Comparative de novo transcriptome analysis and random UV mutagenesis: application in high biomass and astaxanthin production enhancement for Haematococcus pluvialis.

BACKGROUND: Astaxanthin is a natural carotenoid with strong antioxidant capacity. The high demand on astaxanthin by cosmetic, food, pharmaceutical and aquaculture industries promote its value in the biotechnological research. Haematococcus pluvialis Flotow 1844 has been characterized as one of the most promising species for natural astaxanthin biosynthesis. Even though H. pluvialis as an advantage in producing astaxanthin, its slow grow-yield limits usage of the species for large-scale production. METHODS AND RESULTS: In this study we generated mutated H. pluvialis strain by using one-step random UV mutagenesis approach for higher biomass production in the green flagellated period and in turn higher astaxanthin accumulation in red stage per unit algae harvest. Isolated mutant strains were tested for the astaxanthin accumulation and yield of biomass. Among tested strains only mutant strain designated as only MT-3-7-2 showed a consistent and higher growth pattern, the rest had shown a fluctuated and then decreased growth rate than wild type. To demonstrate the phenotypical changes in MT-3-7-2 is associated with transcriptome, we carried out comparative analysis of transcriptome profiles between MT-3-7-2 and the wild type strains. De novo assembly was carried out to obtain the transcripts. Differential expression levels for the transcripts were evaluated by functional annotation analysis. CONCLUSIONS: Data showed that increased biomass for the MT-3-7-2 strain was different from wild type with expression of transcripts upregulated in carbohydrate metabolism and downregulated in lipid metabolisms. Our data suggests a switching mechanism is enrolled between carbohydrate and lipid metabolism to regulate cell proliferation and stress responses.

Effects of moderate high temperature and UV-B on accumulation of withanolides and relative expression of the squalene synthase gene in Physalis peruviana.

Physalis peruviana L. (Cape gooseberry) is a source for a variety of phytocompounds such as withanolides, withanone, withaferin A, and withanolide A. These withanolides are high-value drug candidates due to their various pharmacological properties. To meet the increasing demands for these compounds, plant cell technology offers a reliable alternative. Exogenous addition of elicitors is considered the most effective strategy for enhanced production of secondary metabolites. In this study, we investigated changes in withanolide accumulation and characterized the gene expression level changes of squalene synthase enzyme in P. peruviana shoot cultures exposed to mild nonlethal heat stress (45°C for 2 and 5 h) and UV-B radiation (313 nm for 15 min and 3 h). We demonstrated significant changes in withanolide content with 7.86- and 12.5-fold increases for 2- and 5-hmild high-temperature exposure times, respectively. Exposure to UV-B also changed the withanolide content by 7.22- and 7-fold increases for 15 min and 3 h exposure times, respectively. The relative expression level of squalene synthase gene showed consistent results with1.80- and 10.13-fold increases in withanolide for 2- and 5-h mild high-temperature exposure times, and 1.34- and 2.01-fold increases with 15 min and 3 h UV-B exposure times, respectively.

Nematode-Associated Bacteria: Production of Antimicrobial Agent as a Presumptive Nominee for Curing Endodontic Infections Caused by Enterococcus faecalis.

