Antimicrobial susceptibility and characterization of Salmonella isolates from processed bison carcasses

Seventeen Salmonella enterica serovar Hadar isolates recovered from bison were found to possess a range of virulence genes and resistance to tetracycline, gentamicin, sulfamethoxazole, and streptomycin simultaneously. A 1-kb class 1 integron containing the aadA1 gene was identified in all isolates. Pulsed-field gel electrophoresis found that all isolates were closely related, indicating the possibility of cross-contamination during processing.     

Antimicrobial susceptibility of bacterial isolates from sea otters (Enhydra lutris)

Bacterial infections are an important cause of sea otter (Enhydra lutris) mortality, and some of these infections may originate from terrestrial and anthropogenic sources. Antimicrobials are an important therapeutic tool for management of bacterial infections in stranded sea otters and for prevention of infection following invasive procedures in free-ranging otters. In this study, susceptibility to commonly used antimicrobials was determined for 126 isolates of 15 bacterial species or groups from necropsied, live-stranded injured or sick, and apparently healthy wild sea otters examined between 1998 and 2005. These isolates included both gram-positive and gram-negative strains of primary pathogens, opportunistic pathogens, and environmental flora, including bacterial species with proven zoonotic potential. Minimal evidence of antimicrobial resistance and no strains with unusual or clinically significant multiple-drug resistance patterns were identified. Collectively, these findings will help optimize selection of appropriate antimicrobials for treatment of bacterial diseases in sea otters and other marine species.     

Antimicrobial susceptibility and genetic relatedness of bovine Stenotrophomonas maltophilia isolates from a mastitis outbreak

Aims: To evaluate the antimicrobial susceptibility and genetic relatedness of 11 Stenotrophomonas maltophilia isolates from an outbreak of bovine clinical mastitis in one herd and two isolates from two separate mastitis cases in two other herds. Methods and Results: Thirteen S. maltophilia isolates were obtained from milk samples from 11 cows from three dairy herds in Japan during 2008. We tested their susceptibility to 14 antimicrobials by broth microdilution and identified their genotypes by enterobacterial repetitive intergenic consensus 2 (ERIC2)‐PCR. Every cow had acute mild mastitis (slightly watery foremilk with flakes) without systemic symptoms and all resolved within 3–5 weeks of diagnosis. Eleven of the 13 isolates derived from nine cows in one herd over a 7‐month period exhibited a closely related ERIC2 type (A). The remaining two isolates derived from two cows from two other herds exhibited two distinct ERIC2 types (B and C). Most of the 13 isolates exhibited susceptibility to trimethoprim‐sulfamethoxazole, chloramphenicol, minocycline and levofloxacin; however, they were resistant to four β‐lactams, kanamycin, gentamicin and oxytetracycline. They were intermediate to enrofloxacin. Conclusions: Eleven closely related S. maltophilia isolates were involved in a herd outbreak of mastitis to some extent. Bovine S. maltophilia isolates exhibited resistance to many classes of antimicrobials. Significance and impact of study: This is a rare report of a herd outbreak of bovine mastitis involving closely related S. maltophilia isolates.     

临床分离奇异变形杆菌耐药性及产ESBLs菌株的流行现状

【摘 要】 目的 了解临床分离奇异变形杆菌的耐药性及产超广谱β-内酰胺酶(ESBLs)的流行情况,为临床治疗提供实验室依据。方法 收集临床分离的奇异变形杆菌共33株, 用琼脂稀释法检测其对14种抗菌药物的耐药性,并用超广谱β-内酰胺酶确证试验筛选出产ESBLs细菌。结果 33株奇异变形杆菌对亚胺培南耐药率为0、对头孢唑啉耐药率为100%,对哌拉西林、头孢呋辛、头孢他啶、头孢噻肟、头孢吡肟、氨曲南、阿米卡星、庆大霉素和氯霉素耐药率分别为12.1%、30.3%、24.2%、27.3%、18.2%、21.2%、12.1%、18.2%和48.5%,氟喹诺酮类抗菌药物耐药率较高,加替沙星、环丙沙星和左氧氟沙星耐药率分别为45.5％、39.4％和39.4％;产ESBLs菌株检出率为18.2%(6/33),除了头孢唑啉、哌拉西林、亚胺培南外,产ESBLs菌株的耐药率比非产ESBLs菌株都有不同程度地增加（P<0.01）。结论 临床分离奇异变形杆菌对亚胺培南均敏感,对头孢唑啉均耐药,对其他抗菌药物均有不同程度耐药,产ESBLs菌株的检出率高,且对抗菌药物的耐药程度比非产ESBLs菌株高。     

Antimicrobial susceptibility of microorganisms isolated from urine of pediatric ward patients

