Evaluating the Effect of Azole Antifungal Agents on the Stress Response and Nanomechanical Surface Properties of Ochrobactrum anthropi Aspcl2.2.

Azole antifungal molecules are broadly used as active ingredients in various products, such as pharmaceuticals and pesticides. This promotes their release into the natural environment. The detailed mechanism of their influence on the biotic components of natural ecosystems remains unexplored. Our research aimed to examine the response of Ochrobactrum anthropi AspCl2.2 to the presence of four azole antifungal agents (clotrimazole, fluconazole, climbazole, epoxiconazole). The experiments performed include analysis of the cell metabolic activity, cell membrane permeability, total glutathione level and activity of glutathione S-transferases. These studies allowed for the evaluation of the cells' oxidative stress response to the presence of azole antifungals. Moreover, changes in the nanomechanical surface properties, including adhesive and elastic features of the cells, were investigated using atomic force microscopy (AFM) and spectrophotometric methods. The results indicate that the azoles promote bacterial oxidative stress. The strongest differences were noted for the cells cultivated with fluconazole. The least toxic effect has been attributed to climbazole. AFM observations unraveled molecular details of bacterial cell texture, structure and surface nanomechanical properties. Antifungals promote the nanoscale modification of the bacterial cell wall. The results presented provided a significant insight into the strategies used by environmental bacterial cells to survive exposures to toxic azole antifungal agents.

Catheter-related Bloodstream Infections: A Root Cause Analysis in a Series of Simultaneous Ochrobactrum anthropi Infections.

OBJECTIVE: Catheter-related bloodstream infections (CRBSIs) pathogenesis is complex and multifactorial mostly due to cutaneous microorganisms migration through the catheter insertion site and catheter tip colonization. Ochrobactrum anthropi is a gram-negative bacterium belonging to the Brucellaceae and related infections are especially observed in immunocompromised patients. METHODS: Therefore, O. anthropi infection prevention and surveillance are relevant issues for healthcare system and risk management, in order to improve healthcare quality and patient safety. Four cases of anthropi-related CRBSIs occurring in immunodepressed patients under chemotherapy treatment are reported and the possible prevention and surveillance strategies are analyzed. RESULTS: In the reported cases, all infections occurred almost simultaneously in the Oncology Unit, leading to hypothesize an identical infection source. Subsequently, a clinical audit was performed in order to investigate infection origin and implement prevention and control strategies. Clinical audit allowed to identify the hand hygiene defects as the primary source of the infections, responsible for catheter flushing solution contamination. CONCLUSION: The aim of this study is to reveal how through correct root cause analysis and clinical audit, several measures could be undertaken in order to promote the prevention of the CRBSIs risk.

Antibiotic susceptibility and production of endotoxin by Ochrobactrum anthropi isolated from environment and from patients with cystic fibrosis.

The aim of this work was to compare production of endotoxin and to determine susceptibility to antibiotics in two groups of specimens-wild-type strains Ochrobactrum anthropi isolated from the environment and the strains isolated from patients with cystic fibrosis. The determination of the endotoxin produced by the test strains was carried on by using a limulus amebocyte lysate test (LAL test). Determination of ATB sensitivity was accomplished by means of a broth dilution method in a microtiter plate (MIC). No significant difference was found between the group of ochrobacters isolated from the environment and the group of ochrobacters isolated from cystic fibrosis patients. Antibiotic sensitivity testing has indicated that the resistance to tigecycline, trimethoprim/sulfamethoxazole, and gentamicin was slightly higher in strains isolated from cystic fibrosis patients in comparison with strains isolated from the environment. In general, most of the test strains were sensitive to most of the antibiotics tested. Significant resistance has been demonstrated for cefotaxime. Resistance was also found for gentamicin in strains number 4 and 7. The MIC was equal to the breakpoint for this antibiotic (8000 mg/L).

Diversity of Ochrobactrum species in food animals, antibiotic resistance phenotypes and polymorphisms in the blaOCH gene.

