples demonstrated high resistance to ampicillin, ciprofloxacin and penicillin (75-100%) and low resistance to amikacin, linezolid, netilmicin, nitrofurantoin, teicoplanin and vancomycin (0-13%). The MIC90 values (MIC required to inhibit 90% of the isolates) for vancomycin, linezolid and rifampicin decreased, whereas the MIC90 for teicoplanin increased. The change in the geometric mean MIC of rifampicin was found to be statistically significant. A statistically significant and progressive MIC creep was observed for teicoplanin and rifampicin. Despite remaining susceptible, S. aureus is not inert to antibiotic pressure. Implementation of preventive measures in healthcare settings is required worldwide to combat the increasing number of infections by this pathogen.

Analysis of pathogen spectrum and antimicrobial resistance of clinical common organisms from twelve teaching hospitals in 2016

Objective To investigate the spectrum and antimicrobial resistance of major pathogens causing nosocomial infections in China, 2016. Methods Non-duplicated nosocomial cases as well as pathogens causing bloodstream infections (BSI), hospital-acquired pneumonia (HAP) and intra-abdominal infections (IAI) from 12 teaching hospitals across China were collected. The minimum inhibitory concentrations (MICs) of important clinical common strains were determined by agar dilution method or broth microdilution method. The CLSI M100-S27 criteria was used for interpretation. Data were analyzed by using WHONET-5.6 software. Results A total of 2 060 cases were collected, including 894 cases from BSI, 630 cases from HAP and 536 cases from IAI. The MICs of 1 896 important clinical common strains were determined. Escherichia coli and Klebsiella pneumoniae were the most prevalent pathogens causing BSI and IAI, while Acinetobacter baumanii and Pseudomonas aeruginosa were dominated in HAP. All Staphylococcus aureus were susceptible to tigecycline, linezolid, daptomycin and glycopeptides. Methicillin-resistant S. aureus accounted for 44.4% (75/169) of all the S. aureus. The rate of methicillin-resistant coagulase-negative staphylococci was 80.9% (72/89). No Enterococcus strains were found resistant to tigecycline, linezolid or daptomycin. Vacomycin resistant enterococcus was found in Enterococcus faecium, accounting for 1.8% (2/111) of all E. faecium strains. Tigecycline, meropenem, amikacin, imipenem, and polymyxin B exhibited high potency against Enterobacteriaceae and the susceptibility rates were 96.6% (865/895), 94.3% (859/911), 94.2% (858/911), 94.1% (857/911), and 91.6% (820/895), respectively. The prevalence of extended-spectrum β-lactamase was 58.4% (263/450) in E. coli and 28.6% (84/294) in K. pneumonia. The rate of carbapenem resistant K. pneumonia and E. coli was 15.3% (45/294) and 1.8% (8/450), respectively. The percentage of polymyxin B resistant K. pneumonia and E. coli was 4.1% (12/294) and 4.4% (20/450), respectively. The rate of tigecycline resistant K. pneumonia and E. coli was 2.4% (7/294) and 0.2% (1/450), respectively. A. baumanii showed low susceptibility to the antimicrobial agents except tigecycline (91.4%, 235/257) and polymyxin B (100%, 257/257). The rate of carbapenem resistant A. baumanii was 80.5% (207/257). The rate of carbapenem resistant P. aeruginosa was 31.7% (59/186). Polymyxin B and amikacin demonstrated high antibacterial activity against P. aeruginosa with susceptility rate of 100% (186/186) and 90.9% (169/186), respectively. Conclusions Nosocomial pathogens showed high susceptibilities against tigecycline and polymyxin B. Antimicrobial resistance in A. baumannii is a serious problem. The prevalence of carbapenem-resistant Enterobacteriaceae and polymyxin B resistant Enterobacteriaceae has increased, which should be monitored continuously in China.(Chin J Lab Med, 2018, 41: 651-657) Key words: Hospital infections; Drug resistance; Microbial sensitivity tests

Cell surface physiology and outer cell envelope impermeability for hydrophobic substances in Burkholderia multivorans.

