DEVELOPMENT AND VALIDATION OF A LISTERIA MONOCYTOGENES HOST RESISTANCE MODEL IN FEMALE FISCHER 344 RATS

The mouse has been used almost exclusively as the experimental animal for host resistance studies in the United States. Host resistance models in mice have been validated and these types of studies are an integral part of the National Toxicology Program's (NTP) immunotoxicology testing program. Given that the Fischer 344 rat is the animal of choice for the NTP's toxicology studies, it was desirable to develop host resistance assays in this rat strain, eliminating the need to extrapolate doses between mouse and rat models. These studies were aimed at the development and the validation of a host resistance model to Listeria monocytogenes, a gram-positive, facultative intracellular bacterium, in the Fischer 344 rat. The results demonstrated that L. monocytogenes infection in the Fischer 344 rat produces a very similar disease with respect to onset and duration as in the mouse. Animals inoculated with up to 3 105 viable colony forming units (CFU) of L. monocytogenes were capable of resisting overt disease when they had an intact immune system. Inoculation of animals with 5 105 cfu resulted in 50% mortality (5/10). However, pretreatment with cyclophosphamide (an immunosuppressive agent) followed by administration of 5 105 L. monocytogenes resulted in 100% mortality. Conversely, pretreatment with Corynebacterium parvum (an immune-enhancing agent) followed by administration of 5 105 L. monocytogenes resulted in 100% survival of animals. Overt disease without recovery was manifested in vehicle-treated animals inoculated with 8 105 and 1 106 microorganism, while earlier deaths and 100% survival resulted after pretreatment with cyclophosphamide or C. parvum, respectively. These data support the use of the inbred Fischer 344 rat for host resistance assays.     

Antibiotic susceptibilities of livestock isolates of leptospira

Leptospirosis is the most common zoonotic disease and is endemic worldwide. The antibiotic susceptibilities of Leptospira strains isolated from both humans and animals are poorly documented. This issue is particularly important for isolates from food-producing animals which are regularly exposed to antibiotic treatments. This study assessed the susceptibility of 35 leptospira strains isolated from food-producing animals of diverse geographical origins between 1936 and 2016 to the antimicrobial agents used most commonly in animals. A broth microdilution method was used to determine the susceptibilities of Leptospira strains isolated from livestock to 11 antibiotics. All isolates were susceptible to penicillin, amoxicillin, clavulanate, cephalexin, ceftriaxone, doxycycline, tetracycline, streptomycin, enrofloxacin and spectinomycin, but not polymyxin [minimum inhibitory concentration (MIC)?≥?4?μg/L]. For tetracycline and doxycycline, the MIC was significantly higher for the recent isolates from Sardinia, Italy than for the other isolates. Antimicrobial susceptibilities were also determined with 10- and 100-fold higher inocula. High inocula significantly diminished the antibacterial effect by at least 10-fold for enrofloxacin (MIC ≥256?μg/L), streptomycin (MIC ≥16?μg/L) and tetracycline (MIC ≥32?μg/L), suggesting selection of resistant strains for high inocula. These findings contribute to the assessment of whether certain antibiotics are potentially useful for the treatment of leptospirosis, and point out the risk of failure for some antibiotics during infection with a high inoculum in both animals and humans. This study strengthens the need to detect and prevent the emergence of antimicrobial resistance of this major emerging zoonotic pathogen.     

解脲支原体对7种抗生素的体外敏感性测定

目的：了解非淋菌性尿道炎（NGU）患解脲支原体（UU）对7种抗生素的敏感性。方法：采用微量肉汤稀释法测定体外药物敏感性，对培养阳性的150例患进行了分析。结果：UU对7种抗生素的敏感性的顺序由高到低依次为：交沙霉素（96．67％）、强力霉素（90．67％）、美满霉素（88．67％）、司巴沙星（58．67％）、罗红霉素（39．33％）、氧氟沙星（18．00％）和阿奇霉素（8．00％）。UU耐药率最高的为氧氟沙星（31．33％），其次为司巴沙星（18．67％）和罗红霉素（18．00％）。结论：UU存在多重耐药，对UU进行药敏监测对指导临床合理用药及防止耐药株的发生有重要意义。     