Twenty-six lactose non-fermenting, oxidase, urease and citrate-positive Gram-negative rods, isolated from broiler chickens, pigs and cattle at slaughter, were subjected to the matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and 16S rDNA sequencing for identification. Susceptibility to 14 antimicrobials was determined by the disc diffusion method. Ochrobactrum isolates resistant to third-generation cephalosporins were PCR-screened for the presence of the Ochrobactrum anthropi ampC gene (blaOCH). A 547-bp internal segment of blaOCH in the Ochrobactrum spp isolates was amplified with a newly designed primer set, and a phylogenetic reconstruction based on the complete amino acid sequence of blaOCH obtained from nine Ochrobactrum strains in our collection and 20 O. anthropi available in the GenBank was undertaken. All the Ochrobactrum isolates were resistant to the expanded-spectrum beta-lactams and streptomycin. None of the isolates was resistant to imipenem while 41.7% to 50.0% of them were resistant to fluoroquinolones. The blaOCH gene was detected in 16 (66.7%) and 20 (83.3%) of the 24 Ochrobactrum isolates (O. intermedium/O. tritici species), using primers designed for O. anthropi and the newly designed primer set, respectively. Six blaOCH variants grouped into two divergent clusters were identified. This is the first report of the complete nucleotide sequence of the blaOCH gene in non-antropi Ochrobactrum species.

Ochrobactrum anthropi bacteremia in a preterm infant with cystic fibrosis.

Ochrobactrum anthropi infection in newborn patients is rare, and the treatment is challenging because of its widespread and unpredictable resistance to antimicrobial agents and discrepancies between in vitro susceptibility and in vivo efficacy. We report the clinical and microbiological characteristics of Ochrobactrum anthropi bacteremia in a preterm patient.

Ochrobactrum anthropi bacteremia in a preterm infant with cystic fibrosis

Ochrobactrum anthropi infection in newborn patients is rare, and the treatment is challenging because of its widespread and unpredictable resistance to antimicrobial agents and discrepancies between in vitro susceptibility and in vivo efficacy. We report the clinical and microbiological characteristics of Ochrobactrum anthropi bacteremia in a preterm patient.

Molecular cloning and characterization of a newly isolated pyrethroid-degrading esterase gene from a genomic library of Ochrobactrum anthropi YZ-1.

A novel pyrethroid-degrading esterase gene pytY was isolated from the genomic library of Ochrobactrum anthropi YZ-1. It possesses an open reading frame (ORF) of 897 bp. Blast search showed that its deduced amino acid sequence shares moderate identities (30% to 46%) with most homologous esterases. Phylogenetic analysis revealed that PytY is a member of the esterase VI family. pytY showed very low sequence similarity compared with reported pyrethroid-degrading genes. PytY was expressed, purified, and characterized. Enzyme assay revealed that PytY is a broad-spectrum degrading enzyme that can degrade various pyrethroids. It is a new pyrethroid-degrading gene and enriches genetic resource. Kinetic constants of Km and Vmax were 2.34 mmol·L(-1) and 56.33 nmol min(-1), respectively, with lambda-cyhalothrin as substrate. PytY displayed good degrading ability and stability over a broad range of temperature and pH. The optimal temperature and pH were of 35°C and 7.5. No cofactors were required for enzyme activity. The results highlighted the potential use of PytY in the elimination of pyrethroid residuals from contaminated environments.

Ochrobactrum anthropi: a rare cause of pneumonia.

Ochrobactrum anthropi, a Gram-negative bacillus, is an unusual human pathogen. It has been implicated primarily in catheter-related bloodstream infections. Sporadic cases of infection at other body sites have been reported. Pneumonia, however, is an exceedingly rare clinical manifestation; only one case has been reported in the medical literature so far. We present another case of lower respiratory tract infection secondary to O. anthropi in a patient who was critically ill, but recovered with a favorable outcome. We have provided an overview of clinical manifestations, diagnosis, and treatment of infections due to this rare microorganism.

An opportunistic pathogen in a peritoneal dialysis patient: Ochrobactrum anthropi.

The authors report a case of chronic peritoneal dialysis-related peritonitis from Ochrobactrum anthropi. O. anthropi is an emerging pathogen in immunocompromised patients. O. anthropi-related peritonitis in peritoneal dialysis patients has rarely been reported. To the authors' knowledge, no pediatric case of O. anthropi peritonitis has been reported to date in the literature.

