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PubMed1994

[Alteration of serotype and drug susceptibility of some Pseudomonas aeruginosa isolates by exposure to human serum and polymorphonuclear leukocytes].

In the presence of 40% human serum plus polymorphonuclear leukocytes (PMNs, 10(7) cells/ml), changes in the surface properties of clinical isolates of P. aeruginosa were investigated by determining their serotypes and pyocin types as the markers. Furthermore, three isolates were tested for their susceptibility to anti-pseudomonal drugs and profiles of outer membrane proteins by the SDS-PAGE analysis. P. aeruginosa No. 21 which did not change in serotype and pyocin type after exposure to serum plus PMNs did not alter their susceptibility to all the drugs tested or their profiles of OMPs. In the case of P. aeruginosa No. 1-S, the variants with different serotypes were formed after the exposure, and increased their susceptibilities to some beta-lactams and norfloxacin which could penetrate into the bacterial cells through the porin channels of the outer membrane. Furthermore, two of the three type variants formed decreased their susceptibilities to gentamicin and polymyxin B which penetrated into the cells by the self-promoted uptake pathway. P. aeruginosa No. 1-R formed the serotype A and G variants with different pyocin types, only when exposed to serum plus PMNs for 24 hours, and the results were accompanied by the appearance of the porin D2 which was not detected in the parent cells. A small number of P. aeruginosa formed the variants with different serotypes and pyocin types owing to the alteration of their surface structures, when the cells were exposed to serum plus PMNs. The alterations were accompanied by the changes in some outer membrane proteins and the drug susceptibility to anti-pseudomonal drugs.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗
PubMed1973

Nursery outbreak of Pseudomonas aeruginosa: epidemiological conclusions from five different typing methods.

In April 1971, nine cases of Pseudomonas aeruginosa septicemia occurred in a high-risk nursery. The epidemiology of the outbreak was studied by pyocin production, pyocin sensitivity, serological typing, antibiotic susceptibility, and phenotypic properties such as colonial morphology, pigment, and hemolysis. Ten isolates of P. aeruginosa were recovered from 9 newborn infants and from 13 environmental sources. Twenty-one of the 23 isolates had identical pyocin production patterns against 60 different indicator strains and were of the same serotype. These 21 isolates were designated as the "outbreak strain"; the other 2 isolates had no epidemiological significance. The results of pyocin sensitivity, antibiotic susceptibility tests, and phenotypic properties were dissimilar. They would yield incorrect epidemiological conclusions if used alone. The outbreak strain dissociated in vitro and these phenotypic changes accounted for the variable results by the latter three typing methods. Although the precise mode of introduction of the organism into the nursery could not be determined in retrospect, the epidemiological data strongly suggested that one infant contracted a P. aeruginosa infection, and this strain spread throughout the nursery by means of contaminated resuscitation equipment.

Agglutination Tests↗
PubMed1991

Heterogeneity, persistence, and distribution of Pseudomonas aeruginosa genotypes in cystic fibrosis patients.

A collection of 222 isolates of Pseudomonas aeruginosa was obtained from the respiratory tract of 16 patients with cystic fibrosis over a 4- to 9-month period. Fourteen of these patients were unrelated, while the remaining two were siblings. Isolates were typed by conventional pyocin typing and also by the use of a DNA probe containing 741 bp immediately upstream of the exotoxin A structural gene and the initial 732 bp of the exotoxin A structural gene. By pyocin typing, 69% (11 of 16) of the patients were shown to harbor a single type that persisted in the lung throughout the study. By genotyping (DNA probe typing), all but three patients (13 of 16, 81%) harbored a single persistent genotype in their lungs. Six patients other than the sibling pair (6 of 14, 43%) shared a common genotype in their lungs as judged by DNA probing, and the pyocin type of these isolates was also identical. In four of these six patients, the shared genotype was also the persistent genotype. The sibling pair studied also carried a common genotype in their lungs as indicated by DNA probing, even though the pyocin type of these isolates varied. Results presented suggest that the majority of patients harbor a persistent strain in their lungs and that cross-colonization may occur.

Adolescent↗
PubMed1974

Evaluation of commercially available antisera for serotyping of Pseudomonas aeruginosa.