The French antibiotic resistance monitoring programs

Surveillance of antimicrobial resistance in bacteria from animal origin in France is organised by the French Agency for Food Safety (Agence Française de Sécurité Sanitaire des Aliments, AFSSA) through two types of networks. The first collects non-human zoonotic Salmonella strains in one centre (AFSSA, Paris) where they are tested for their antimicrobial susceptibility. The others, managed by AFSSA Lyon, deal with bovine pathogenic strains and are multicentric, that is they collecting antibiotic sensitivity and other data from the local public veterinary diagnostic laboratories. This requires standardisation of the methods used in each partner laboratory. Statistical analysis of any change in French resistance patterns can be monitored by these three networks either as a function of strain pathogenicity and/or of the ecological origin of the isolate. The system also encourages efficient collaboration between veterinarians and the laboratory. Such collaboration improves both the quality of routine antibiotic testing and understanding of the molecular mechanisms underlying resistance.     

Bacteriophage P100 for control of Listeria monocytogenes in foods: genome sequence, bioinformatic analyses, oral toxicity study, and application

Listeria monocytogenes is an opportunistic foodborne pathogen responsible for Listeriosis, a frequently fatal infection. This investigation represents a comprehensive approach to characterize and evaluate the broad host range, strictly virulent phage P100, which can infect and kill a majority of Listeria monocytogenes strains. First, the complete nucleotide sequence (131,384 basepairs) of the genome of P100 was determined, predicted to encode 174 gene products and 18 tRNAs. Bioinformatic analyses revealed that none of the putative phage proteins has any homologies to genes or proteins of Listeria or any other bacteria which are known or suspected to be toxins, pathogenicity factors, antibiotic resistance determinants, or any known allergens. Next, a repeated dose oral toxicity study in rats was conducted, which did not produce any abnormal histological changes, morbidity or mortality. Therefore, no indications for any potential risk associated with using P100 as a food additive were found. As proof of concept, and to determine the parameters for application of P100 to foods sensitive to Listeria contamination, surface-ripened red-smear soft cheese was produced. Cheeses were contaminated with low concentrations of L. monocytogenes at the beginning of the ripening period, and P100 was applied to the surface during the rind washings. Depending on the time points, frequency and dose of phage applications, we were able to obtain a significant reduction (at least 3.5 logs) or a complete eradication of Listeria viable counts, respectively. We found no evidence for phage resistance in the Listeria isolates recovered from samples. Taken together, our results indicate that P100 can provide an effective and safe measure for the control of Listeria contamination in foods and production equipment.     

泌尿生殖道支原体临床分离株对7种抗菌药物的耐药性研究

目的 比较7种抗生索对泌尿生殖道支原体临床分离株的抗菌作用，指导临床用药。方法 采用直接肉汤药盘法测定了临床标本中146株解脲脲原体(Uu)和92株人型支原体(Mh)对7种抗菌药物的耐药性。结果 146株Uu对四环索、多西环索、米诺环素、罗红霉索、阿齐霉索、交沙霉索、氧氟沙星的耐药率分别为34．2％、24．7％、28．1％、8．9％、4．8％、11．0％、和28．8％。92株Mh对四环索、多西环索、米诺环索、罗红霉索、阿齐霉索、交沙霉索、氧氟沙星的耐药率分别为55．5％、25．0％、45．7％、97．8％、100％、8．7％、和16．3％。耐四环索的Uu和Mh株对多西环索、米诺环索、交沙霉索以及氧氟沙星存在交叉耐药性。850例Uu和Mh混合感染者对交沙霉索的耐药率最低(8．1％)。结论 泌尿生殖道支原体的耐药性监测对指导临床治疗具有重要意义。     

Evaluation of alternative antibiotics for susceptibility of gonococcal isolates from China