Xenorhabdus and/or Photorhabdus bacteria produce antibacterial metabolites to protect insect cadavers against food competitors allowing them to survive in nature with their nematode host. The effects of culture supernatant produced by Xenorhabdus and Photorhabdus spp. were investigated against the multidrug-resistant dental root canal pathogen Enterococcus faecalis. The efficacy of seven different cell-free supernatants of Xenorhabdus and Photorhabdus species against E. faecalis was assessed with overlay bioassay and serial dilution techniques. Additionally, time-dependent inactivation of supernatant was evaluated. Among the seven different bacterial species, X. cabanillasii produced the strongest antibacterial effects. Loss of bioactivity in a phosphopantetheinyl transferase-deficient mutant of X. cabanillasii indicated that this activity is likely based on non-ribosomal peptide synthetases (NRPSs) or polyketide synthases (PKSs). Subsequent in silico analysis revealed multiple possible biosynthetic gene clusters (BGCs) in the genome of X. cabanillasii including a BGC homologous to that of zeamine/fabclavine biosynthesis. Fabclavines are NRPS-derived hexapeptides, which are connected by PKS-derived malonate units to an unusual polyamine, also PKS-derived. Due to the known broad-spectrum bioactivity of the fabclavines, we generated a promoter exchange mutant in front of the fabclavine-like BGC. This leads to over-expression by induction or a knock-out by non-induction which resulted in a bioactive and non-bioactive mutant. Furthermore, MS and MS2 experiments confirmed that X. cabanillasii produces the same derivatives as X. budapestensis. The medicament potential of 10-fold concentrated supernatant of induced fcl promoter exchanged X. cabanillasii was also assessed in dental root canals. Calcium hydroxide paste, or chlorhexidine gel, or fabclavine-rich supernatant was applied to root canals. Fabclavine-rich supernatant exhibited the highest inactivation efficacy of ≥3 log10 steps CFU reduction, followed by calcium hydroxide paste (≤2 log10 step). The mean percentage of E. faecalis-free dental root canals after treatment was 63.6, 45.5, and 18.2% for fabclavine, calcium hydroxide, and chlorhexidine, respectively. Fabclavine in liquid form or preferably as a paste or gel formulation is a promising alternative intracanal medicament.

TST, QuantiFERON-TB Gold test and T-SPOT.TB test for detecting latent tuberculosis infection in patients with rheumatic disease prior to anti-TNF therapy.

Introduction: Before starting tumour necrosis factor (TNF)-α blocking agents, standard tests should be used for the diagnosis of tuberculosis infection. The specificity of traditional tuberculin skin test (TST) is low in immunosuppressed patients due to prior Bacille Calmette Guérin (BCG) vaccination, non-tuberculous mycobacteria infections, false positive and negative results. In this study, we aimed to compare TST and Interferon-Gamma Release Assay (IGRA) tests for detecting latent tuberculosis infection in patients with rheumatic disease planned to receive TNF-α blocking agents. Materials and Methods: One hundred and nine patients (45 male, 64 female) with the diagnosis of rheumatoid arthritis (RA) (n= 70) and ankylosing spondylitis (AS) (n= 39) were included in the study. Age, sex, number of BCG scar, results of TST (using the Mantoux method), QuantiFERON-TB Gold test and T-SPOT.TB test were recorded for all patients. Correlation between the tests was assessed by Pearson correlation coefficient. Result: The mean age of RA and AS patients were 50 ± 13 (19-78 years). The prevalence of latent tuberculosis was 43.1% for TST, 39.4% for QuantiFERON-TB Gold test and 13.8% for T-SPOT.TB test, compared with the evaluation using the composite criteria such as close contact with active tuberculosis infection and/or suspicious fibrotic/calcific lesions on chest X-Ray without active tuberculosis infection. There was a moderate correlation between BCG scar number and TST (p< 0.001, r= 0.495), T-SPOT.TB test and QuantiFERON-TB Gold test (p= 0.007, r= 0.406), T-SPOT.TB test and composite criteria (p= 0.024, r= 0.343). The specificity of QuantiFERON-TB Gold test was 85.7%, and sensitivity was 73.9% for all patients with rheumatic disease. It was 73.5% and 66.7% for T-SPOT.TB test, respectively. The specificity of TST was 60.3% and sensitivity was 47.8% for TST. Conclusions: IGRA tests are not affected prior vaccination and useful for detecting latent tuberculosis infection in patients treated with corticosteroid due to lack of correlation between test negativity and corticosteroid therapy. Also, they are useful tests for diagnosis of latent tuberculosis infection as an alternative to TST due to their specificity and sensitivity.

Draft Genome Sequence of JVAP01T, the Type Strain of the Novel Species Acinetobacter dijkshoorniae.

Here, we report the draft genome sequence of the type strain of Acinetobacter dijkshoorniae, a novel human pathogen within the Acinetobacter calcoaceticus-Acinetobacter baumannii (ACB) complex. Strain JVAP01T has an estimated genome size of 3.9 Mb, exhibits a 38.8% G+C content, and carries a plasmid with the blaNDM-1 carbapenemase gene.

