High level of aminoglycoside resistance among Enterococcus faecalis and Enterococcus faecium strains

Enterococcus sp. strains are believed as important reason of serious nosocomial infections currently. These infections are cured by using combination of beta-lactams and aminoglycosides for their treatment. Enterococcus sp. resistant to high-level doses of aminoglycosides, beta-lactams and vancomycin are responsible for therapeutic failure. The aim of our study was to evaluate the incidence of isolation and susceptibility to antibiotics of HLAR Enterococcus sp. strains isolated between 2007 and 2010 from the patients of University Hospital No. 1 of dr A. Jurasz Collegium Medicum of L. Rydygier in Bydgoszcz Nicolaus Copernicus University in Toruń. Amongst 6137 Enterococcus sp. strains 1124 (18,3%) presented HLAR phenotype; 53,1% of them was identified as E. faecalis and 46,9% as E. faecium. The highest percentage of all examined strains was isolated from the patients of different surgery clinics, Intensive Care Units, and Pediatrics, Hematology and Oncology Clinic. HLAR and HLSR phenotypes were noted in E. faecalis, for 45,7% and 27,5% strains, in E. faecium - 29,8% and 9,5%, respectively. HLGR phenotype was presented twice more often in E. faecium than E. faecalis. Highest percentages of E. faecium resistant to glycopeptides and rifampicin were observed when compared with E. faecalis. The highest percentages of strains intermediate, resistant to vancomycin and resistant to glycopeptides were noted for E. faecium strains with phenotypes HLAR, HLGR and HLSR.     

The drug susceptibility of penicillin-resistant Streptococcus pneumoniae

The aim of our study was to evaluate a frequency of isolation and susceptibility to antibiotics of Streptococcus pneumoniae penicillin resistant among 154 strains S. pneumoniae isolated between 2003 and 2006 in University Hospital of Dr. A. Jurasza in Bydgoszcz. Antimicrobial susceptibility was assessed by disc-diffusion method according to the guidelines of Clinical and laboratory Standards Institute and The national Reference Centre for Antimicrobial Susceptibility. Minimal inhibitory concentrations for penicillin and cefotaxime were assessed by E-test method. Study shows increasing isolation of SPPR strains from 8,2% in 2003 to 32,0% in 2006. Strains were mostly isolated from patients ofNeurosurgery and Neurotraumatology Clinic and Rehabilitation Clinic. SPPR strains were mainly isolated from respiratory tract. Over 68% of SPPR showed intermediate resistance to penicillin and 73,3% of strains were susceptible to cefotaxime. Between 2003 and 2006 increased percentage of resistance strains to erythromycin, tetracycline and sulphometoxasol.     

Antimicrobial sensitivity of Escherichia coli strains with K1 antigen isolated from pregnant women and newborns

The aim of this study was comparison of the susceptibility to antibiotics of E. coli strains with K1 antigen (E. coli K1+) and non-K1 E. coli strains (E. coli K1-). This study included 67 of E. coli K1+ and 67 of E. coli K1- strains isolated in the time period from June to September of 2008 from pregnant women and newborns hospitalized at dr. J. Biziel University Hospital number 2 L. Rydygier Collegium Medicum in Bydgoszcz Nicolaus Copernicus University in Toruń. Antimicrobial susceptibility of E. coli strains was tested by the disc-diffusion method, on the Mueller Hinton 2 Agar (Becton Dickinson). It was found that 64,2% of E. coli K1+ strains and 53,7% of E. coli K1-strains were susceptible to all tested antibiotics and chemioterapeutics. E. coli K1- strains were more often than E. coli K1+ nonsusceptible to at least one antimicrobial agent. The obtained results indicate that E. coli K1+ strains significant differed in the susceptibility to ampicillin/sulbactam (85,1% versus 95,5%) (p=0,041), cephalothin (70,1% versus 85,1%) (p=0,038) and tetracycline (91,0% versus 74,6%) (p=0,012) from E. coli K1-strains. All tested E. coli K1+ and K1-strains were sensitive to piperacillin/tazobactam, cefoperazone/sulbactam, cefotaxime, ceftazidime, cefepime, imipenem, amikacin, netilmicin and tigecycline. There weren't the ESBL-producing strains among tested E. coli K1+ and K1- rods.     