The efficacy of the currently recommended first-line treatments for gonococcal infections – ceftriaxone monotherapy or ceftriaxone/azithromycin dual therapy – is waning rapidly, and efficient alternative antimicrobials are needed urgently to ensure that future treatment of gonorrhoea remains available. As such, the aim of this study was to screen alternative clinically approved antimicrobials for in-vitro activity against Neisseria gonorrhoeae. The susceptibility levels of 504 clinical isolates from Zhejiang Province, China to ertapenem, tigecycline, gentamicin, fosfomycin, gemifloxacin, doxycycline and rifampicin were investigated using the agar dilution method. The presence of resistance determinants was identified by polymerase chain reaction and sequencing. The minimum inhibitory concentration inhibiting 90% of growth (MIC₉₀) was 0.06 mg/L for ertapenem, 0.25 mg/L for tigecycline, 16 mg/L for doxycycline, 4 mg/L for gemifloxacin, 16 mg/L for gentamicin, 32 mg/L for fosfomycin and 128 mg/L for rifampicin. All strains appeared to be susceptible to tigecycline (MIC ≤0.5 mg/L), while a poor correlation between tigecycline and tetracycline susceptibility was observed, indicating that tetracycline resistance determinants have little impact on tigecycline susceptibility. For ertapenem, 30 isolates showed an MIC >0.125 mg/L, but the correlation between ertapenem and ceftriaxone susceptibility was low and only two strains showed an MIC >0.125 mg/L for both antibiotics. Therefore, it appeared that most ceftriaxone-resistant isolates were still susceptible to ertapenem. In conclusion, tigecycline and ertapenem showed good activity against N. gonorrhoeae and limited cross-resistance with previously used antibiotics. Therefore, they might be interesting candidates for further evaluation of their suitability as alternative antigonococcal therapies.     

Antibiotic resistance, integrons and Salmonella genomic island 1 among non-typhoidal Salmonella serovars in The Netherlands

The objective of this study was to investigate the antimicrobial resistance patterns, integron characteristics and gene cassettes as well as the presence of Salmonella genomic island 1 (SGI1) in non-typhoidal Salmonella (NTS) isolates from human and animal origin. Epidemiologically unrelated Dutch NTS strains (n=237) originating from food-producing animals and human cases of salmonellosis were tested for their susceptibility to 15 antimicrobial agents. Resistance to 14 of these antimicrobials, including the third-generation cephalosporins, was detected. Resistance to sulphonamides, ampicillin, tetracycline, streptomycin, trimethoprim and nalidixic acid was common (>/=10% of the strains were resistant). Resistance against three or more antimicrobials was observed in 57 isolates. The same 237 strains were studied for the prevalence of class 1 integrons, their gene cassettes and the presence of SGI1. Thirty-six isolates (15.2%) carried class 1 integrons. These integrons had ten distinct profiles based on the size of the integron and restriction fragment length polymorphism analysis. Integrons were detected for the first time in serovars Indiana and Senftenberg. Multidrug resistance was strongly associated with the presence of class 1 integrons in which the aadA2, aadA1, bla(PSE-1), dfrA1, dfrA5, dfrA14 or sat genes were present, as determined by nucleotide sequence determination. The presence of gene cassettes or combinations of gene cassettes not previously found in integrons in Salmonella was observed. SGI1 or its variants (SGI-B, -C and -F) were present in 16 isolates belonging to either serovar Typhimurium, Derby or Albany. Regardless of whether the isolate was of human or animal origin, the same resistance phenotype, integron profile and SGI1 structure could be observed.     

Interaction of acylated and substituted antimicrobial peptide analogs with phospholipid-polydiacetylene vesicles. Correlation with their biological properties

A series of peptide analogs based on region 6-22 of Plantaricin 149 sequence were synthesized. The interaction between these analogs and phospholipid-polydiacetylene vesicles was investigated to evaluate the ability of the bioassay to detect differences in the interaction of the peptides with dipalmitoylphosphatidylglycerol and dipalmitoylphosphatidylcholine vesicles, associated with amino acid substitution and N-terminal conjugation of the sequences with short fatty acids (8 and 12 carbon atoms). Fatty acid conjugation of peptides with low antimicrobial activity resulted in lipopeptides with improved activity against strains of Staphylococcus aureus and Listeria monocytogenes. The length of the fatty acid determined the bacterial specificity, and the conjugation with n-octanoic acid yielded the most active analog (C8-CT) against Staphylococcus aureus strain (MIC: 1.0 μm) while the conjugation with n-dodecanoic acid (C12-CT) was optimal for Listeria monocytogenes strain (MIC: 2.0 μm). In contrast, the substitution of Phe by Trp had an unfavorable effect on the antimicrobial activity. Hemolysis tests and membrane interaction studies with dipalmitoylphosphatidylcholine-polydiacetylene vesicles showed that lipopeptides interact to a greater extent with both biological and biomimetic membranes. Also, a good correlation was found between antimicrobial activity against Staphylococcus aureus strain and % colorimetric response values with dipalmitoylphosphatidylglycerol-polydiacetylene vesicles.     