[Evaluation of the efficacy of colistin/sulbactam combination on carbapenem-resistant Acinetobacter baumannii strains]. / Karbapeneme dirençli Acinetobacter baumannii suslarinda kolistin/sulbaktam kombinasyonu etkinliginin degerlendirilmesi.

Acinetobacter baumannii strains, are opportunistic pathogens that cause severe nosocomial infections that are difficult to treat due to development of resistance to multiple antibiotics. As the antibiotic choices to be used in treatment are limited, combinations of a variety of antibiotics are used. The aims of this study were to identify the minimal inhibitory concentration (MIC) values of colistin and sulbactam against A.baumannii isolates and to determine the in vitro activity of colistin-sulbactam combination. A total of 50 A.baumannii strains isolated from different clinical specimens (32 tracheal aspirates, 10 blood, 6 urine and 2 wound samples) were included in the study. The identification of bacteria was performed by traditional methods and Vitek-2 (BioMerieux, France) automated system. Antibiotic susceptibilities were detected by Mueller-Hinton agar disk diffusion method and Vitek-2 automated system and the results were interpreted according to the CLSI standards. MIC values of colistin and sulbactam against A.baumannii strains and in vitro interactions of colistin-sulbactam combinations were determined with the E-test (BioMerieux, France). Fractional inhibitory concentration (FIC) index was used for the detection of efficacy of drug combinations. The presence of oxacillinase and metallo-beta-lactamase (MBL) genes that lead carbapenem resistance was investigated by polymerase chain reaction (PCR), and pulsed-field gel electrophoresis (PFGE) was performed for the determination of clonal relationship. In our study, all strains (100%) were detected as susceptible to colistin, 48 (96%) to trimethoprim/sulphamethoxazole and 18 to (36%) tigecyclin; however all of them were resistant to the other studied antibiotics, including sulbactam and carbapenem. When the colistin-sulbactam combination was assessed according to FIC index, all strains were found to have antagonistic effect. All of the carbapenem-resistant strains were positive for OXA-51 and OXA-23, and 3 (6%) were positive for OXA-24. Among MBLs, OXA-58, OXA-48, IPM, SPM, SIM, GIM, VIM and NDM-1 genes were not detected. In the evaluation of PFGE results it was found that the clonal distribution of the strains, except one, were all pulsotype A. In the assessment of in vitro efficacy of the colistin-sulbactam combination against A.baumannii strains with multidrug resistance, antagonistic effect was observed in all strains. In the resistance and clonal analysis it was determined that the strains belonged to the same clone, and they had the same resistance genes and therefore the result of the in vitro activity was considered to have similar effect among all strains. It was decided that especially in units where critical patients are monitored and where resistant strains that are difficult to treat are isolated, performing synergy studies may be beneficial for the selection of combination treatment and the determination of the treatment combination to be chosen specifically for the hospital or even the unit.

Acinetobacter dijkshoorniae sp. nov., a member of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex mainly recovered from clinical samples in different countries.

The recent advances in bacterial species identification methods have led to the rapid taxonomic diversification of the genus Acinetobacter. In the present study, phenotypic and molecular methods have been used to determine the taxonomic position of a group of 12 genotypically distinct strains belonging to the Acinetobacter calcoaceticus-Acinetobacter baumannii (ACB) complex, initially described by Gerner-Smidt and Tjernberg in 1993, that are closely related to Acinetobacter pittii. Strains characterized in this study originated mostly from human samples obtained in different countries over a period of 15 years. rpoB gene sequences and multilocus sequence typing were used for comparisons against 94 strains representing all species included in the ACB complex. Cluster analysis based on such sequences showed that all 12 strains grouped together in a distinct clade closest to Acinetobacter pittiithat was supported by bootstrap values of 99 %. Values of average nucleotide identity based on blast between the genome sequence of strain JVAP01T (NCBI accession no. LJPG00000000) and those of other species from the ACB complex were always <91.2 %, supporting the species status of the group. In addition, the metabolic characteristics of the group matched those of the ACB complex and the analysis of their protein signatures by matrix-assisted laser desorption ionization time-of-flight MS identified some specific peaks. Our results support the designation of these strains as representing a novel species, for which the name Acinetobacter dijkshoorniae sp. nov. is proposed. The type strain is JVAP01T (=CECT 9134T=LMG 29605T).