The study was an analysis of the frequency of urine bacterial isolation in hospitalized children as well as an evaluation of their susceptibility to antibiotics used in urinary tract infections (UTI). The analysis focused on microbiological urine tests carried out between January 2006 and December 2008. Altogether, 311 strains were obtained, of which E. coli (50.8%) and E. faecalis (13.5%) were the most frequently isolates. The highest percentage of Enterobacteriaceae were sensitive to ceftazidime (92%); to a lesser degree to amoxicillin/clavulanic acid (85%), to trimethoprim/sulfamethoxazole (84%), to nitrofurantoin (82%), to cefuroxime (81%), to cefalotin (66%) whereas only 24% were sensitive to ampicillin. ESBLs were produced by 8% of all Enterobacteriaceae strains. P. aeruginosa strains were totally sensitive to ceftazidime; over 90% - to piperacillin and aminoglycosides, and 77% to carbenicillin. Staphylococci manifested 100% sensitivity to nitrofurantoin. Only 20% of S. aureus were sensitive to trimethoprim/sulfamethoxazole and to trimethoprim; in the case of S. epidermidis: 83% and 67% respectively. No resistant strains were found among S. agalactiae and E. faecalis. E. faecium strains, in turn, were resistant to ampicillin and often to nitrofurantoin (64%), to vancomycin (VanB; 45%) and to high aminoglycoside concentrations (HLAR; 45%).     

Level of lactoferrin in serum and cerebrospinal fluid of patients with meningitis

Study showed 9-fold increase of concentration of lactoferrin (LF) in serum of patients with bacterial meningitis (BM) compared with normal concentration and 5-fold increase of LF concentration in patients with aseptic meningitis (AM). Level of LF in cerebrospinal fluid (CSF) of patients with BM and AM was 200-fold and 22-fold higher than in control group respectively. In 71% of patients with AM concentration of protein in CSF did not exceed minimal level observed in patients with BM. Level of LF in serum and CSF during treatment statistically significantly decreased. Concentration of LF (the latter is marker of neutrophilic granulocytes activation) can be used as a characteristic of acuteness and intensity of inflammatory process in central nervous system, whereas detection of LF in CSF--as additional criterion in differential diagnostics between bacterial and viral meningitis. Furthermore, repeated measurement of LF level can be useful for monitoring of disease course and assessment of effect of treatment.     

Circulating immune complexes in cerebrospinal fluid of patients with tuberculous meningitis.

Circulating immune complexes (ICs) were isolated from cerebrospinal fluids (CSFs) of patients with tuberculous meningitis (TBM), non-tuberculous neurological diseases by a polyethylene glycol (PEG) precipitation method. Mycobacterium tuberculosis antigen 5 was detected in CICs of 30% patients with TBM, by sandwich ELISA. CIC level decreases during antituberculosis chemotherapy and therefore its detection can provide a method to monitor the therapeutic schedule in patients with TBM.     

Antimicrobial susceptibility profiles associated with bacterial meningitis among children: a referral hospital-based study in Iran

Bacterial meningitis continues to be associated with high morbidity and mortality rate worldwide, especially in the pediatric age group. This study was performed to identify the microbial etiologies of meningitis among 31 children, who were admitted in the Emergency Ward of a referral pediatric hospital in Iran. Culture identification showed that Streptococcus pneumoniae (12 subjects), Haemophilus influenzae (11 subjects) were the most common bacteria, followed by Escherichia coli (7 cases) and Neisseria meningitidis (only one case). Antibiotic susceptibility tests revealed that vancomycin had the best effect on S. pneumoniae in comparison with other antibiotics, whereas H. influenzae and E. coli were more susceptible to ceftriaxone, ceftazidime, and ceftizoxime than other antibiotics. In conclusion, despite the advances in antibiotic therapy and vaccine development, bacterial meningitis still is a health problem. S. pneumoniae, H. influenzae, and N. meningitidis are the main sources of bacterial meningitis, but other organisms such as E. coli should also be suspected, when a case is admitted to a referral pediatric hospital.     

牙周炎患者菌斑细菌的药敏分析

目的:了解牙周炎患者龈下菌斑细菌对于口腔常用抗菌药物的敏感性.方法:从慢性牙周炎患者龈下菌斑中分离培养牙周可疑致病菌,测定6种口腔常用抗菌药物对其的最低抑菌浓度,分析以上致病菌对这几类抗菌药物的敏感性.结果:共从50名慢性牙周炎患者牙周袋中分离培养72株革兰阴性厌氧菌进行药物敏感试验.全部实验菌株都对阿莫西林/克拉维酸敏感.对甲硝唑、替硝唑、奥硝唑未见耐药株产生.结论:对于慢性牙周炎患者龈下菌斑中分离的厌氧菌,阿莫西林/克拉维酸和硝基咪唑类药物甲硝唑、替硝唑和奥硝唑的抑菌作用强.     

