Drug susceptibility of Pseudomonas aeruginosa strains isolated from patients of a hospital and specialistic outpatients clinics of the SP ZOZ in Nidzica

The aim of this study was to evaluate a frequency of isolation and antimicrobial susceptibility testing (AST) of Pseudomonas aeruginosa strains cultured from clinical specimens collected from patients hospitalized in wards and specialistic outpatients clinics of a hospital in Nidzica (01. 09. 2000 -31. 12. 2003). During over three years 392 Pseudomonas aeruginosa strains were cultured from 16346 clinical samples provided to bacteriological laboratory. P. aeruginosa strains were isolated from 2.5% of examined specimens. Susceptibility of Pseudomonas aeruginosa strains to antimicrobial agents was tested. The highest in vitro activity against clinical P. aeruginosa strains demonstrated imipenem. One strain was resistant to imipenem. This strain was isolated from a patient of a surgical department. Metalo-beta-lactamase was not detected (MBL-negative strain).Twenty nine strains were ESBL producer (7.4% of all strains). The contribution of Pseudomonas aeruginosa strains to the etiology of nosoconial and ambulatory infections increases. In vitro activity of antibacterial agents against P. aeruginosa strains should be monitored during therapy of infections. Resistance to antibiotics/chemothe-rapeutics may be acquired during treatment with antibacterial agent to which P. aeruginosa strain was susceptible according to the antibiogram.     

Sensitivity of Staphylococcus aureus strains isolated from the patients of the SP ZOZ Hospital in Nidzica to bacteriocidal agents

The aim of this study was to evaluate a frequency of isolation and antimicrobial susceptibility testing of Staphylococcus aureus strains isolated from clinical specimens obtained from patients hospitalized in different hospital wards (SP ZOZ) in Nidzica from 01. 09. 2000 to 31. 12. 2003. During over three years 716 Staphylococcus aureus strains were cultured out of 15517 clinical specimens supplied to the Bacteriological Laboratory of SP ZOZ in Nidzica. S. aureus strains were isolated from 4.6% of examined samples. Samples were collected from patients hospitalized in all wards (five wards). Analysis of susceptibility to antimicrobial agents of identified S. aureus strains was performed. Seventy strains (9.8%) were metihicillin-resistant (MRSA). One hundred twenty four strains (17.3%) revealed inducible resistance to macrolides, linkosamides and streptogramins B (MLS, mechanism). The greatest activity in vitro against clinical S. aureus strains showed glycopeptide antibiotic--vancomycin (100% of susceptible strains). Clinical S. aureus strains isolated from patients of hospital in Nidzica are in the majority susceptible to antibiotics/chemotherapeutics, except of penicillin. Percentage of methicillin-resistant strains (MRSA) is not high (<10). Nevertheless, constant monitoring of a drug susceptibility of nosocomial S. aureus strains is important, considering the necessity of control of current epidemiological and therapeutic situation.     

Characterization of antibody response to Pseudomonas aeruginosa in patients with wound infections

ELISA was used to measure the amount and avidity of IgG antibodies to exotoxin A (ExA) and 7 Fisher's immunotypes of lipopolysaccharide (LPS) in the sera of 13 patients with mild or moderate Pseudomonas aeruginosa infections. Changes in the specificity of tested sera during the course of infection were demonstrated. A statistically significant increase was seen in the amount and avidity of the antibodies to ExA in a majority of the sera, and an increase was seen in amount of antibodies to LPS immunotype 4 in the sera of patients with moderate infections.     

Transductional analysis of imipenem-ceftazidime-and azactam resistant Pseudomonas aeruginosa strains from nosocomial infections

Six strains of P. aeruginosa, resistant to IMI, CTZ and/or AZA, or to two of these drugs even to all three antibiotics, have been analysed by transduction by standard transducing phages F116 and G101, propagated on these strains, as well by a wildtype phage isolated from one of P. aeruginosa strains resistant to CTZ and AZA. Analysis of occurrence of resistance determinants in individual sets of transductants allows us to conclude that all three antibiotic-resistance determinants are separable by transduction and, thus, the resistance to any of these three antibiotics is genetically governed by independent determinants. None strain, resistant to these antibiotics, could hydrolyse any of these drugs, with an exception of slow hydrolysis of IMI, observed also by other investigators [8]. In contrast, strains hydrolysed classical, first-generation cephalosporins as well as Cefoxitin, and transferability of these two determinants could be proved by transfers, to Enterobacteriaceae (P. aeruginosa are naturally resistant to these two antibiotics). Thus, resistance to IMI, CTZ and/or AZA, is not co-transferred, with determinants of resistance to more classical cephalosporins.     