Antimicrobial susceptibility of potentially pathogenic halophilic vibrios isolated from seafood

Susceptibility patterns to 27 antimicrobial agents and beta-lactamase production were investigated in potentially pathogenic halophilic vibrios from seafood. The effect of salinity on the response to the drugs in vitro was also studied. All isolates were uniformly sensitive to choramphenicol, imipenem, meropenem but resistant to lincomycin. All were highly sensitive to oxolinic acid, trimethoprim-sulphamethoxazole, doxycycline, flumequine, cefotaxime, nalidixic acid and ciprofloxacin. Some strains of V. harveyi, V. alginolyticus and V. parahaemolyticus apparently had mechanisms of resistance to several beta-lactam antibiotics other than by the production of beta-lactamases. Sixty-nine strains produced penicillinase but a low correlation between beta-lactamase activity and resistance to beta-lactam antibiotics was noted. The salt concentration affected the in vitro susceptibility of halophilic vibrios and the effect of salinity depended on both the individual strains and the antimicrobial tested.     

Protective effect of a traditional Japanese medicine Hochu-ekki-to (Chinese name: Bu-zhong-yi-qi-tang), on the susceptibility against Listeria monocytogenes in infant mice

In this study, the effect of traditional Japanese (Chinese) medicine, Hochu-ekki-to, HOT (Chinese name: Bu-zhong-yi-qi-tang), on the susceptibility against Listeria monocytogenes in postneonatal infant mice was examined. Numbers of bacteria in infant mice (infected at 4 weeks of age) were significantly higher than those in adult mice (infected at 8 weeks of age) on day 3 (non-specific resistance phase) and day 5 (specific resistance phase) after infection. Oral administration of 1,000 mg/kg of HOT for 7 days to infant mice reduced bacterial numbers in the liver and spleen at 5 days after the infection. The amount of IFN-gamma and the number of IFN-gamma-producing CD4+ T cells were lower in infant mice than adult mice but those in infant mice enhanced by HOT treatment. HOT also enhanced the antigen-presenting function along with the expression of MHC class II in infant macrophages induced by heat-killed L. monocytogenes. Further, HOT enhanced the IFN-gamma production from infant CD4+ T cells independent of the deficiency in the antigen-presenting function. These findings suggest that HOT induced simultaneously functional maturation of both infant antigen-presenting cells and T cells, and consequently developed an anti-listerial Th1 response.     

Resistance determinants in strains of Clostridium difficile from two geographically distinct populations

Ninety-three clinical isolates of Clostridium difficile, comprising 65 from Royal Gwent Hospital, Newport and 28 from Southmead Hospital, Bristol were examined to determine the prevalence of genes coding for macrolide resistance and to explore differences in susceptibility patterns. Antibiogram testing produced similar results for both sets of strains with respect to amoxicillin, tetracycline, erythromycin and cefotaxime. Results differed for rifampicin, where 53% of the Bristol isolates were resistant, compared with 3% of the Newport isolates. Clindamycin disc susceptibility testing produced similar resistance rates. However, clindamycin MIC determinations revealed that 53% of the Bristol strains exhibited high-level resistance (MIC > 256 mg/L), whereas strains from Newport had clindamycin MICs ranging from 0.25 to 3 mg/L. erm (B) was present in 15 of the strains from Bristol and in none of the Newport strains. erm (F) and erm (Q) were not detected in either population. The two geographically distinct populations of C. difficile differed considerably in their susceptibility to antibiotics. The possibility that C. difficile may serve as a conservator for resistant determinants subsequent to exposure to antimicrobial agents, has important implications for infection control.     