Antibiotic sensitivity of beta-hemolytic streptococci isolated from throat swabs and purulent material

The aim of this study was to evaluate the prevalence and susceptibility of beta-hemolytic streptococci isolated from throat swabs (142--29.9%) and purulent material (333--70.1%) taken from patients treated at University Hospital dr. A. Jurasz in Bydgoszcz Collegium Medicum. L. Rydygier in Bydgoszcz, Nicolaus Copernicus University in Torun in 2005-2009. Of the 475 tested strains, 156 (32.8%) were identified as S. pyogenes. This species accounted for 38.8% of strains isolated from purulent material and 19.0% of swabs from the throat. Among the strains isolated from throat swabs of 62 (43.7%) were identified as Streptococcus group C. Only 5.1% strains were identified as Streptococcus group F. All strains of beta-hemolytic streptococci were susceptible to ampicillin or penicillin, fluoroquinolones, vancomycin and linezolid. Erythromycin-susceptible strains was 83.8%, and 89.1% for clindamycin. A total of 51.3% of erythromycin resistance strains had the cMLS(B) phenotype (63.3% for strains from throat swabs and 46.3% of the purulent materials). Sensitivity to tetracycline was characterized by 51.2% of strains of beta-hemolytic streptococci. The percentage of strains susceptible to this antibiotic among isolates from throat swabs was 63.1%, and purulent material--48.0%. The lowest percentage of strains susceptible to tetracycline (14.1%) were found among S. agalactiae and Streptococcus group G (33.6%) strains. During the study time, saw an increase in the percentage of strains susceptible to tetracycline and erythromycin.     

Prevalence of multidrug-resistant Proteus spp. strains in clinical specimens and their susceptibility to antibiotics

Proteus sp. are opportunistic microorganisms which cause urinary tract and wounds infections, bacteriaemia and sepsis. The aim of this study was analysis of prevalence of multidrug-resistant Proteus sp. strains in clinical specimens and evaluation of their susceptibility to selected antibiotics. The study was carried out of 1499 Proteus sp. strains were isolated in 2000-2003 from patients of departments and dispensaries of the University Hospital CM in Bydgoszcz UMK in Torun. The strains were identified on the basis of appearance of bacterial colonies on bloody and McConkey's agars, movement ability, indole and urease production and in questionable cases biochemical profile in ID GN or ID E (bio-Mérieux) tests was also included. Antibiotic susceptibility was tested by disk diffusion method. Isolated strains were regarded as multidrug-resistant when they were resistant to three kinds of antibiotics at least. Received Proteus sp. the most frequently belonged to P. mirabilis species (92.3%). Most of these bacteria were isolated from urine from patients of Rehabilitation Clinic. All of multidrug-resistant strains were resistant to penicillins and cephalosporins, 98.9% to co-trimoxazole, 77.7% to quinolones, 63.8% to tetracyclines, 38.5% to aminoglycosides, 19.3% to monobactams and 3.4% to carbapenems. Almost 25% multidrug-resistant Proteus sp. produced ESBL.     

Occurrence of p-fimbriae in enteropathogenic E coli (EPEC) and in E. coli strains isolated from patients with urinary tract infections]

The aim of this study was to gain knowledge of prevalence of P+ clones among EPEC strains isolated from children with diarrhoea and E. coli strains isolated from urine. Three hundred eighty four E. coli strains isolated from children with diarrhoea were tested. They belonged to 11 serotypes (018, 025, 026, 044, 055, 0111, 0114, 0119, 0124, 0125, and 0128). Nine hundred thirty colonies of E. coli from Mac Conkey's agar plated quantitatively with urine samples of 178 individuals suffering from urinary tract infections were also tested. All strains were assayed by mannose-resistant active haemagglutination test (MRHA) and by slide agglutination using self prepared latex reagent for detection of P fimbriae. Out of 384 E. coli strains tested 122 (31.8%) showed presence of adhesins detected by mannose-resistant active haemagglutination test (MRHA) and in 90 (23.3%) out of all tested strains the presence of P fimbriae was found. The highest percentage of P fimbriae prevalence was found in E. coli belonging to the following serotypes: 018 (in 68.9% strains), 025 (in 29.2% strains), and 0125 (in 25.0% strains). This type of fimbriae was also detected in serotypes 026 (9.1%), 044 (8.7%), 055 (5.6%), and 0119 (in 2 strains out of 5 isolated). Out of 933 colonies of E. coli, isolated from 178 urine samples, 434 (46.5%) colonies gave positive results in MRHA test, including 133 positive in latex test for P fimbriae. These studies showed that for MRHA adhesins, including P fimbriae, a parallel examination of higher number of E. coli was necessary.(ABSTRACT TRUNCATED AT 250 WORDS)     