The investigation of oxacillinase/metallo-beta-lactamase genes and clonal analysis in carbapenem-resistant Klebsiella pneumoniae.

Infections due to carbapenem-resistant Klebsiella pneumoniae represent a growing problem nationally. In our study, we aimed to examine carbapenem-resistant K. pneumoniae with multiple resistance isolated in the intensive care unit of our hospital. Isolates were investigated for the presence of oxacillinase and metallo-beta lactamase genes with a view to determining the clonal relationship between the strains intensely over a short period. Strain identification was completed with conventional methods and automated identification kit. OXA-58, OXA-23, OXA-51, OXA-24 and OXA-48 and metallo-beta lactamase genes IPM, VIM, SPM, SIM, GIM and NDM-1 were investigated with PCR. For clonal relationships of carbapenem-resistant strains, the PFGE experiment was performed. While all of these carbapenem-resistant strains were positive for OXA-48, the resistant genes NDM-1, VIM, KPC, IPM, SPM, GIM, SIM, OXA-23, OXA-24, OXA-58 and OXA-51 were not observed. When molecular typing results were investigated, PFGE determined clonal distribution of three pulsotypes. However, it was observed that the strains intensified in a single clone and this was assessed as the outbreak isolate. The results of this study showed the primary enzyme responsible for carbapenem resistance in K. pneumoniae strains in our hospital is still OXA-48. To prevent the spread of carbapenem-resistant K. pneumoniae isolates, with epidemic potential, national-level monitoring and effective infection control precautions should be enforced.

Small RNA Sequencing Based Identification of MiRNAs in Daphnia magna.

Small RNA molecules are short, non-coding RNAs identified for their crucial role in post-transcriptional regulation. A well-studied example includes miRNAs (microRNAs) which have been identified in several model organisms including the freshwater flea and planktonic crustacean Daphnia. A model for epigenetic-based studies with an available genome database, the identification of miRNAs and their potential role in regulating Daphnia gene expression has only recently garnered interest. Computational-based work using Daphnia pulex, has indicated the existence of 45 miRNAs, 14 of which have been experimentally verified. To extend this study, we took a sequencing approach towards identifying miRNAs present in a small RNA library isolated from Daphnia magna. Using Perl codes designed for comparative genomic analysis, 815,699 reads were obtained from 4 million raw reads and run against a database file of known miRNA sequences. Using this approach, we have identified 205 putative mature miRNA sequences belonging to 188 distinct miRNA families. Data from this study provides critical information necessary to begin an investigation into a role for these transcripts in the epigenetic regulation of Daphnia magna.

Identification of NDM-1 in a Putatively Novel Acinetobacter Species ("NB14") Closely Related to Acinetobacter pittii.

In this study, we describe the molecular characterization of a plasmid-located blaNDM-1 harbored by an Acinetobacter clinical isolate recovered from a patient in Turkey that putatively constitutes a novel Acinetobacter species, as shown by its distinct ARDRA (amplified 16S ribosomal DNA restriction analysis) profile and molecular sequencing techniques. blaNDM-1 was carried by a conjugative plasmid widespread among non-baumannii Acinetobacter isolates, suggesting its potential for dissemination before reaching more clinically relevant Acinetobacter species.

A milk pump as a source for spreading Acinetobacter baumannii in a neonatal intensive care unit.

Acinetobacter baumannii is a Gram-negative coccobacillus that has emerged as a troublesome pathogen causing institutional outbreaks. Environmental contamination is a distinctive characteristic of this microorganism, which brings a further difficulty in infection control. During A. baumannii outbreaks in intensive care units, a common contaminated object can be found as a reservoir. Finding out this source by epidemiological investigations is of particular importance in order to develop effective interventions. We describe an outbreak of A. baumannii and the results of epidemiological investigations in a neonatal intensive care unit. The outbreak strain was isolated from the outer surface of a breastmilk pump. We have successfully controlled the outbreak by careful reviewing of our milk collection process.