Isolation and characterization of Ochrobactrum anthropi and Ochrobactrum pecoris from caecal content of commercial turkeys.

Two Gram negative, micro-aerophilic, non-motile and non-spore-forming coccoid bacteria were isolated from female turkey caecal samples collected from a slaughterhouse. The biochemical reaction profiles (API 20 E and API 20 NE) typed both strains as Ochrobactrum anthropi. On the basis of 16S rRNA gene and recA gene sequence similarities the strains were identified as O. anthropi and Ochrobactrum pecoris, respectively. Both strains were highly resistant against beta-lactam antibiotics, chloramphenicol and sulphonamides but variable in susceptibility to ciprofloxacin, gentamicin and tetracycline. This is the first time that Ochrobactrum species were isolated from an avian host, i.e. turkey.

Improvement of glyphosate resistance through concurrent mutations in three amino acids of the Ochrobactrum 5-enopyruvylshikimate-3-phosphate synthase.

A mutant of 5-enopyruvylshikimate-3-phosphate synthase from Ochrobactrum anthropi was identified after four rounds of DNA shuffling and screening. Its ability to restore the growth of the mutant ER2799 cell on an M9 minimal medium containing 300 mM glyphosate led to its identification. The mutant had mutations in seven amino acids: E145G, N163H, N267S, P318R, M377V, M425T, and P438L. Among these mutations, N267S, P318R, and M425T have never been previously reported as important residues for glyphosate resistance. However, in the present study they were found by site-directed mutagenesis to collectively contribute to the improvement of glyphosate tolerance. Kinetic analyses of these three mutants demonstrated that the effectiveness of these three individual amino acid alterations on glyphosate tolerance was in the order P318R > M425T > N267S. The results of the kinetic analyses combined with a three-dimensional structure modeling of the location of P318R and M425T demonstrate that the lower hemisphere's upper surface is possibly another important region for glyphosate resistance. Furthermore, the transgenic Arabidopsis was obtained to confirm the potential of the mutant in developing glyphosate-resistant crops.

Biliary sepsis caused by Ochrobactrum anthropi.

Ochrobactrum anthropi is an emerging pathogen in immunocompromised patients, with the majority of human cases being central venous catheter-related infections. In contrast, O. anthropi-related biliary sepsis is much rare. Herein we report the clinical and microbiological characteristics of O. anthropi-related biliary sepsis in order to increase awareness of the potential role of O. anthropi in this infection. Further extensive epidemiologic studies should be carried out to ascertain the etiologic association between O. anthropi and biliary sepsis and to identify potential hosts and routes of transmission.

Microbial conversion of 5-sulfoisophthalic acid into 5-hydroxyisophthalic acid by Ochrobactrum anthropi S9.

5-Hydroxyisophthalic acid-producing microorganisms were isolated from enrichment cultures using 5-sulfoisophthalic acid as a sulfur source. One bacterium, Ochrobactrum anthropi S9, had the highest 5-sulfoisophthalic acid-degrading activity, and stoichiometrically formed 5-hydroxyisophthalic acid, a raw material for polymer synthesis. Under optimum culture conditions, 1.3 mM 5-hydroxyisophthalic acid accumulated in the medium by 60 h. The addition of Na(2)SO(4), L: -methionine or L: -cysteine at 2 mM inhibited the conversion of 5-sulfoisophthalic acid. O. anthropi S9 cells converted 5-sulfoisophthalic acid, benzenesulfonic acid, 3-sulfobenzoic acid, 4-aminobenzenesulfonic acid, naphthalene-1-sulfonic acid and naphthalene-2-sulfonic acid into the corresponding hydroxylated compounds.

Novel denitrifying bacterium Ochrobactrum anthropi YD50.2 tolerates high levels of reactive nitrogen oxides.