Occurrence and drug-resistance of beta-hemolytic streptococci

The aim of this study was the analysis of drug-resistance and frequency appearance of beta-hemolytic streptococci strains which were isolated in 2003-2005 in the University Hospital at the L. Rydygier Collegium Medicum in Bydgoszcz University of Nicolaus Copernicus in Toruń. Among investigeted beta-hemolytic streptococci the most frequency isolated species was S. agalactiae. All isolates examined in our study were susceptible to penicillin, the higest rate of resistance was found for tetracycline. The rates of resistence to macrolide-lincosamide-streptogramin B (phenotyp MLS(B)) were as follows: S. agalactiae (18.7%), S. pyogenes (10.1%), group G streptococci (10.6%) and group C streptococci (8.0%). In our study we presented also a special case patient from which in investigeted period S. agalactiae was isolated twenty eight times. For ten chromosomal DNA isolated from this patient three different PFGE profiles were obtained.     

Influence of staphylococcin T on Enterococcus sp. growth

Bacteriocins are ribosomally synthesised, extracellular bacterial products. Generally, spectrum of inhibition is limited to the same or closely related species to bacteriocin producer. Staphylococcin T is produced by Staphylococcus cohnii strain. The present study concerns influence of StT to 267 Enterococcus sp. strains growth isolated between 2003 and 2006 in Department of Microbiology University Hospital of dr. A. Jurasz in Bydgoszcz. S. cohnii T antagonistic ability evaluated towards bacteries on Mueller-Hinton Agar (bio Mérieux) in aerobic conditions. After 24 and 48 hours tested enterococci suspensions were plated perpendiculary. Susceptibility to antibiotics was assessed by disc diffusion method according to the guideless of Clinical and Laboratory Standards Institute and National Reference Centre for Antimicrobial Susceptibility. Among Enterococcus sp. strains tested 7.1% were sensitive to StT. The highest percentage of sensitive enterococci isolated from wound swabs, urine, blood and pus. Enterococcus faecium strains dominated (63.2%) among enterococci sensitive to StT. Moderate inhibition degree on S. cohnii T bacteriocin action was observed in majority sensitive enterococci strains. Enterococcus sp. sensitive to StT strains were frequently multidrug resistant (68.4%). According to the study results and increasing resistance to antibiotics, StT could be an alternative agent used to treat infections caused by Enterococcus sp.     

Imipenem resistance in Gram-negative rods and its consumption between 1999 and 2005

Multidrug resistant Gram-negative rods are increasingly isolated from clinical specimens, especially from hospitalized patients. The aim of this study was to evaluate the prevalence of imipenem resistant strains of Gram-negative rods isolated in dr. A. Jurasz University Hospital in Bydgoszcz between 1999 and 2005 and imipenem consumption in this period. Out of 109614 isolated microorganisms, Gram-negative rods were 28,5%, 637 (2,0%) of strains were resistant to imipenem. These strains were isolated mostly from patients hospitalized in intensive care and rehabilitation clinics. Among imipenem-resistant strains Pseudomonas aeruginosa prevailed (88,9%). P. aeruginosa strains were sensitive to colistin, 45,5% of them to aztreonam and 44,0% to ceftazidime. The imipenem consumption in the appropriate years included in this study was: 805,00; 1201,25; 940,00; 1390,00; 1660,00; 1341,25; 1841,25 DDD respectively, and was strictly connected with increasing imipenem-resistant Gram-negative rods isolation.     