Typing of Pseudomonas aeruginosa strains in Turkish cystic fibrosis patients

The majority of cystic fibrosis (CF) patients suffer from chronic respiratory infection with the opportunistic bacterial pathogen Pseudomonas aeruginosa. The virulence of P. aeruginosa is associated with the presence of various extracellular factors, like alginate, elastase, alkaline protease which contribute tissue destruction and assist bacterial invasion. Virulence factor production of P. aeruginosa strains isolated from 46 CF patients followed in two cities in Turkey was detected. Strains were compared genotypically by arbitrarily primed PCR. Antimicrobial susceptibilities to 12 antibiotics were determined by broth microdilution method. Evaluation of virulence factor results revealed that 95.8% of the strains were alginate, 71.7% elastase and 52.1% alkaline protease producers. AP-PCR analysis revealed 35 genotypes indicated almost a complete discrepancy among the strains. The most effective drugs were penems and quinolones. Among aminoglycosides amikacin was the most effective one and a high level resistance to beta lactams was observed. Alginate is the most important virulence factor in the chronic colonisation of CF patients with P. aeruginosa. No evidence for cross infection between patients and for relationship between phenotypes and genotypes of the strains was found.     

Adherence of Pseudomonas aeruginosa strains to solid surfaces

The aim of this study was to evaluate adherence of 59 strains of Pseudomonas aeruginosa to nitric-acid cleansed glass surfaces. There were differences in adherence between the investigated strains. The highest adherence was noticed among human strains (the average percentage was 13.3 +/- 7.51%) and the lowest adherence was determined among swine strains (the average percentage amounted 6 +/- .37%). We conclude that strains of Pseudomonas aeruginosa isolated from humans colonise glass surfaces better than strains isolated from animals.     

用DNA杂交技术检测绿脓杆菌氨基糖甙类钝化酶基因的研究

目前已知的氨基糖甙类抗菌素钝化酶基因有许多种,2″—0—腺苷转移酶[ANT(2″)]基因为其中之一。本文从一株含ANT(2″)基因的重组质粒pFCT3103的基因克隆株,分离出310bp的ANT(2″)基因片段,将它制成基因探针,用该探针检查了30株绿脓杆菌是否含有氨基糖甙类钝化酶基因的存在情况,结果表明ANT(2″)基因的检出率为43.3%。     

健康人群和住院患者绿脓杆菌分离调查分析

本文调查了成都市第三人民医院住院病人,不同年龄组和不同标本PA绿脓杆菌的分离情况,经调查指出,住院病人PA分离率明显高于健康人群,而住院病人又以外科为最高。无论健康人群和住院病人,婴儿组和老年组均明显高于中青年组,尤以住院病人更为突出,故应对此类人群采取预防保护措施。不同标本分离率、健康人群和住院病人均以肛门分离率最高,分别为11.7％和21％,说明PA肠源性感染问题应引起重视。在所分离的菌株中,经血清学分型,住院病人的菌型十分集中,主要为1和6型二者合占56.7％,应当考虑到该医院存在医院感染问题。     

Contribution of macrophage secretory products to urovirulence of Pseudomonas aeruginosa

Macrophages form one of the first lines of defense on mucosal surfaces like urinary tract, providing protection against pathogens. These cells pour their secretory products, which include a cocktail of biomolecules, at the site of infection. In the present investigation, the effect of macrophage secretory products (MSPs) obtained after interaction of macrophages with Pseudomonas aeruginosa on the virulence of this organism in planktonic and biofilm cell mode was assessed employing a mouse model of ascending pyelonephritis. When urinary tract infection (UTI) was established with P. aeruginosa grown in the presence of 30% MSPs, the extent of pyelonephritis was enhanced. Of the two cell forms, biofilm cells had an edge over the planktonic cells with respect to in vivo virulence. The enhanced virulence of MSP-grown P. aeruginosa may be attributed to increased production of quorum-sensing systems as well as increased adherence to uroepithelial cells and evasion of phagocytosis. The results of the present study reveal that macrophages can play a key role during the course of UTI, not only through their phagocytic activity, but also through effects mediated by their secretory products. Utilization of MSPs by P. aeruginosa can have far-reaching consequences, including chronicity and recurrence of infections caused by this pathogen.     