Most studies of bacterial denitrification have used nitrate (NO3-) as the first electron acceptor, whereas relatively less is understood about nitrite (NO2-) denitrification. We isolated novel bacteria that proliferated in the presence of high levels of NO2- (72 mM). Strain YD50.2, among several isolates, was taxonomically positioned within the alpha subclass of Proteobacteria and identified as Ochrobactrum anthropi YD50.2. This strain denitrified NO2-, as well as NO3-. The gene clusters for denitrification (nar, nir, nor, and nos) were cloned from O. anthropi YD50.2, in which the nir and nor operons were linked. We confirmed that nirK in the nir-nor operon produced a functional NO2- reductase containing copper that was involved in bacterial NO2- reduction. The strain denitrified up to 40 mM NO2- to dinitrogen under anaerobic conditions in which other denitrifiers or NO3- reducers such as Pseudomonas aeruginosa and Ralstonia eutropha and nitrate-respiring Escherichia coli neither proliferated nor reduced NO2-. Under nondenitrifying aerobic conditions, O. anthropi YD50.2 and its type strain ATCC 49188(T) proliferated even in the presence of higher levels of NO2- (100 mM), and both were considerably more resistant to acidic NO2- than were the other strains noted above. These results indicated that O. anthropi YD50.2 is a novel denitrifier that has evolved reactive nitrogen oxide tolerance mechanisms.

Effect of glutaraldehyde treatment on stability of permeabilized Ochrobactrum anthropi SY509 in nitrate removal.

For practical application, the stability of permeabilized Ochrobactrum anthropi SY509 needs to be increased, as its half-life of enzymatic denitrification is only 90 days. As the cells become viable after permeabilization treatment, this can cause decreased activity in a long-term operation and induce breakage of the immobilization matrix. However, the organic solvent concentration causing zero cell viability was 50%, which is too high for industrial application. Thus, wholecell immobilization using glutaraldehyde was performed, and 0.1% (v/v) glutaraldehyde was determined as the optimum concentration to maintain activity and increase the half-life. It was also found that 0.1% (v/v) glutaraldehyde reacted with 41.9% of the total amine residues on the surface of the cells during the treatment. As a result, the half-life of the permeabilized cells was increased from 90 to 210 days by glutaraldehyde treatment after permeabilization, and no cell viability was detected.

An epidemic of chronic pseudophakic endophthalmitis due to Ochrobactrum anthropi: clinical findings and managements of nine consecutive cases.

PURPOSE: To report an epidemic of O. anthropi pseudophakic endophthalmitis. METHODS: The medical records of nine patients with culture-proven O. anthropi endophthalmitis were reviewed. RESULTS: The presenting features were compatible to chronic endophthalmitis. Two patients showed coinfections with P. acnes. Antibiotics sensitivity test revealed susceptibility to quinolones. Pars plana vitrectomy (PPV) with partial capsulectomy (PC) cured infections in seven patients without coinfection of P. acnes. Final visual acuity was 20/40 or better in five patients. CONCLUSIONS: O. anthropi should be considered in cases with chronic pseudophakic endophthalmitis. PPV with PC should be the initial therapeutic option for O. anthropi endophthalmitis.

[Ochrobactrum anthropi bacteremia developed after cholangiopancreatography]. / Olgu sunumu: kolanjiopankreatografi sonrasinda gelisen Ochrobactrum anthropi bakteriyemisi.

Ochrobactrum anthropi (formerly Achromobacter spp.) is an aerobic, motile, oxidase positive and lactose negative gram negative bacillus which is widely distributed in the environment and water sources. In recent publications, O. anthropi has an increasing importance as a nosocomial infection agent. The aim of this report was to present a case of O. anthropi bacteremia developed after endoscopic retrograde cholangiopancreatography (ERCP). A 89-year old female patient presented with high fever one day after ERCP performed due to klatskin tumour. O. anthropi had been grown in blood culture (BacT/ALERT 3D, bioMérieux, Durham, USA), and the isolate was identified by automatized system (VITEK, bioMerieux, Marcy l'Etoile, France). Since there was no clinical response to empirical ceftriaxone therapy, it was switched to meropenem, which was found effective by VITEK antibiotic susceptibility detection system. The patient was treated successfully with meropenem therapy (3 x 1 gr/day, 10 days). As a result, in case of suspected post-ERCP bacteremia, unconventional microorganisms such as O. anthropi should be taken into consideration.