In vitro activities of non-traditional antimicrobials alone or in combination against multidrug-resistant strains of Pseudomonas aeruginosa and Acinetobacter baumannii isolated from intensive care units

The aim of this study was to assess the in vitro activity of a number of non-traditional antibiotics (colistin, azithromycin, doxycycline and rifampicin) against multidrug-resistant (MDR) strains of Pseudomonas aeruginosa and Acinetobacter baumannii isolated from Intensive Care Units (ICUs). We also used the checkerboard method to determine whether combinations of colistin with another non-traditional antibiotic or meropenem act synergistically against these strains. Thirty-five P. aeruginosa and 25 A. baumannii strains that were found to be MDR were included the study. Isolates were collected from the specimens of patients in ICUs from 2001 to 2003. All isolates were identified by standard methods and stored at -20 degrees C until use. Antibiotic powders of azithromycin, doxycycline, rifampicin, meropenem and colistin were obtained from their manufacturers. Minimum inhibitory concentrations (MICs) were determined by the agar dilution method on Mueller-Hinton agar. Five strains of A. baumannii and five strains of P. aeruginosa, all of which had different MIC values for colistin, were selected for the synergy study using the checkerboard titration method. The susceptibility results for doxycycline and meropenem were interpreted according to National Committee for Clinical Laboratory Standards guidelines. The susceptibility breakpoints for colistin and rifampicin were established as 4 mg/L and 2 mg/L, respectively, based on previous studies. Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922 were used as control strains. Testing against the P. aeruginosa strains revealed high MIC50 values for all the drugs except colistin. Doxycycline and colistin were both effective against the A. baumannii strains, with high susceptibility rates of 92% and 100%, respectively. Azithromycin had a high MIC50 value against these strains, whilst rifampicin had a moderate effect (susceptibility rate 64%). The combination of colistin and rifampicin was fully synergistic against four A. baumannii and two P. aeruginosa strains. Combinations of colistin with meropenem and of colistin with azithromycin each showed synergistic activity against three A. baumannii isolates, whilst the same combinations resulted in generally additive or indifferent effects against P. aeruginosa strains. The colistin and doxycycline combination was generally partially synergistic or additive against all the isolates. MDR strains of P. aeruginosa and A. baumannii, which cause nosocomial infections with an increasing ratio in recent years, have limited treatment options. According to our in vitro study results, non-traditional antibiotics such as doxycycline and colistin can be an alternative for the treatment of infections caused by these strains. Combinations of colistin with non-traditional antibiotics or meropenem could be promising alternatives for the treatment of infections due to MDR strains of A. baumannii and P. aeruginosa.     

XENOBIOTIC-METABOLIZING ENZYMES IN CARP (CYPRINUS CARPIO) LIVER,SPLEEN, AND HEAD KIDNEY FOLLOWING EXPERIMENTAL LISTERIA MONOCYTOGENES INFECTION

Infection of carp with Listeria monocytogenes 4b resulted in decreased liver, spleen, and head kidney enzyme activities, involved in the metabolism of xenobiotics. After infection, cytochrome P-450 levels and ethoxyresorufin O-deethylase (EROD) activity were decreased while conjugation enzymes remained unaffected. The maximum decrease for phase I enzymes occurred on d 3. This loss of monooxygenase levels and activity could not be directly correlated with an increase in the number of organisms, as consistently high bacterial counts were observed in all three organs during infection. The effect of L. monocytogenes infection was also measured in carp exposed to 3-methylcholanthrene (MCA). Cytochrome P-450 levels and EROD activity were significantly reduced, especially on d 3. A significant decreased activity of conjugation enzymes such as glutathione S-transferase (GST) and UDP-glucuronosyltransferase (UDPGT) was also observed for all days studied. Listeria infection inhibited MCA-induced increases in xenobiotic-metabolizing enzyme activities. These results indicate that infection may have deleterious effects on basal cytochrome P-450 monooxygenase levels. Futhermore, MCA treatment aggravates the insult to xenobiotic biotransformation enzymes by L. monocytogenes infection, by impairing a number of detoxification enzymes. These findings could result in significant changes in the susceptibility of fish to pollutants.     