Commercially available O antisera have been compared with a standard pyocine typing method in the investigation of 156 strains of Pseudomonas aeruginosa. A third of the strains belonged to serotypes 3 or 6 and 42.3% to pyocine type 1. Good differentiation of strains belonging to the predominant serotypes was achieved by pyocine typing. Although routine use of both methods provides a more complete discrimination between strains, the simplicity of serotyping renders it more suitable for use in the smaller laboratory, where only one method may be feasible. If desired, pyocine typing can be reserved for the strains which cannot be distinguished serologically.

Agglutination Tests↗
PubMed1991

Vegetables as a source of infection with Pseudomonas aeruginosa in a University and Oncology Hospital of Rio de Janeiro.

Samples of fresh vegetables fed to patients in an Oncology and a University Hospital were examined for frequency of recovery and counts of Pseudomonas aeruginosa. Thirty-eight isolates from vegetables as well as 98 clinical isolates recovered during the same period of vegetable collection were serotyped and assayed for pyocin production in order to evaluate the role of vegetables as a source of microorganisms. Pseudomonas aeruginosa was recovered from 19.0% of the vegetable samples. Although 1% hypochlorite solution was used as a sanitizer, 50% of the positive samples were found to harbour more than 100 colony-forming units (cfu) g-1. Lettuce, chicory and watercress yielded the highest frequencies of isolation (P less than 0.05). The pyocin typing and serotyping of clinical strains revealed some types identical to those recovered from vegetables. Among those found in the University Hospital, serotype O4 and pyocin type PT10/b were detected in vegetables and in clinical specimens whereas types O1-PT22/e, O2a-PT10/a, O2a-PT10/b, O4-PT10/a, O11-PT10/a and O11-PT10/b were common in both groups of strains isolated in the Oncology Hospital. Our results strongly suggest that vegetables represent a source of endemic infection with P. aeruginosa for hospitalized patients.

Bacterial Typing Techniques↗
PubMed1991

Epidemiological typing of uropathogenic Pseudomonas aeruginosa strains from hospitalized patients.

One hundred and twenty-one clinical isolates of Pseudomonas aeruginosa from patients with hospital-acquired urinary tract infections (UTIs) were studied to determine their major epidemiological markers, including API 20NE profile, O-serotype, pyocin type, phage type, lysogenic state and antibiotic susceptibility. Serotypes O4, O12, O11, O6 and O5 were found with a high frequency, accounting respectively for 23.9%, 23.1%, 12.3%, 8.2% and 5.7% of isolates. Pyocin type 10 was most common (32.2%) followed by types 1 (10.7%), 33 (7.5%) and 105 (4.1%); subtype h was predominant being characteristic of 34.7% of isolates. Most of the strains (69.4%) were either not phage typable or sensitive to phages 68 and 119x. Resistance to gentamicin, tobramycin, amikacin, imipenem and ciprofloxacin was more frequent among strains belonging to serotype O12. The O-serotypes were combined with API 20NE profiles, pyocin and phage types, lysogenic states and antibiotic resistance in order to identify epidemiologically related clones. Within predominant serotypes--O4 and O12--most strains displayed similar but not identical type characteristics, whereas other serotypes were less homogeneous. Our results support the concept that a combination of current typing techniques allows the identification of epidemiologically related P. aeruginosa isolates.

Bacterial Typing Techniques↗
PubMed1976

Pseudomonas carrier rates of patients with cystic fibrosis and of members of their families.

The majority (86.6%) of patients with cystic fibrosis were found to be carriers of Pseudomonas aeruginosa. None of them, however, carried P. aeruginosa in their nares. In contrast, none of the non-CF family members of the patients with CF were carriers of P. aeruginosa. For example, only 4 of 468 cultures from skin, throat, and nares of the family members were positive for P. aeruginosa. Isolations of P. aeruginosa from the same CF patients were often of the same pyocine type. No specific pyocine type of P. aeruginosa was predominant in patients with CF. Isolations of P. aeruginosa from siblings with CF may or may not be of the same pyocine type as that of the family proband. Colonization of a patient with CF by P. aeruginosa is not a threat to the non-CF members of the family.

Adolescent↗
PubMed1983

Bacteremia due to Pseudomonas aeruginosa: use of a combined typing system in an eight-year study.