[Seroprevalence of Bartonella henselae and Bartonella quintana in blood donors in Aydin province, Turkey]. / Aydin ili kan donörlerinde Bartonella henselae ve Bartonella quintana seroprevalansi

Bartonella species cause several diseases in humans such as cat stratch disease, bacillary angiomatosis, peliosis hepatis, endocarditis, Carrion disease and trench fever. Cat scratch disease and bacillary angiomatosis cases have already been reported in Turkey. Studies from our region, namely Aydin (a province located at Western Anatolia, Turkey) indicated that mean Bartonella henselae IgG seropositivity rate is 11.5% in risk groups and may reach to 26.5% in pet owners. The aim of this study was to determine the seroprevalence of B.henselae and B.quintana in healthy blood donors in our university hospital in Aydin, for estimating the transmission risk via transfusion. The study was designed as a cross-sectional epidemiological study. A total of 333 samples taken from blood donors (49 female, 284 male) who were sequentially admitted to the blood center of the university hospital, in January 2011 were included in the study. All sera were screened in terms of B.henselae and Bartonella quintana IgG antibodies by using two different indirect immunofluorescent antibody (IFA) commercial kits (Vircell, Spain; Focus, USA). Slides were examined at a final magnification of x400 on fluorescent microscope by two different assigned researchers. Fluorescent intensity was graded between 1+ to 4+, and the samples with fluorescence value of ≥ 2+ were considered as positive. The seropositivity rate of IgG antibodies to B.henselae was found as 3.3% (11/333) in blood donors. This rate was 4.1% in female, and 3.2% in male donors, showing no statistically significant difference between the genders (p= 0.668). B.henselae antibody titers were detected as 1/64 in 6 (1.8%), 1/128 in 4 (1.2%) and 1/1024 in 1 (0.3%) patient. All of the B.henselae IgG positive samples also yielded relatively low positivity for B.quintana IgG, possibly indicating cross reactivity. The fluorescence intensity for different kits used was found to be the same in all but one titer. The results reported by two researchers were found to differ only in the samples graded 1+ or below. However, the evaluation differences between the kits and the researchers did not affect the results. It was concluded that B.henselae infection might be found in the blood donors in our region, thus, a detailed questionnaire prior to blood donation might be helpful to prevent transmission of B.henselae by blood transfusion.

A newborn with pertussis accompanying nephrotic syndrome.

Pertussis or whooping cough is a vaccine-preventable disease that still remains a serious infection in neonates and young infants. The disease is particularly severe in infants less than three months old, who are often infected by their parents. Congenital nephrotic syndrome is a rare entity presenting within the first three months. It encompasses a heterogeneous group of entities with genetic, infectious and idiopathic etiologies. In this report we describe a newborn infant who presented with congenital nephrotic syndrome secondary to Bordetella pertussis infection.

[Investigation of Coxiella burnetii prevalence in women who had miscarriage and their spouses by serological and molecular methods]. / Düsük yapmis kadinlarda ve eslerinde Coxiella burnetii prevalansinin serolojik ve moleküler yöntemlerle arastirilmasi