成人化脓性脑膜炎患者脑脊液变化

分析成人化脓性脑膜炎患者脑脊液细胞、病原菌等的变化及其关系, 为该病的有效诊断、病情监测和针对性治疗提供参考。

对我院32例成人化脓性脑膜炎患者用药前后不同时期的脑脊液分别进行常规、生化与细胞学检测, 对检测结果进行统计分析。

与恢复期比较, 患者急性期时脑压、脑脊液白细胞总数与乳酸脱氢酶水平显著升高(均P < 0.05)。32例患者中, 15例脑脊液细菌培养呈阳性。典型菌与非典型菌感染者急性期脑脊液白细胞总数、小淋巴细胞、单核吞噬细胞和嗜中性粒细胞比例差异均有统计学意义(均P < 0.05)。

成人化脓性脑膜炎患者脑脊液变化显著, 脑脊液细胞学变化与感染类型相关, 可为个性化诊疗提供参考。

     

Antimicrobial susceptibility of microflora from ovine cheese

Strains identified in ovine cheese and bryndza by matrix-assisted laser desorption/ionization time-of-flight analysis belonged to ten species of non-enterococcal lactic acid bacteria and included Lactobacillus casei/Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus helveticus, Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus brevis, Lactococcus lactis, Pediococcus pentosaceus and Pediococcus acidilactici. The susceptibility toward antibiotics was determined in lactobacilli, lactococci and pediococci and also in Escherichia coli for comparison. Analysis of L. fermentum and pediococci revealed the presence of non-wild-type epidemiological cut-offs in streptomycin, clindamycin or gentamicin. E. coli were resistant to ampicillin, tetracycline, enrofloxacin and florfenicol. No extended spectrum β-lactamases were detected.     

Biofilm formation and antifungal susceptibility of Trichosporon asahii isolates from Mexican patients

Background

Trichosporon asahii is a yeast-like fungus that has recently gained importance as a cause of opportunistic systemic infections. The pathogenicity and virulence factors of T. asahii remain largely unknown. Because of the association between invasive infections and the use of catheters and related devices, the ability of the microorganism to adhere and form biofilms may play an important role in the pathogenicity during a trichosporonosis.

Distribution and antifungal susceptibility of yeasts isolates from intensive care unit patients

Yeasts frequently colonize non-sterile sites in the body. The aim of the study was to determine distribution in clinical samples and antifungal susceptibility to five antifungals. From January 2013 through June 2015, 800 isolates were obtained from intensive care unit patients. Candida albicans (58.9%), Candida glabrata (20.4%), Candida krusei (8.6%), and Candida parapsilosis (3.6%) were the leading species. Majority of the C. albicans isolates were susceptible to the fluconazole. Elevated voriconazole minimal inhibitory concentrations (MICs) were observed in isolates exhibiting high fluconazole MICs, most frequently in C. glabrata. Isolates with echinocandins MICs suggesting reduced susceptibility were only sporadic cases with the exception of Trichosporon spp. The amphotericin B MICs were slightly higher for some C. krusei.     

Antimicrobial susceptibility of Clostridium difficile isolated from neonatal pigs with enteritis

The minimum inhibitory concentration (MIC) of eight antimicrobial agents was determined by the agar dilution method for 80 isolates of Clostridium difficile from neonatal pigs with enteritis. MICs(50) for erythromycin, tilmicosin, and tylosin were relatively low (0.25-0.50 microg/mL), but MICs(90) (64 or > or =256 microg/mL) suggest in vivo resistance of a proportion of isolates. Susceptibility to tetracycline varied widely, with MIC(50) and MIC(90) of 8 and 32 microg/mL, respectively. The MICs(90) for tiamulin (8 microg/mL) and virginiamycin (16 microg/mL) suggest moderate susceptibility. Bacitracin and ceftiofur (MICs(90) > or =256 microg/mL) have little activity against C. difficile. Tiamulin and virginiamycin may decrease fecal shedding of C. difficile by sows, and erythromycin, tetracycline, and tylosin may be useful for treatment of infected piglets.     

Antimicrobial use and susceptibility rates in isolates from intensive care unit and other nosocomial inpatient and outpatient areas

Our objective was to evaluate the relation between antimicrobial use and susceptibility in the intensive care unit (ICU) and non-ICU inpatient areas in the Bolzano regional hospital. For the isolates of S. aureus, coagulase negative staphylococci, Enterococcus sp., P. aeruginosa and E. coli we found a pattern of significant stepwise decrease in the frequency of antimicrobial susceptibility to penicilloic beta-lactam antibiotics and first generation cephalosporins; the highest senitivity rates occurred among isolates from outpatients, followed in decreasing order by rates among isolates from non-ICU inpatients and from ICU-patients; the rate of use of this group of antimicrobial agents was relatively high in the intensive care unit (13,1%). For P. aeruginosa we observed significantly lower susceptibility-rates to second, third and fourth generation cephalosporins, carbapenems and monobactams for non-ICU inpatient areas than for outpatient or ICU areas; this paralleled with the low use of this group of agents in the ICU area (4,9%). Also, for P. aeruginosa the prevalence of susceptibility to ciprofloxacin and norfloxacin in inpatient areas was lower than in the outpatient or ICU-areas; the rate of quinolone-use was relatively low in the ICU area (4,2%).