Evaluation of Staphylococcus aureus and Escherichia coli biofilm formation on the surface of polypropylene mesh

A serious complication of hernioplasty with the use of a biomaterial implant is deep surgical site infection (SSI) encompassing the implant. Among the most common etiological factors of deep SSI in patients after hernioplasty are Staphylococcus aureus and Escherichia coli strains, which may create a biofilm on the surface of synthetic implants. The aim of this study was assessment of biofilm formation by S. aureus and E. coli on the surface ofpolypropylene mesh. The study included 108 strains (62 S. aureus and 46 E. coli) from the collection of Department of Microbiology Collegium Medicum im. L. Rydygier in Bydgoszcz, Nicolaus Copernicus University in Torun (CM UMK). Evaluation of biofilm formation was performed using the method of reduction of 2,3,5-triphenyltetrazolium chloride (TTC) and a scanning electron microscope. In the group of S. aureus strains, 88.7% isolates formed biofilm very strongly, 1.6% strongly, and 9.7% poor. Among E. coli strains, 54.3% isolates were characterized by very strong biofilm formation, while 45.7% strong biofilm formation. Strains ofS. aureus strongly than E. coli form a biofilm on the surface of monofilament polypropylene mesh.     

Analysis of microorganisms isolated from febrile neutropenic children with neoplastic disease

The microbiological evaluation of the blood was carried out as a continued monitoring of the microorganism culture using the colourmetric system VITAL 200 (bio-Mérieux). There have been analysed 4660 bacteriological research results of the peripheral blood, blood from Broviac and from Broviac liquid of the children suffering from cancer treated in the years 1997-2000 in the Pediatric, Hematology and Oncology Clinique of the State Clinical Hospital in Bydgoszcz. There have been gained 1032 positive cultures from KZZ, KZB, PZB. There have been recognized 259 bacteremia and 22 fungemia by the children with fever in the neutropenia period. In the analysed four years in the blood dominated Gram-positive bacteria. Among Gram-positive bacteria there were mostly Staphylococcus spp. (42.5%), mostly CNS, fewer numerous were Streptococcus spp. (14.5%) and Corynebacterium spp. (5.9%). Among Gram-negative bacteria mostly were isolated Acinetobacter spp. (25.6%), Pseudomonas spp. (9.7%), E. coli (13.8%), Enterobacter spp. (13.9%), Klebsiella spp. (9.2%). There were observed few infections by strains resistant to many antibiotics, S. maltophilia, B. cepacia, E. faecium, S. haemolyticus. All strains Staphylococcus spp. were sensitive to vancomycin. There have not been found Enterococcus spp. resistant to glycopeptides. Most active against Gram-positive rods were carbapenems and aminoglycosides.     

PCR-RAPD typing of carbapenem-resistant Pseudomonas aeruginosa strains

P. aeruginosa rods are opportunistic pathogens responsible generally for nosocomial infections. Resistance to carbapenems, observed among them, is a serious threat due to ability to be transmitted between bacterial species. The aim of our study was to evaluate the usefulness of PCR-RAPD technique in typing of 16 carbapenem-resistant P. aeruginosa strains isolated in 2007 from different patients of University HospitalNo. 1 of dr A. Jurasz Collegium Medicum of L. Rydygier in Bydgoszcz Nicolaus Copernicus University in Toruń. Study shows increasing frequency of isolation that type of strains when compared to 2006. Percentage of carbapenem-resistant isolates raised from 12,4% in 2006 to 22.9% in 2007. The majority of examined strains were obtained from patients of the Intensive Care Units (25.0%) and were isolated from bronchoalveolar lavage (25.0%), urine (25.0%) and wound swabs (18.8%) samples. Examined P. aeruginosa strains demonstrated resistance to doripenem (81.3%) and piperacillin (75.0%) and susceptibility to colistin (100.0%), amikacin (81.3%), netilmicin and norfloxacin (75.0% each). Using PCR-RAPD amplification with 208 and 272 primers, 14 and 16 DNA patterns were obtained, respectively. Usefulness of PCR-RAPD in carbapenem-resistant P. aeruginosa strains typing was proved in case of strains presenting similar and/or different antimicrobials susceptibility patterns.     