Coxiella burnetii is the causative agent of the common zoonotic disease known as Q fever. Human infection is mostly maintained by inhalation of contaminated aerosols that originate from infected birth products, milk and urine. Sexual transmission has also been reported. In pregnant women the disease causes abortion during the first trimester, while at later stages it tends to become chronic causing low birth weight babies and premature birth. The aim of this study was to investigate the prevalence of C.burnetii in women who had miscarriages, their spouses and in a control group composed of women with normal delivery by using serological and molecular methods. A total of 89 cases (58 female, 31 male; age range: 21-64 years, mean age: 33.1 ± 7.6 years) were included in the study. Women who had abortion (n= 36) were recruited along with their husbands (n= 31), and 22 women who had normal pregnancy were accepted as controls. Blood and placental tissue samples (after abortion or normal delivery) were collected from all of the female subjects, while blood samples were collected from the males. C.burnetii IgG and IgM antibodies in the sera of patients and controls were analysed by ELISA and indirect fluorescein antibody (IFA) methods, and the presence of C.burnetii DNA was searched in whole blood and placenta samples by using polymerase chain reaction (PCR). In our study, C.burnetii Phase II IgG antibody positivity rates in women who had miscarriages, their spouses and in women with normal delivery were found as 27.8% (10/36), 38.7% (12/31) and 4.5% (1/22), respectively by ELISA, while those rates were detected as 27.8% (10/36), 41.9% (13/31) and 9.1% (2/22), respectively by IFA which was accepted as the reference method. However C.burnetii Phase I IgM, Phase I IgG and Phase II IgM antibodies were not detected in none of the subjects by both methods. The relatively high seropositivity rate in our study group (25/89; 28.1%) was thought to be associated with high rates of livestock breeding in our region. Although C.burnetii IgG seropositivity rate in in women who had miscarriages was higher than women with normal delivery, the difference was not found to be statistically significant (x2= 2.906, p= 0.088). When the results of the women with miscarriages and their spouses were evaluated together, it was detected that C.burnetii IgG antibodies were not determined in the spouses of four seropositive women (two positive with 1/64, two with 1/128 titer); titer was 1/64 in four women and their spouses and two women with 1/128 titer had spouses with 1/64 titer. The determination of high titer phase II IgG positivity in 13% (4/31) of the spouses of women who had miscarriages was of notice. All of the blood (n= 89) and placenta samples (n= 51, 29 were from aborted and 22 from normal delivered women) were negative for C.burnetii DNA by PCR. In conclusion, since livestock breeding is common in our region, in cases with recurrent abortion and premature births, women and their husbands should be screened for C.burnetii.

Detection of human bocavirus in children with upper respiratory tract infection by polymerase chain reaction.

BACKGROUND: The aim of this study was to investigate whether in children with middle ear effusions (MEE), adenoid and tonsil tissues are associated with human bocavirus (HBoV). MATERIALS AND METHODS: A total of 124 patients (56 females (45.2%) and 68 males (54.8%)) with chronic adenotonsillitis and serous otitis media under the age of 15 were recruited. Two hundered four samples (113 adenoid (55.4%), 68 tonsil (33.3%), and 23 middle ear effusion (11.3%)) were analyzed for the presence of HBoV using polymerase chain reaction (PCR). RESULTS: HBoV was detected in only 6 (4.8%) adenoid tissue samples each belonging to a different patient. CONCLUSIONS: Our findings are consistent with the results of other studies, reporting approximately 5 - 10% of the samples being positive for HBoV. To understand the detailed role of HBoV in the etiology of RTI in children, further studies would be needed.

Evaluation of resistance mechanisms and serotype and genotype distributions of macrolide-resistant strains in clinical isolates of Streptococcus pneumoniae [corrected] in Aydin, Turkey.

Macrolide resistance mechanisms in 89 Streptococcus pneumoniae strains isolated from several clinical samples between February 2007 and May 2009 were investigated. Erythromycin resistance was noted in 35 (40%) S. pneumoniae strains. In these strains, the most frequent resistance phenotype was cMLS(B) (74%), and the most frequent resistance genotype was ermB (82%). Both ermB and mefA genes were positive in 20% of macrolide-resistant strains. While no resistance to vancomycin, linezolid and telithromycin was noted in 89 S. pneumoniae strains, 12 (13%) strains were penicillin resistant, 26 (30%) strains were clindamycin resistant, 35 (40%) were azithromycin resistant, 32 (36%) strains were tetracycline resistant, and 1 (1%) strain was levofloxacin resistant. The serotype distribution of 35 macrolide-resistant S. pneumoniae strains revealed that the most frequent serotype was serogroup 19 (45%). Multidrug resistance was present in 19 (86%) of 22 strains carrying only the ermB resistance gene. No clonal dissemination was noted in the macrolide-resistant pneumococcal strains. These findings suggest that macrolide resistance rates, resistance phenotype and genotype, as well as resistant serotypes of S. pneumoniae strains should be continuously monitored in our country.