P aeruginosa bacteremia is a nosocomial disease with a high mortality occurring in colonized, debilitated, and leukopenic patients and in those receiving immunosuppressive and antimicrobial agents [2]. Outbreaks of P aeruginosa bacteremia have often been associated with environmental reservoirs [3]. The 190 strains of P aeruginosa described in this study represent single isolates from bacteremic patients during an eight-year period. Representing about 50% of total isolates, the most common pyocin types were 1b, 3, and 10, immunotypes 1, 2, and 3 + 7, and serotypes 11, 6, and 1. Of the 37 known pyocin types, only 10 were represented in this study. All seven immunotypes and 14 of 17 serotypes were found. The overall typability for each of the three techniques was 88%-90%; however, the largest numbers of typable patterns were found when all three typing methods or pyocin and either immunotyping or serotyping were used. The smallest number of typing patterns occurred when immunotyping and serotyping were performed together. Correlation among the following types was greater than 50%; pyo 3:immuno 1:sero 6; pyo 10:immuno 2:sero 11, and pyo NI:immuno 4:sero 1. Upon repeated testing the reproducibility of types for each technique was 98%-100%. For the most precise epidemiologic studies of P aeruginosa infections all three typing methods should be employed.

Humans↗
PubMed2006

PBP3 inhibition elicits adaptive responses in Pseudomonas aeruginosa.

Adaptive evolution depends on both the genetic variability in a population of organisms and the selection of the better adapted genotypes. However, for the fittest variants to be selected they must survive over a sufficient period under the new conditions. Bacteria are often exposed to different types of stress in nature, including antibiotics. We analysed the global expression profiles of the opportunistic pathogen Pseudomonas aeruginosa in response to ceftazidime, a PBP3 inhibitor, at different concentrations and times. PBP3 inhibition exerts a global impact on the transcription of a large number of genes. From an adaptive perspective, it is noteworthy the induction of several SOS genes, as well as adaptation, protection and antibiotic resistance genes. Intriguingly, transcription of pyocin genes, previously described as SOS-regulated, was repressed upon PBP3 inhibition. Ciprofloxacin, an SOS inducer, produced transcriptional induction of pyocins. Our results indicate that: (i) the SOS responses resulting from treatments with these two antibiotics cause only partially overlapping transcription profiles; (ii) PBP3 and DNA-gyrase inhibition produce opposite effects on transcription of pyocin genes. Consequently, ceftazidime decreases ciprofloxacin toxicity; (iii) error-prone DNA-polymerase DinB is induced by PBP3 inhibition but not by DNA-gyrase inhibition; (iv) PBP3 inhibition causes induced mutagenesis; (v) ceftazidime upregulates several antibiotic-resistance and adaptation genes; and (vi) ceftazidime concentrations thought previously to be lethal are not, as most cells treated with ceftazidime remain alive and recover their capacity to form colonies. Thus, transcriptional changes demonstrated in this work are likely to be adaptively relevant to cells that survive.

Adaptation, Physiological↗
PubMed1998

Antibiotic stress induces a large amount of outer membrane protein in Pseudomonas aeruginosa.

To investigate the bacterial response to antibiotic stress, we analyzed the outer membrane proteins of Pseudomonas aeruginosa grown in the presence of a sub-minimum inhibitory concentration of antibiotics. Among the antibiotics tested, fluoroquinolones and streptonigrin induced a large amount of outer membrane protein with a molecular mass of 43 kDa. This protein is most likely the stress-responsive protein, since the quinolone-resistant mutants with a higher minimum inhibitory concentration of antibiotic than the wild-type strain produced a large amount of 43-kDa protein only in the presence of sub-minimum inhibitory concentration of the mutants itself, but not that of the antibiotic-susceptible wild-type strain. The sequence of N-terminal 15 amino acids of the 43-kDa protein was identical to that of pyocin R1. However, purified pyocin R1 failed to accumulate in the outer membrane. Thus, we concluded that the 43-kDa protein (pyocin R1) is the antibiotic-stress-induced outer membrane protein.

Amino Acid Sequence↗
PubMed1974

Properties of R plasmids determining gentamicin resistance by acetylation in Pseudomonas aeruginosa.

