Ochrobactrum Anthropi Research Articles

Synthetic communities derived from the core endophytic microbiome of hyperaccumulators and their role in cadmium phytoremediation.

Although numerous endophytic bacteria have been isolated and characterized from cadmium (Cd) hyperaccumulators, the contribution and potential application of the core endophytic microbiomes on facilitating phytoremediation were still lack of intensive recognition. Therefore, a 2-year field sampling in different location were firstly conducted to identify the unique core microbiome in Cd hyperaccumulators, among which the representative cultivable bacteria of different genera were then selected to construct synthetic communities (SynComs). Finally, the effects and mechanisms of the optimized SynCom in regulating Cd accumulation in different ecotypes of Sedum alfredii were studied to declare the potential application of the bacterial agents based on core microbiome. Through an innovative network analysis workflow, 97 core bacterial taxa unique to hyperaccumulator Sedum was identified based on a 2-year field 16S rRNA sequencing data. A SynCom comprising 13 selected strains belonging to 6 different genera was then constructed. Under the combined selection pressure of the plant and Cd contamination, Alcaligenes sp. exhibited antagonistic relationships with other genera and plant Cd concentration. Five representative strains of the other five genera were further conducted genome resequencing and developed six SynComs, whose effects on Cd phytoremediation were compared with single strains by hydroponic experiments. The results showed that SynCom-NS comprising four strains (including Leifsonia shinshuensis, Novosphingobium lindaniclasticum, Ochrobactrum anthropi, and Pseudomonas izuensis) had the greatest potential to enhance Cd phytoremediation. After inoculation with SynCom-NS, genes related to Cd transport, antioxidative defense, and phytohormone signaling pathways were significantly upregulated in both ecotypes of S. alfredii, so as to promote plant growth, Cd uptake, and translocation. In this study, we designed an innovative network analysis workflow to identify the core endophytic microbiome in hyperaccumulator. Based on the cultivable core bacteria, an optimized SynCom-NS was constructed and verified to have great potential in enhancing phytoremediation. This work not only provided a framework for identifying core microbiomes associated with specific features but also paved the way for the construction of functional synthetic communities derived from core microbiomes to develop high efficient agricultural agents. Video Abstract.

<i>Ochrobactrum anthropi</i>: a rare case of endocarditis

Ochrobactrum anthropi is an aerobic Gram-negative bacillus, formerly known as “Achromobacter group Vd”. It is increasingly recognized as a potentially problematic, opportunistic, and nosocomial pathogen. Most cases of human diseases due to O. anthropi are associated with central venous catheter line infection; few case reports about infective endocarditis, pancreatic abscess, puncture wound osteochondritis, endophthalmitis, urinary tract infection, meningitis, pelvic abscess, and osteomyelitis are present in the literature. Among the previously stated infections it can cause, infective endocarditis is very rare; only four cases have been described in the literature. Here, we report the case of an immunocompromised man who developed native valve endocarditis with septic cerebral embolization due to O. anthropi.

Insights into the microbiota of raw milk from seven breeds animals distributing in Xinjiang China.

Owing to its high nutritional content, raw milk contains a rich microbiota. Thus, to study microorganisms present in raw milk available in Xinjiang China, 142 raw milk samples from seven animal breeds (cow, sheep, goat, donkey, horse, camel, and yak) and four regions (Hami, Tarbagatay, Kashgar, and Ili) were analyzed by high-throughput DNA sequencing. These microorganisms were characterized by 10 dominant phyla. Proteobacteria (68.33%) was the major phylum, followed by Firmicutes (18.80%) and Thermi (3.16%). Horse milk contained more Bacteroidetes, sheep milk contained more Gammaproteobacteria, and donkey milk contained more unclassified sequences. Camel and donkey milk contained the highest and lowest bacterial diversity compared with that contained by the remaining milk samples, respectively. Additionally, spoilage microorganisms, including Chryseobacterium, Propionibacterium, and Flavobacterium, and pathogenic bacteria, including Ochrobactrum anthropi and Sphingomonas, were more prevalent in horse and yak milk, whereas probiotic lactic acid bacteria (LAB), such as Leuconostoc, Lactococcus, or Lactobacillus, were more prevalent in goat, donkey, and camel milk. Furthermore, Moraxella was abundantly present in goat, camel, and yak milk, Acinetobacter was more abundant in camel milk, and Pseudomonas was relatively abundant in sheep and donkey milk. Overall, specific harmful microorganisms and probiotic lactic acid bacteria were found in the raw milk samples obtained from different animals, which provided a basis for preventing and controlling the growth of harmful bacteria, as well as investigating probiotic resources in raw milk.