Infecções relacionadas a cateteres torácicos / Thoracic catheter-related infections

OBJETIVO: Determinar o status de colonização de uma amostra de pacientes que recebeu cateteres torácicos (CTs) e correlacionar esse status a possíveis fatores prognósticos. MÉTODOS: Estudo retrospectivo com 48 pacientes (17 mulheres e 31 homens) que receberam CTs no Departamento de Cirurgia Torácica do Hospital Universitário Adnan Menderes, localizado na cidade de Aydin, Turquia, entre dezembro de 2008 e março de 2009. Amostras de sangue para cultura foram coletadas da porção distal dos CTs e de cada um dos 48 pacientes. Procuramos por correlações entre culturas positivas e possíveis fatores prognósticos de infecção. RESULTADOS: Resultados positivos de cultura em amostras de CT ocorreram somente 3 pacientes, em sangue em 2, e nas duas amostras em outros 2. A idade avançada correlacionou-se com culturas positivas das amostras de CT e sangue (r = 0,512 e r = 0,312, respectivamente; p < 0,05), assim como o uso prolongado do CT e com culturas positivas das mesmas amostras (r = 0,347 e r = 0,372, respectivamente; p < 0,05). Houve uma correlação significativa entre o status cirúrgico dos pacientes (aqueles submetidos a cirurgias) e culturas positivas somente das amostras de CT (p < 0,05), mas a presença de malignidade inoperável correlacionou-se com o crescimento bacteriano em ambos os tipos de amostras (p < 0,05 para ambos). CONCLUSÕES: Os fatores de risco acima citados aumentam o risco de infecções. No caso de pacientes com CTs e que apresentam tais fatores de risco, é imperativo que se utilize uma profilaxia com antibióticos de amplo espectro.

OBJECTIVE: To determine the incidence of local and systemic infection in a sample of patients catheterized with thoracic catheters (TCs) and to identify the prognostic factors for catheter-related infection. METHODS: A retrospective study involving 48 patients (17 females and 31 males) catheterized with TCs between December of 2008 and March of 2009 in the Thoracic Surgery Department of the Adnan Menderes University Hospital, located in Aydin, Turkey. Blood samples for culture were collected from the distal end of each TC and from each of the 48 patients. We looked for correlations between positive culture and possible prognostic factors for catheter-related infection. RESULTS: Culture results were positive in TC samples only for 3 patients, in blood samples only for 2, and in both types of samples for another 2. Advanced age correlated significantly with positive culture in TC samples and in blood samples (r = 0.512 and r = 0.312, respectively; p < 0.05 for both), as did prolonged catheterization (r = 0.347 and r = 0.372, respectively; p < 0.05). There was a significant correlation between having undergone surgery and positive culture in TC samples only (p < 0.05). However, having an inoperable malignancy correlated with bacterial growth in blood and in TC samples alike (p < 0.05 for both). CONCLUSIONS: Risk factors, such as advanced age, prolonged catheterization, comorbidities, and inoperable malignancy, increase the risk of catheter-related infection. It is imperative that prophylaxis with broad-spectrum antibiotics be administered to patients who present with these risk factors and might be catheterized with a TC.

Prevalence of enterotoxins among Escherichia coli isolates causing bacteraemia.

The most frequent cause of bacteraemia among Gram-negative bacteria is Escherichia coli. Analysis of the genes encoding the Shigella enterotoxin 1 (ShET-1), ShET-2, enteroaggregative heat stable toxin 1 (EAST-1) toxins and AggR factor in E. coli strains causing bacteraemia revealed that set1 genes were presented significantly more frequently among quinolone-susceptible strains (P<0.0001), in phylogenetic group B2 (P=0.0004) and in biofilm strains (P=0.02). In contrast, sen genes were significantly more frequent among nalidixic acid-resistant isolates (15% vs. 6%, P=0.046) and in phylogenetic group B1 (P=0.0001). This is the first study in which ShET1, ShET2 and EAST-1 have been found in E. coli collected from blood.