Two clinical isolates of Pseudomonas aeruginosa, one a pyocin type 5 strain from Atlanta, could transfer gentamicin resistance by conjugation. Donor and recipient strains inactivated gentamicin by acetylation. The R plasmids, pMG1 and pMG2, also determined resistance to sisomicin, another substrate of gentamicin acetyltransferase I, sulfonamides, and streptomycin, but not resistance to kanamycin, neomycin, tobramycin, butirosin, or BB-K 8. They were transmissible to many strains of P. aeruginosa, including a Rec(-) strain, but not to Escherichia coli or other enterobacteriaceae. These R plasmids were compatible with R plasmids transmissible to P. aeruginosa from E. coli, including members of C, N, P, and W incompatibility groups. From a strain carrying pMG1 and a compatible plasmid, pMG1 was transferred independently but transfer of the second plasmid often resulted in cotransfer of pMG1. In contrast, pMG1 and pMG2 were incompatible with pseudomonas R plasmids R931 and R3108, and with R931 they readily formed recombinant plasmids. The four plasmids in this incompatibility group determine additional biological properties, including resistance to inorganic and organic mercury compounds, to ultraviolet light, and to certain deoxyribonucleic acid phages. pMG1 and pMG2 also phenotypically inhibited pyocin production. Consequently such R plasmids alter the phage and pyocin types of their host strains.

Acetylation↗
PubMed2005

PtrB of Pseudomonas aeruginosa suppresses the type III secretion system under the stress of DNA damage.

In a search for regulatory genes of the type III secretion system (TTSS) in Pseudomonas aeruginosa, transposon (Tn5) insertional mutants of the prtR gene were found defective in the TTSS. PrtR is an inhibitor of prtN, which encodes a transcriptional activator for pyocin synthesis genes. In P. aeruginosa, pyocin synthesis is activated when PrtR is degraded during the SOS response. Treatment of a wild-type P. aeruginosa strain with mitomycin C, a DNA-damaging agent, resulted in the inhibition of TTSS activation. A prtR/prtN double mutant had the same TTSS defect as the prtR mutant, and complementation by a prtR gene but not by a prtN gene restored the TTSS function. Also, overexpression of the prtN gene in wild-type PAK had no effect on the TTSS; thus, PrtN is not involved in the repression of the TTSS. To identify the PrtR-regulated TTSS repressor, another round of Tn mutagenesis was carried out in the background of a prtR/prtN double mutant. Insertion in a small gene, designated ptrB, restored the normal TTSS activity. Expression of ptrB is specifically repressed by PrtR, and mitomycin C-mediated suppression of the TTSS is also abolished in a ptrB mutant strain. Therefore, PtrB is a new TTSS repressor that coordinates TTSS repression and pyocin synthesis under the stress of DNA damage.

Bacterial Proteins↗
PubMed1996

Comparison of three typing methods for Pseudomonas aeruginosa.

Fifty-seven independent isolates of Pseudomonas aeruginosa from blood specimens were typed with 3 different methods: ribotyping, random amplified polymorphic DNA (RAPD) typing, and pyocin typing. Ribotyping was performed by probing the rRNA genes of genomic DNA that was digested separately with 4 different restriction enzymes. Digestion of DNA from 57 P. aeruginosa isolates with BamHI, ClaI, EcoRI, and PstI produced 4, 4, 6, and 7 patterns, respectively. As a result, ribotyping classified the 57 isolates into 22 types. Six new ribotypes that had not been described previously were found. One BamHI, 1 ClaI, 2 EcoRI, and 2 PstI patterns were novel. RAPD typing was performed with two different polymerase chain reaction (PCR) primers (RAPD1 and RAPD2). Both primers classified the 57 isolates into 15 RAPD types and produced identical patterns. The pyocin typing method classified the 57 isolates into 10 types. According to the results obtained in this study, the ribotyping has a discriminatory index of 0.865, RAPD, 0.785, and pyocin typing, 0.676, respectively. The ribotyping method was the most effective among the 3 methods compared for typing P. aeruginosa isolates.

Bacterial Typing Techniques↗
PubMed1991

Genome fingerprinting as a typing method used on polyagglutinable Pseudomonas aeruginosa isolates from cystic fibrosis patients.

Phenotypical changes occur in the surface of Pseudomonas aeruginosa during the chronic lung infection of cystic fibrosis patients. It is difficult with the classical typing methods, such as serotyping, phage typing and pyocin typing, to decide if a patient has been colonized with a new strain or whether it is the same strain which has reappeared, for instance after chemotherapy in the lungs. This investigation was carried out to evaluate genome fingerprinting as a typing method and to see how it correlated with classical methods and with DNA probe typing. Forty Pseudomonas aeruginosa isolates, 34 polyagglutinable and six monoagglutinable, from 14 cystic fibrosis patients were analysed using genome fingerprinting. The bacterial chromosomes were digested with the restriction endonucleases Dra 1 and Xbal, and separated by field inversion gel electrophoresis. The results were compared with those of a previous work (Ojeniyi et al. 1990) concerning typing with a DNA probe, serotyping using both polyclonal and monoclonal sera, phage typing, pyocin typing and reverse phage typing. The results of genome fingerprinting and DNA probe typing showed the best correlation, followed by pyocin typing. The correlation between the results of genome typing and the other typing methods was low. The discriminatory effect of genome fingerprinting was higher than that of DNA probe typing, and genome fingerprinting was found to be the best single method for epidemiological investigations of polyagglutinable isolates from cystic fibrosis patients.