Thalidomide enhances both primary and secondary host resistances to Listeria monocytogenes infection by a neutrophil-related mechanism in female B6C3F1 mice

Previously, we have reported that thalidomide can modulate the immune responses in female B6C3F1 mice. Furthermore, thalidomide immunomodulation increased primary host resistance to intravenously infected Listeria monocytogenes. The present study was intended to evaluate the mechanisms underlying the enhanced host resistance to L. monocytogenes by focusing on the neutrophils. Female B6C3F1 mice were treated intraperitoneally with thalidomide (100 mg/kg) for 15 days. Exposure to thalidomide increased the numbers of neutrophils in the spleens and livers of L. monocytogenes-infected mice when compared to the L. monocytogenes-infected control mice. Additionally, the percentage of neutrophils was also significantly increased after Thd treatment in L. monocytogenes-infected mice. Further studies using antibodies to deplete corresponding cells indicated that thalidomide-mediated increase in primary host resistance (both the moribundity and colony counts in the liver and spleen) to L. monocytogenes infection was due to its effect on neutrophils but not CD8+ T cells or NK cells. Finally, Thd exposure also increased host resistance to secondary host resistance to L. monocytogenes infection, and depletion of neutrophils abolished the protective effect. In conclusion, thalidomide enhanced host resistance to both primary and secondary L. monocytogenes infections by a neutrophil-related mechanism in female B6C3F1 mice.     

Antimicrobial properties of aqueous extracts from three medicinal plants growing wild in arid regions of Tunisia

Seed extracts of three plant species that grow wild in the arid regions of Tunisia, Juniperus phoenicea L. (Cupressaceae), Pistacia atlantica Desf. (Anacardiaceae), and Oudneya africana R. Br. (Brassicaceae), were examined for antimicrobial activity against bacterial food pathogens. Aqueous extracts were prepared and then precipitated with methanol or acetone. Extracted acetone fractions (pH?7.2) showed powerful antimicrobial activity, especially against Listeria monocytogenes, Listeria innocua, and Listeria ivanovii (Gram-positive) and were also active against Gram-negative strains Escherichia coli and Pseudomonas aeruginosa. Extracts selected for high antimicrobial activity were stable in the presence of organic solvents (chloroform, hexane, acetonitrile, methanol, and acetone), and withstand thermal treatments up to 100°C for 30?min. L. monocytogenes LSD530 and E. coli ATCC 25922 appeared to be inhibited by Juniperus and Pistacia extracts with a minimum concentration of 1.56 and 3.?12?mg/mL, respectively. This study established the potential of medicinal plants growing wild in arid regions of Tunisia as a source of antimicrobial agents.     

男性非淋菌性尿道炎患者支原体感染及抗菌药物耐药率分析

目的 了解男性泌尿生殖道非淋菌性尿道炎患者（NGU）支原体感染及其耐药性状况,指导临床合理使用抗菌药物.方法 采用珠海银科试剂厂生产的支原体试剂盒进行支原体培养鉴定、计数和药敏试验,进行统计分析.结果 从1476份男性泌尿生殖道NGU标本中共检出663株支原体,阳性率为44.9%,其中解脲脲原体（Uu）563株（84.9%）,人型支原体（Mh）18株（2.7%）,Uu合并Mh阳性82株（12.4%）.检出支原体对美满霉素、强力霉素耐药率最低,对螺旋霉素、罗红霉素和环丙沙星的耐药率最高.结论 支原体已成为男性NGU的主要病原体并以Uu为主,已有多重耐药株的出现,美满霉素和强力霉素可作为治疗的首选药物.     