The purpose of the present study was to obtain a better understanding of the relationship between cell surface physiology and outer cellular envelope permeability for hydrophobic substances in mucoid and non-mucoid B. multivorans strains, as well as in two capsule-deficient derivatives of a mucoid parental strain. Cell surface hydrophobicity properties were determined using the hydrocarbon adherence method, while outer cell envelope accessibility and permeability for non-polar compounds were measured using hydrophobic antimicrobial agent susceptibility and fluorescent probe assays. Extracellular polysaccharide (EPS) production was assessed by cultivating strains of disparate origin on yeast extract agar (YEA) containing different sugars, while the resultant colonial and cellular morphological parameters were assessed macro- and microscopically, respectively.Results/Key findings. The cell surfaces of all the strains were hydrophilic, impermeable to mechanistically disparate hydrophobic antibacterial agents and inaccessible to the hydrophobic probe N-phenyl-1-napthylamine, regardless of EPS phenotype. Supplementation of basal YEA with eight different sugars enhanced macroscopic EPS expression for all but one non-mucoid strain, with mannose potentiating the greatest effect. Despite acquisition of the mucoid phenotype, non-mucoid strains remained non-capsulated and capsulation of a hyper-mucoid strain and its two non-mucoid derivative strains was unaffected, as judged by microscopic observation. These data support the conclusion that EPS expression and the consistent mucoid phenotype are not necessarily associated with the ability of the outer cell surface to associate with non-polar substances or cellular capsulation.

PCR-RFLP-Based Detection of Mutations in the Chromosomal Fluoroquinolone Targets g yr A and p ar C Genes of Acinetobacter b aumanii Clinical Isolates from a Tertiary Hospital in Cairo, Egypt

Background and Aim: Acinetobacter baumannii is one of the most antimicrobial resistant nosocomial pathogens encountered clinically worldwide. The emergence of fluoroquinolone resistance among A. baumannii isolates is currently of concern. This study aimed to investigate the antimicrobial susceptibility patterns among 49 clinical isolates of A baumannii collected from a tertiary care hospital in Egypt. These isolates were analysed for the mechanism of fluoroquinolone resistance based on the presence of mutations in the quinolone resistance-determining regions (QRDRs) of the chromosomal quinolone resistance determinants gyrA and parC genes. Methods: A. baumannii isolates were identified using conventional biochemical testing, VITEK 2 automated system and polymerase chain reaction (PCR) assay targeting the intrinsic blaOXA-51-like gene of A. baumannii species. Antimicrobial susceptibility to different antimicrobial agents was tested using agar disk diffusion method and the minimum inhibitory concentration (MIC) of ciprofloxacin was determined using E-test (bioMerieux, France) on Mueller-Hinton agar medium following the Clinical and Laboratory Standards Institute guidelines. The QRDRs of the gyrA and parC genes in A. baumannii isolates were amplified by PCR using specific primers. Mutations in theses QRDRs were detected by HinfI restriction fragment length polymorphism (RFLP) of PCR products and sequencing. Results: The blaOXA-51-like gene was detected in all isolates confirming identification as A. baumannii. Antimicrobial susceptibility study showed that all isolates (100 %) were MDR. They were 100 % resistant to the tested fluoroquinolones, ciprofloxacin and levofloxacin. The MIC of ciprofloxacin ranged from 4 to ≥ 32 μg/mL. All A. baumannii isolates (100 %) were found to harbour gyrA and parC genes. HinfI restriction analysis showed a detectable mutation in QRDRs at position Ser-83 of gyrA gene and Ser-80 of parC gene. There was single mutation in either gyrA or parC in 11 isolates showed ciprofloxacin MIC of < 32 μg/mL, while 38 isolates with MIC of ≥ 32 μg/mL had double mutations in QRDRs of both genes. Conclusions: Resistance of A. baumannii isolates to fluoroquinolones in Egypt is alarming as all MDR A. baumannii isolates in the current study were mostly highly resistant to ciprofloxacin with MIC ≥ 32 μg/mL, limiting the remaining therapeutic options and a public health policy on appropriate prescribing and thus the rational use of antimicrobial agents is required. Double mutation with substitutions at positions Ser-83 and Ser-80 of gyrA and parC genes, respectively, could lead to high‐level ciprofloxacin resistant phenotype than a single mutation in one of them. Further extensive studies including a larger number of isolates from different geographic areas in Egypt and investigating other fluoroquinolone resistance mechanisms are warranted.