Antibodies, Monoclonal↗
PubMed1977

Effect of bacteriocins on interferon production.

The level of interferon induced with NDV in human diploid cell cultures treated with pyocins was decreased compared with the control culture. This effect was maximal when pyocins were given simultaneously with interferon inducers. In experiments in vivo it was shown that pyocin itself induced very small amount if any of interferon, but administered together with NDV inhibited production of circulating interferone in mice. Similar decrease of interferon production was found when other bacteriocins, namely pneumocin 114 or E-47 aerocin, were used.

Animals↗
PubMed1983

[Studies on Pseudomonas aeruginosa typing in Turkey].

Several investigators has been found the serotypes of Ps. aeruginosa in Turkey by comparing with Habs, Sandvik, Veron, Meitert and Homma's serotypes. Habs's 0 : 3, 0 : 7, 0 : 11, Veron's 0 : 2b, Meitert's 0 : 15 0 : 13, 0 : 4, 0 : 5, Homma's 0 : 15, 0 : 2, 0 : 7, 0 : 13, 0 : 16 Serotypes found to be majority of the serotypes of the Ps aeruginosa in these researches. Meitert's phage set has been used in the bacteriophage typing of Ps. aeruginosa. Ia phage type found to be predominant phage type in Turkey. In addition to that pyocin types of Ps. aeruginosa was fund by using active pyocin typing method, pyocin types 3, 5, 27 were in majority in these investigations.

Bacteriophage Typing↗
PubMed2001

Impact of Heavy Metals on the Selective Phenotypical Markers of Pseudomonas aeruginosa.

The aim of this study was to characterize the impact of heavy metals on phenotypical markers of Pseudomonas aeruginosa. Twenty-two isolates of P. aeruginosa, either clinical (20) or secondary treated wastewater (2), were used to inoculate micro-ecosystems of sterile distilled water or secondary waste effluent in the presence of subminimal inhibitory concentrations of a variety of heavy metals commonly encountered in the aquatic naturally habitat (Ca2+, Co2+, Cr3+, Cu2+, Hg2+, Ni2+, Zn2+). Micro-ecosystems were exposed to visible light at laboratory temperature and individual strains were reisolated after a 1-, 3-, or 6-month period. The re-isolates (129) were characterized using hierarchical classification analysis in order to define affinities among variants of P. aeruginosa. Subsequently, discriminant analysis was used to detect eventual relationships among the different phenotypical markers studied. Results of the hierarchical classification, based on qualitative or quantitative approaches, showed clearly that incubation of P. aeruginosa in the presence of heavy metals altered the studied phenotypical markers, namely serotype, phage type, MIC of metals, and pyocin type. Discriminant analysis showed that the studied phenotypical markers could be classified into four clusters: C1 (L1 and L2 phage types, Hg tolerance and/or resistance, S2 serotype), C2 (P2 pyocin type, Cd tolerance and/or resistance, S1 serotype), C3 (Co and Cr tolerance and/or resistance) and C4 (P1 pyocin type, Ni, Zn, and Cu tolerance and/or resistance).

Journal Article↗
PubMed1993

Colonization of intensive care unit patients by Pseudomonas aeruginosa.

Colonization and infection by Pseudomonas aeruginosa was found at several sites by selective culture in 32 of 66 patients in an intensive care unit. Twenty-four patients (75%) were colonized on admission, and eight patients (25%) acquired P. aeruginosa during hospitalization. Positive rectal cultures were more frequent than at any other site. The most common P. aeruginosa serotypes were 1, 2, 3 and 5, and pyocin types 1, 3, 5 and 10 were predominant. There were no significant differences in the serotypes or pyocin types detected on admission or acquired during hospitalization. The serotypes and pyocin types from the respiratory tract (trachea and nasopharynx) were different from those found in the rectum. Intubated patients were colonized more frequently than those not intubated and upper respiratory tract colonization correlated strongly with low initial arterial pH values.

Anti-Bacterial Agents↗