老年大肠埃希菌血流感染患者的临床分析

为探讨老年大肠埃希菌血流感染患者的临床特点及药敏结果,回顾性分析徐州医科大学附属医院2013年1月-2016年12月340例大肠埃希菌血流感染老年患者的临床资料及药敏结果,采用SPSS软件进行分析。结果显示,患者均合并基础疾病(恶性肿瘤、高血压病、糖尿病、肺部感染等);感染途径主要为消化道(38.5%)、呼吸道(36.8%)和泌尿道(22.6%);检出产超广谱β-内酰胺酶(extended-spectrum β-lactamase,ESBL)大肠埃希菌96例(28.2%);ESBL阳性菌对氨苄西林、复方磺胺甲恶唑、环丙沙星、哌拉西林、第3代头孢、左氧氟沙星的耐药率均高;所有菌株均对碳青霉烯类敏感。结果提示,该院老年大肠埃希菌血流感染患者均合并基础疾病,常见感染途径是消化道、呼吸道和泌尿道,ESBL阳性大肠埃希菌除对碳青霉烯类抗菌药物敏感外,对多种抗菌药物耐药。     

Incidence of alginate-coding gene in carbapenem-resistant Pseudomonas aeruginosa strains

Pseudomonas aeruginosa rods are one of the most common isolated opportunistic nosocomial pathogens. Strains usually are capable to secret a capsule-like polysaccharide called alginate important for evasion of host defenses, especially during chronic pulmonary disease of patients with cystic fibrosis. Most genes for alginate biosynthesis and lysis are encoded by the operon. The aim of our study was to evaluate the incidence of algD sequence, generally use for alginate-coding gene detection, in 120 P. aeruginosa strains resistant to carbapenems. All isolates were obtained in the Department of Clinical Microbiology University Hospital no. 1 of dr A. Jurasz Collegium Medicum of L. Rydygier in Bydgoszcz Nicolaus Copernicus University in Toruń. Examined strains demonstrated resistance to carbenicillin (90,0%), ticarcillin (89,2%) and ticarcillin clavulanate (86,7%). All strains were susceptible to colistin. The majority of examined strains was susceptible to ceftazidime and cefepime (40,8% each) and norfloxacin (37,5%). Presence of algD gene - noted in 112 (93,3%) strains proves that not every strain is capable to produce alginate. It was also found out that differences in algD genes incidence in case of different clinical material that strains were isolated from were not statistically important.     

Comparison of disk-diffusion method and PCR for detection of methicillin resistance in Staphylococcus aureus strains

The aim of the study was to compare the disk-diffusion (oxacillin 1 microg, cefoxitin 30 microg) method and PCR for detection of methicillin-resistance in S. aureus. The investigation were carried out on 120 S. aureus strains isolated from clinical materials of patients hospitalized in the University Hospital at the L. Rydygier Collegium Medicum in Bydgoszcz, University of Nicolaus Copernicus in Toruń. Of the 120 S. aureus strains tested, 60 (50%) were mecA-positive by PCR. Consistency of results between oxacillin disk-difussion method and PCR amounted 92.5% and cefoxitin disk-diffusion method and PCR--98.3%. The oxacillin disk-difussion method falsely identified 3 (2.5%) strains as MSSA (sensitivity 95.0%) and 4 strains as MRSA (specificity 93.3%) in comparison with PCR. The cefoxitin disk-diffusion method falsely identified 2 (1.6%) strains as MSSA (sensitivity 96.7%) and there were no false resistant results (specificity 100%). Our results showed that in disk-diffusion tests, cefoxitin is a better than oxacillin for the identification of MRSA.     

320例腹泻患者病原菌分离及流行病学分析

目的了解广州市2009年至2010年肠道门诊就诊的细菌性腹泻患者病原谱的分布情况,为制定针对重点人群肠道传染病防治策略提供依据。方法收集2009年5月至2010年5月暨南大学附属第一医院腹泻患者的粪便标本,使用卡-布运送培养基,增菌培养后,采用生化反应和氧化酶试验进行菌株鉴定,并用梅里埃API生化板条进行验证,用病原菌诊断血清进行细菌分型。结果从320份粪便标本中分离到38株菌株,其中沙门菌15株,产毒大肠埃希菌12株,致病大肠埃希菌6株,志贺菌2株,出血性大肠埃希菌、霍乱弧菌、气单胞菌各1株。0—20岁年龄段高发,以1岁以内婴幼儿为主;7—10月为发病高峰期。结论来该院肠道门诊就诊的细菌性腹泻患者,其病原体以沙门菌为主,其次为产毒大肠埃希菌。因此．广州地区细菌件腹泻的预防．廊右针对件的面向雷占人群和重占病厢莴．     