亚胺培南对铜绿假单胞菌敏感和耐药菌株DNA释放的影响

目的：观察亚胺培南对铜绿假单胞菌标准菌株和耐药菌株体外培养释放DNA的影响。方法：选择铜绿假单胞菌的标准菌株和临床分离耐药菌株作为实验菌株,检测其亚胺培南的最低抑菌浓度（MIC）,琼脂糖凝胶电泳法观察不同浓度亚胺培南作用下铜绿假单胞菌的DNA释放情况,并用Quantity One软件分析所释放DNA片段的分子量和含量。结果：亚胺培南作用下铜绿假单胞菌从1／2MIC开始释放小片段DNA,大于1／2MIC仅释放l条大片段DNA,且含量少,等于1／2MIC可释放3条DNA,但无小片段DNA,小于1／2MIC可释放4．5条DNA,且含量多。1／16MIC时,标准菌株释放的第1、5条DNA片段含量偏少,3、4条DNA片段含量偏多,而耐药菌株相反。耐药菌株与标准菌株相比释放的DNA片段有所不同,耐药菌株比标准菌株多释放一条DNA片段（第2条）,分子量为2784bp,耐药菌株的第1、3、4、5条DNA片段分子量均比标准菌株小。耐药菌株释放的第3、4、5条DNA含量明显高于标准菌株,P〈0．01,其统计有显著学意义。结论：不同亚胺培南浓度作用下,铜绿假单胞菌会释放不同片段大小和含量的DNA分子,耐药菌株与标准菌株释放的DNA片段数量和含量有明显差异,其与耐药机制的关系值得进一步研究。     

Predominance of bacteriophage SP82 over bacteriophage SP01 in mixed infections of Bacillus subtilis

In mixed infections with Bacillus subtilis phages SP82 and SP01, the SP82 genotype is predominant among the progeny. This predominance is determined by a specific region of the genome, the pos region, which apparently is located near genes 29 to 32 (by the SP01 numbering system). Recombination between SP82 and SP01 yields phage which have both the SP82 pos region and an SP01 mutation. This mutation then behaves in mixed infection as if it were part of an SP82 genome.     

Pseudomonas aeruginosa infections are prevented in cystic fibrosis patients by avian antibodies binding Pseudomonas aeruginosa flagellin

Pseudomonas aeruginosa (PA) is the main cause of morbidity and mortality in cystic fibrosis (CF) patients. CF patients with chronic PA infections have a more rapid deterioration of their lung function and the bacteria become impossible to eradicate from the lungs. Antibiotic resistance among PA strains in CF patients is steadily increasing. Specific chicken (IgY) antibodies against PA have been shown to have potential to prevent PA infections in CF. Anti-Pseudomonas IgY reduces PA adhesion to epithelia, but the mechanism has not been fully elucidated. To gain further insight into the prophylactic effect of these antibodies, the immunoreactivity was investigated by 2D electrophoresis of PA strains, immunoblotting and MALDI-TOF-MS. To confirm the identity of the proteins, the tryptic peptides were analyzed by MALDI-TOF-MS to accurately measure their monoisotopic masses as well as determine their amino acid sequences. In order to facilitate fragmentation of the peptides they were N-terminally or C-terminally labeled. Several strains were investigated and anti-Pseudomonas IgY was immunoreactive against all of these strains, which strengthens its potential as a prophylactic treatment against PA. Flagellin was identified as the major antigen. Flagellin is the main protein of the flagella and is crucial for establishing infections in hosts as well as being involved in PA chemotaxis, motility, adhesion and inflammation. Furthermore, secreted flagellin elicits an inflammatory response. In conclusion, anti-Pseudomonas IgY binds flagellin, which may prevent PA infections in CF patients by hindering host invasion.     

铜绿假单胞菌注射液联合顺铂治疗消化道恶性腹腔积液的临床研究

目的：比较铜绿假单胞菌注射液联合顺铂与单纯使用顺铂治疗消化道恶性腹腔积液的疗效。方法：将250例消化道恶性中等量以上腹腔积液患者分为对照组和实验组各125例。所有患者行穿刺置管引流术,地塞米松预防发热,予盐酸利多卡因预防腹痛。铜绿假单胞菌注射液每周两次,顺铂每周一次,疗程一周,最多两个疗程。结果：实验组患者有效率为85．6％,其中,完全缓解40例,部分缓解67例。对照组例患者有效率为52％,其中,完全缓解24例,部分缓解4l例。两组比较差异有统计学意义（x2=32．87,P〈0．05）。实验组患者WHO体力状态评分（1分和2分）为104例,有效率为83．2％;对照组患者WHO体力状态评分（1分和2分）为72例,有效率为57．6％。两组比较差异有统计学意义（x2=19．67,P〈0．05）。结论：铜绿假单胞茵注射液联合顺铂腹腔内给药治疗消化道恶性腹腔积液。临床疗效显著。     

Storage of Pseudomonas strains degrading the surfactants

The survival rate and the destruction activity of Pseudomonas strains decomposing anionic and ampholytic surfactants were studied in the course of their storage for a long period of time. The strains were shown to remain viable and active after being freeze-dried for a year. Therefore, lyophilisation can be recommended as the main method of storage for bacterial strains decomposing the following surfactants: sulfoethoxylate, sulfonate, cyclimide, and amidobetaine.