Susceptibility of respiratory isolates of Streptococcus pneumoniae isolated from children hospitalized in the Clinical center Nis

Streptococcus pneumoniae is one of the most common causes of respiratory infections. The aim was to study the susceptibility to antimicrobial agents of respiratory isolates ofStreptococcus pneumoniae obtained from hospitalized children. A total of 190 respiratory pneumococcal isolates obtained from children aged from 0 to 14 years were isolated and identified by using standard microbiological methods. Susceptibility to oxacillin, erythromycin, clindamycin, tetracycline, cotrimoxazole, ofloxacin and rifampicin was tested by disc diffusion method. Minimal inhibitory concentrations for amoxicillin and ceftriaxone were determined by means of E test. The macrolide-resistant phenotype was detected by double disc diffusion test. All tested isolates were susceptible to amoxicillin and ceftriaxone. The minimal amoxicillin concentration inhibiting the growth of 50% of isolates and of 90% of isolates was 0.50 microg/ml and 1.0 microg/ml, respectively and the minimal ceftriaxone concentration inhibiting the growth of 50% of isolates and of 90% of isolates was 0.25 microg/ml and 0.50 microg/ml, respectively. Susceptibility to erythromycin and clindamycin was observed in 21.6% and 29.47% of isolates, respectively. The resistence to macrolides-M phenotype was detected in 10.07% of isolates and constitutive macrolide-lincosamide-streptogramin phenotype (constitutive MLS phenotype) was found in 89.93% of isolates. All tested isolates were susceptible to ofloxacin and rifampicin. Amoxicillin could be the therapy of choice in pediatric practice. The macrolides should not be recommended for the empirical therapy of pneumococcal respiratory tract infection in our local area.

승용 씨암말의 생식기 유래 세균의 분포 및 항생제 감수성 양상

Abstract This study was carried out to investigate the genital tract bacterial flora of riding mare in Jangsu stud farm during March to September, 2014. The specimens were collected from vaginal and uterus using a swab from 104 riding mares. Colonies were selected on blood and MacConkey agar plates, and identi-fied as standard biochemical properties and Maldi-Tof MS. From this study, we isolated 148 strains includ-ing Escherichia ( E. ) coli (14.19%), Streptococcus ( S. ) equi subsp. zooepidemicus (2.7%), Streptococcus ( S. ) dysgalactiae subsp. equisimilis (2.03%), Klebsiella ( K. ) pneumonia (1.35%) and other strains from riding mares. In antimicrobial agents susceptibility test, it showed a high sensibility to the antibiotics of the most. E. coli and S. zooepidemicus were visible to have a high sensibility to almost antibiotics used in this study. However, K. pnemoniae showed a high antibiotic resistance patterns. These results may provide the basic information to establish strategies for the treatment and prevention of reproductive dis-eases in riding mares in Korea.

English

The WHO in 1977 provided the proper definition of drug utilization. It has been defined as the marketing, distribution, prescription and use of drugs in society with special emphasis on the resulting medical and social consequences. Antibiotics are a commonly prescribed group of drugs and the problem of their overuse is a global phenomenon. Studies from India have shown that the use of antimicrobial agents varies from 24 to 67 percent. Primary Health care is integral part of any country's health care delivery system, its importance is vital when considered for the developing countries. AIMS: To evaluate prescription pattern and criteria for selection of antimicrobial agents (AMAs) in Primary Health Centre and to analyze rationality among the prescriptions. To monitor Adverse Drug Reactions (ADRs) encountered during the course of the study. METHODS AND MATERIALS: This prospective, observational and analytical study was done to assess the pattern of antimicrobial agent (AMA) use in patients attending Mahagaon Primary Health Centre (PHC) in Gulbarga district, Karnataka. The reason for AMA use, criteria for selection, AMA susceptibility, efficacy and tolerability of AMAs and treatment outcome of AMAs were evaluated. Patients receiving AMA therapy of either gender, of any age, seeking out-patient treatment from Mahagaon PHC, were included in this study. The study was carried out between March, 2014 and May, 2014 (3 months). Three hundred (300) consecutive patients receiving AMAs, were included in the study. RESULTS AND CONCLUSION: The results indicate that a satisfactory standard has been maintained in several areas in the studied PHC. Even more judicious use of antibiotics is recommended and specific therapy should be promoted over empirical therapy.

Evaluation of Selected Toxigenic Genes and Antimicrobial Agent Susceptibility in Staphylococcus Spp Isolated from Foods Purchased from North Dakota Grocery Stores

Evaluation of Selected Toxigenic Genes and Antimicrobial Agent Susceptibility in Staphylococcus Spp Isolated from Foods Purchased from North Dakota Grocery Stores The present study was done to assess the incidence of five superantigenic toxin genes and toxin expression; and the antimicrobial susceptibility in food-derived coagulase-negative-Staphyloccus (CNS). Sixty-two (16.1%) Staphylococcus isolates from 385 food samples were tested by polymerase chain reaction (PCR) for five superantigenic toxin genes including four classical enterotoxins (sea, seb, sec, sed, and see), and toxic shock syndrome toxin-1 (tsst-1).