多重耐药铜绿假单胞菌的耐药性分析

目的分析2007年—2009年我院铜绿假单胞菌多重耐药(multidrug resistant,MDR)菌株对多种抗菌药物的耐药性变迁。方法收集2007年1月—2009年12月我院细菌室分离的铜绿假单胞菌,采用琼脂扩散法作敏感试验。结果 3年来共分离铜绿假单胞菌422株,其中MDR菌株100株,占23.70%。分离出的MDR菌株分布在呼吸科普通病房(13.00%)、呼吸重症监护病房(RICU)(29.00%)、外科病房(9.00%)、外科监护病房(SICU)(20.00%)、急诊科(5.00%)和其他内科病房(14.00%)。各科室中,分离出的MDR菌株数占所有标本分离的该菌株数的比例最高的是RICU(42.39%,39/92),其次为SICU(37.04%,20/54)。痰标本分离的MDR菌株占76.00%(76/100),其次为尿液(5.00%,5/100)。铜绿假单胞菌MDR菌株的分离率在3年期间无显著性差异。3年期间铜绿假单胞菌MDR菌株对头孢哌酮/舒巴坦耐药率最低(分别为25.00%、37.93%、40.48%);对所有检测的抗菌药物耐药率各年间无显著性差异。RICU与SICU分离的MDR菌株对亚胺培南、美罗培南耐药率显著高于其他普通病房,对其余检测的抗菌药物耐药率与其他病房无显著性差异。结论我院铜绿假单胞菌MDR菌株的耐药情况近年来十分严峻,在RICU与SICU,MDR菌株对碳青霉烯类耐药尤其严重,因此需严密监测细菌耐药性,指导合理使用抗菌药物。     

非淋菌性泌尿生殖道感染支原体检测及药敏试验

目的:了解解脲脲原体(Uu)和人型支原体(Mh)在非淋菌性泌尿生殖道感染中的致病作用及其体外药物敏感状况.方法:296例疑为非淋菌性泌尿生殖道感染的患者,运用微量稀释法进行支原体培养,测定解脲脲原体对10种抗菌药物的敏感性. 结果:101例(34.1%)支原体培养阳性,其中Uu阳性75例(25.3%),Mh阳性6例(2.0%),Mh＋Uu阳性20例(6.8%),女性(42.9%)支原体阳性率显著高于男性(28.8%).Uu对螺旋霉素均耐药,对氧氟沙星、四环素的耐药率均为37.3%,对交沙霉素的耐药率最低(8.0%), 对其他抗菌药物的耐药率依次为美满霉素(33.3%)、强力霉素(32.0%)、红霉素(30.7%)、左氧氟沙星(18.7%)、阿奇霉素(13.3%)、罗红霉素(10.7%).Uu对四环素类、大环内酯类和喹诺酮类有交叉耐药,以对四环素类和喹诺酮类的交叉耐药率最高(12.0%).结论:支原体的定期耐药性监测对临床用药有重要意义.     

2018—2020年多中心血流感染分离菌分布及耐药性分析

摘要：目的 分析2018—2020年多中心血流感染病原菌的分布及耐药演变特点,为临床合理选用抗菌药物提供可靠依据。 方法 采用药敏纸片法或仪器法,对11所三级医院按统一技术方案,进行细菌鉴定及药物敏感性试验,按2020年CLSI折点标准 判断结果,数据分析使用WHONET5.6。结果 11所三级医院3年血流感染标本共分离病原菌20742株,其中革兰阴性菌12399 株 (59.8%),革兰阳性菌8343株(40.2%);排名前3的依次为大肠埃希菌(5231株,25.2%)、肺炎克雷伯菌(2840株,13.7%)、表皮葡 萄球菌(1517株,7.3%)。3年药敏结果表明,大肠埃希菌对环丙沙星的耐药率均高于60.0%(62.8%、63.6%和66.3%);肺炎克雷伯 菌对碳青霉烯类耐药率逐年上升(16.7%、16.8%和21.6%),其中空军军医大学第一附属医院、昆明医科大学第一附属医院最高 36.2%和30.6%;MRSA检出率逐年下降(32%、31.6%和30.7%);非发酵革兰阴性杆菌铜绿假单胞菌对哌拉西林/他唑巴坦的耐药 率分别为10.2%、10.5%和7.5%;鲍曼不动杆菌对碳青霉烯类抗菌药物的耐药率较高(77.6%、76.7%和74.7%);屎肠球菌检出率 高于粪肠球菌,除利奈唑胺和四环素外,屎肠球菌的耐药性均高于粪肠球菌;布鲁菌共检出300株,其中宁夏医科大学总医院 检出最多(165株)。结论 11所医院血流感染病原菌3年检出及构成变化不大,以革兰阴性菌为主,大肠埃希菌和肺炎克雷伯菌占 绝对优势;大肠埃希菌对喹诺酮类耐药率较高;鲍曼不动杆菌耐药情况严重;布鲁菌所有成员单位均有检出,宁夏医科大学总 医院检出数最多。临床应持续加强细菌耐药监测以指导临床合理用药。