Occurrence of Corynebacterium amycolatum strains in clinical specimens

C. amycolatum is poorly recognized and rarely described in the world literature. So, better recognizing and understanding biology of these bacteria may help effectively prevent infections caused by them. The subject within the study were 70 of C. amycolatum strains which were isolated from the clinical specimens of patients hospitalized at the State Clinical Hospital in Bydgoszcz. After initial identification of examined strains based on Gram staining results, colonial morphology, biochemical and enzymatic features included in API Coryne and API ZYM tests (bioMérieux), growth at 20 degrees C, Tween 80 requirement, DNA and tyrosine hydrolysis, occurrence in clinical specimens and origin of C. amycolatum strains were analyzed. The investigated strains were the most frequently isolated from wound swabs (61.5%), urine (14.3%), drain swabs (7.1%) and mainly (37.2%) came from patients treated at the departments of surgery.     

2010至2011年我院产ESBLs大肠埃希菌的耐药性分析

分析2010年1月至2011年12月牡丹江医学院附属红旗医院临床分离的大肠埃希菌的耐药性变化,为指导临床合理用药提供依据。2010至2011年临床各科室送检的全部标本(包括血、尿、便、痰、分泌物等),采用微生物分析仪进行分离鉴定及药物敏感性分析。2010和2011年产ESBLs大肠埃希菌检出率分别为23.8%5、7.4%,呈上升趋势。产ESBLs大肠埃希菌对大多数抗菌药物的耐药率明显高于非产ESBLs大肠埃希菌(P<0.05)。产ESBLs大肠埃希菌检出率越来越高,耐药率日益严重,给临床抗菌治疗带来很大困难,开展产ESBLs大肠埃希菌耐药性分析,指导临床合理应用抗生素,对控制大肠埃希菌对抗菌药物的耐药性增长有重大意义。     

Verotoxin-producing Escherichia coli (VTEC), enteropathogenic E. coli (EPEC) and necrotoxigenic E. coli (NTEC) isolated from healthy cattle in Spain

AIMS: To determine the prevalence and characteristics of verotoxigenic Escherichia coli (VTEC), enteropathogenic E. coli (EPEC) and necrotoxigenic E. coli (NTEC) in healthy cattle. METHODS AND RESULTS: Faecal samples from 412 healthy cattle were screened for the presence of VTEC, EPEC and NTEC. Four isolates from each sample were studied. VTEC, EPEC and NTEC were isolated in 8.7%, 8.2% and 9.9% of the animals, respectively. VTEC and NTEC were isolated more frequently from calves and heifers than from adults. Seventy (4.2%), 69 (4.2%) and 74 (4.5%) of the 1648 E. coli isolates were VTEC, EPEC and NTEC, respectively. Seventeen (24.3%) of the VTEC strains were eae-positive. Thirty-six (51.4%) of VTEC strains belonged to E. coli serogroups associated with haemorrhagic colitis and haemolytic uraemic syndrome in humans. The serogroups most prevalent among the EPEC strains were O10, O26, O71, O145 and O156. CONCLUSIONS: Healthy cattle are a reservoir of VTEC, EPEC and NTEC. SIGNIFICANCE AND IMPACT OF THE STUDY: Although most of the VTEC strains were eae-negative, a high percentage of VTEC strains belonged to serogroups associated with severe disease in humans.     

Antibiotic resistance and plasmid pattern of enterotoxigenic ST-a strains of Escherichia coli isolated in Puebla, México

Antibiotic susceptibilities of 22 strains of Escherichia coli isolated from children from 0 to 3 years old at the University Hospital of Puebla were determined. Almost all strains were resistant to ampicillin, tetracycline, streptomycin, and kanamycin. Gel electrophoresis of DNA from 10 clinical strains of E. coli revealed a heterogeneous plasmid population. Plasmid DNA, ranging in molecular mass from 1.8 to 120 megadaltons, was demonstrated in 10 strains. Moreover, the frequency of antibiotic transfer ranged from 1.6/10(8) to 2/10, and the simultaneous transfer of the gene encoding heat-stable enterotoxin was also determined. Six out of 10 strains tested were able to cotransfer ST-a as demonstrated by the suckling mouse test. It is possible that antibiotic selective pressure may increase the isolation of enterotoxigenic E. coli strains.