Detoxification of ars genotypes by arsenite-oxidizing bacteria through arsenic biotransformation.

The detoxification process of transforming arsenite (As(III)) to arsenate (As(V)) through bacterial oxidation presents a potent approach for bioremediation of arsenic-polluted soils in abandoned mines. In this study, twelve indigenous arsenic-oxidizing bacteria (AOB) were isolated from arsenic-contaminated soils. Among these, Paenibacillus xylanexedens EBC-SK As2 (MF928871) and Ochrobactrum anthropi EBC-SK As11 (MF928880) were identified as the most effective arsenic-oxidizing isolates. Evaluations for bacterial arsenic resistance demonstrated that P. xylanexedens EBC-SK As2 (MF928871) could resist As(III) up to 40 mM, while O. anthropi EBC-SK As11 (MF928880) could resist As(III) up to 25 mM. From these bacterial strains, genotypes of arsenic resistance system (ars) were detected, encompassing ars leader genes (arsR and arsD), membrane genes (arsB and arsJ), and aox genes known to be crucial for arsenic detoxification. These ars genotypes in the isolated AOBs might play an instrumental role in arsenic-contaminated soils with potential to reduce arsenic contamination.

The evolution of reduced facilitation in a four-species bacterial community

Abstract Microbial evolution is typically studied in monocultures or in communities of competing species. But microbes do not always compete and how positive inter-species interactions drive evolution is less clear: Initially facilitative communities may either evolve increased mutualism, increased reliance on certain species according to the Black Queen Hypothesis (BQH), or weaker interactions and resource specialization. To distinguish between these outcomes, we evolved four species for 44 weeks either alone or together in a toxic pollutant. These species initially facilitated each other, promoting each other’s survival and pollutant degradation. After evolution, two species (Microbacterium liquefaciens and Ochrobactrum anthropi) that initially relied fully on others to survive continued to do so, with no evidence for increased mutualism. Instead, Agrobacterium tumefaciens and Comamonas testosteroni (Ct) whose ancestors interacted positively, evolved in community to interact more neutrally and grew less well than when they had evolved alone, suggesting that the community limited their adaptation. We detected several gene loss events in Ct when evolving with others, but these events did not increase its reliance on other species, contrary to expectations under the BQH. We hypothesize instead that these gene loss events are a consequence of resource specialization. Finally, co-evolved communities degraded the pollutant worse than their ancestors. Together, our results support the evolution of weakened interactions and resource specialization, similar to what has been observed in competitive communities.

Genome sequences of four bacterial strains isolated from organofluorine enrichment cultures.

Because fluorinated organic compounds are broadly used and highly persistent, microbes isolated from wastewater may be able to degrade these contaminants. Here, we report the genome sequences of Flavobacterium sp. str. WV_118_3, Nocardioides sp. str. WV_118_6, Ochrobactrum anthropi str. WV_118_8, and Sphingomonas sp. str. VL_57B, isolated from wastewater.

Evaluation of a Multilocus Variable-Number Tandem-Repeat Analysis Scheme for Typing Ochrobactrum anthropi.

Ochrobactrum anthropi (O. anthropi) is found in water, soil, plants and animals. Even though it has low virulence, it has increasingly been found to cause a number of infectious diseases in people with low immunity. The identification of O. anthropi mainly uses biochemical methods, such as the API 20NE or Vitek-2. The typing studies of O. anthropi have mainly utilized PFGE, rep-PCR, AFLP, 16s rDNA sequencing, RecA-PCR RFLP, and MALDI-TOF MS. This study aims to evaluate the polymorphisms of variable-number tandem-repeats (VNTRs) within genomic DNA of O. anthropi strains. The tandem repeats (TRs) in genomic DNA are discovered using Tandem Repeat Finder software (version 4.09). Twelve different VNTRs are designated and assigned to the nomenclature. The primers for PCR of 12 loci are designed. The PCR product size is converted to the number of tandem repeats in every locus. The relatedness of 65 O. anthropi strains from geographically different countries are analyzed by means of 12-variable-number tandem-repeat analysis(MLVA-12). A total of 51 different genotypes are found in 65 O. anthropi strains. These strains, which were collected from the same environmental samples, hospitals, and countries, are clustered within the same or closely genotypes. The MLVA-12 assay has a good discriminatory power for species determination, typing of O. anthropi, and inferring the origin of bacteria.

Ochrobactrum Bacterial Mediated pH Dependent Synthesis of Silver Oxide Nanoparticles

Green synthesis of nanoparticles from bacterial origin has become popular due to the advantages associated with it. Ochrobacrtum species supernatant of various pH (4, 7 and 10) was subjected to a filtered 1.0 mM AgNO3 solution, and the mixture was incubated at 37 ℃ for 48 h. This was done to reduce silver ions into elemental silver to form nanoparticles. Nanoparticles were harvested by centrifugation and were characterized using various analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDX), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). Crystallographic studies revealed that the synthesized AgNPs were of face centered cubic crystalline phase. Silver nanoparticles with the average sizes of 55, 41 and 32 nm were obtained for Ochrobactrum anthropi silver nanoparticles synthesized at pH 4, 7 and 10 (OA4, OA7 and OA10) respectively. Ochrobactrum oryzae AgNPs synthesized at pH 4, 7 and 10 (OO4, OO7 and OO10) were 55, 37 and 43 nm respectively. A statistically significant particle size distribution was noted for both OA and OO AgNPs. Elemental analysis showed main elements to be C, O, Cl and Ag with Ag dominating. The bigger sizes of AgNPs produced under acidic conditions attributed to their ability to survive high temperatures up to 600 ℃.

Ochrobactrum anthropi infection following corneal transplantation -a case report and review of literature

BackgroundOchrobactrum anthropi is widely distributed and primarily infects patients with compromised immune functions . Historically, O. anthropi has been considered to possess low toxicity and pathogenicity; however, recent studies suggest that it may in fact cause severe purulent infections. In this case study, we examine a case of O. anthropi infection following corneal transplantation, exploring the occurrence and outcomes of such post-operative infections.Case presentationA retrospective analysis of cases involved examinations, genetic testing for diagnosis, and subsequent treatment. In patients undergoing partial penetrating keratoplasty with a fungal corneal ulcer perforation, anterior chamber exudation and purulence were observed post-surgery. Despite antifungal treatment, genetic testing of the anterior chamber fluid and purulent material confirmed O. anthropi infection. The use of antimicrobial treatment specifically targeting O. anthropi was found to be effective in treating the infection.ConclusionInflammatory reactions following corneal transplantation should be should be monitored for the presence of other infections. Genetic testing has significant implications for clinical diagnosis and treatment.

Aerobic Vaginal Microflora in Gestational and Non-Gestational Bitches (Canis lupus familiaris).

The vaginal tract comprises commensal microorganisms, which play an essential role in the health of the reproductive tract. Any dysbiosis in the vaginal microenvironment may lead to severe urinary tract infections or even infertility. This study aimed to evaluate the aerobic bacterial flora isolated from vaginal samples from 100 lactating bitches in the antepartum period (n = 3), postpartum period (n = 80), and with Lactatio sine graviditate (n = 17). Before vaginal swabs, all the bitches went through a gynecology consult, along with milk and blood sampling. Standard microbiological techniques were used for bacterial isolation. Among the 100 vaginal samples analyzed, 82% had a positive microbiological outcome, while 18% were negative. The microbiologic profile listed 17 different genera. The main isolated bacterial families were Micrococcaceae, Staphylococcaceae, Morganellaceae, Bacillaceae, and Rhizobiaceae. At the same time, strains like Agrobacterium radiobacter, Ochrobactrum anthropi, Chromobacterium violaceum, Burkholderia mallei, Bacillus pumllus, or Staphylococcus xylosus were isolated for the first time from the vaginal secretion of lactating bitches. The microbiological data demonstrates that lactating bitches' vaginal discharge is heterogeneous and may be affected by coitus, sampling season, age, and reproductive status.

Identification of <i>Brucella (Ochrobactrum) anthropi</i> by MALDI-TOF MS from blood: a case report

This case report describes the identification of Ochrobactrum anthropi (O.a.), from a positive blood culture using MALDI-TOF spectrometry system. According to the information availed this is the first case in AORN Sant’Anna and San Sebastiano, Caserta, Campania, Italy. This microbe is moderately pathogenic and hazardous, with the potential to cause hospital-acquired infections. It is recommended that it be included in hospital “germ alerts”.

Triple Gram-negative bacterial endophthalmitis following intravitreal injection

PurposeTo describe a puzzling case of endophthalmitis caused by three unusual bacteria after intravitreal injection, its outcome, and underlying questions.FindingsA 70-year-old female patient was diagnosed with acute endophthalmitis following intravitreal aflibercept injection for age-related macular degeneration. A standard tap and inject procedure was performed. Microbiological analyses on the anterior chamber and vitreous samples yielded the presence of three non-fermenting Gram-negative rods: Pseudomonas stutzeri, Stenotrophomonas maltophilia, and Ochrobactrum anthropi. The outcome was favorable after intravitreal injections of vancomycin and ceftazidime, with an almost complete recovery of the visual acuity to its baseline level. No potential source of infection was identified.ConclusionEndophthalmitis following intravitreal injection can be caused by a wide variety of bacteria, including some rare Gram-negative species. They can sometimes co-exist in a single patient, but their virulence may vary greatly. Due to the variable antibiotic susceptibility and frequent multiresistance associated with non-fermenting Gram-negative rods, a prompt microbiological approach is required. Favorable outcome can be achieved with standard management.

“Index Case of Multiresistant Ochrobactrum Anthropi in an Immunocompetent Postpartum Female with Posterior Reversible Encephalopathy Syndrome: A Unique Case at a Tertiary Care Centre in India”

Ochrobactrum anthropi, an emerging nosocomial pathogen associated with medical devices, presents a distinct challenge in healthcare. While prevalent in patients with invasive devices, such as central venous catheters, its occurrence in hemodialysis (HD) patients is rarely reported. This study details a case of O. anthropi bacteremia-induced septic shock in an immunocompetent, non-diabetic, post-LSCS-postpartum female undergoing intermittent dialysis at AIIMS Rishikesh, a tertiary care center in Uttarakhand, India. In addition to the clinical case, we provide a concise review of O. anthropi infections in HD patients, emphasizing the need for rapid pathogen identification, susceptibility testing, and tailored antimicrobial therapy for favorable outcomes.

Etiologic features of nosocomial sinusitis

To evaluate the qualitative and quantitative composition of the causative agents of nosocomial sinusitis and their sensitivity to antibacterial chemotherapy drugs in modern conditions. During the period 2022-2023, we selected 45 patients from 6 ICU based on a multidisciplinary hospital and 11 patients from the ICU based on an infectious profile hospital, who were diagnosed with nosocomial sinusitis based on anamnesis, clinical picture, and computed tomography results. The qualitative and quantitative composition of microorganisms in the discharge obtained during therapeutic and diagnostic puncture of the maxillary sinuses in all patients was studied. According to the results it was revealed that in the multidisciplinary hospital the following microorganisms were the most frequently detected in patients with nosocomial sinusitis: Klebsiella pneumoniae, Acinetobacter baumannii, Proteus mirabilis, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Staphylococcus haemolyticus, Enterococcus faecium, Enterococcus faecalis, Ochrobactrum anthropi. In patients with nosocomial sinusitis in the infectious diseases hospital the most frequently isolated were Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Proteus mirabilis. Fungal microorganisms were isolated much less frequently than bacterial microorganisms in both hospitals and were represented only by Candida albicans. In the multiprofile hospital the isolated strains of bacterial microorganisms were characterized by multidrug resistance in 89% of cases, and in the infectious diseases hospital - in 91% of cases. In the treatment of patients with nosocomial sinusitis, it is necessary to adjust empirical antibiotic therapy based on individual results of a bacteriological study. In case of ineffectiveness of antibacterial therapy, it is possible to use personalized biotherapy with virulent bacteriophage preparations in addition to prescribed antibacterial chemotherapy drugs, which makes it possible to enhance the antimicrobial effect of the therapy due to the additive action of drugs of two groups.

Development and evaluation of a triplex droplet digital PCR method for differentiation of M. tuberculosis, M. bovis and BCG.

Tuberculosis, caused by Mycobacterium tuberculosis complex (MTBC), remains a global health concern in both human and animals. However, the absence of rapid, accurate, and highly sensitive detection methods to differentiate the major pathogens of MTBC, including M. tuberculosis, M. bovis, and BCG, poses a potential challenge. In this study, we have established a triplex droplet digital polymerase chain reaction (ddPCR) method employing three types of probe fluorophores, with targets M. tuberculosis (targeting CFP-10-ESAT-6 gene of RD1 and Rv0222 genes of RD4), M. bovis (targeting CFP-10-ESATs-6 gene of RD1), and BCG (targeting Rv3871 and Rv3879c genes of ΔRD1), respectively. Based on optimization of annealing temperature, sensitivity and repeatability, this method demonstrates a lower limit of detection (LOD) as 3.08 copies/reaction for M. tuberculosis, 4.47 copies/reaction for M. bovis and 3.59 copies/reaction for BCG, without cross-reaction to Mannheimia haemolytica, Mycoplasma bovis, Haemophilus parasuis, Escherichia coli, Pasteurella multocida, Ochrobactrum anthropi, Salmonella choleraesuis, Brucella melitensis, and Staphylococcus aureus, and showed repeatability with coefficients of variation (CV) lower than 10%. The method exhibits strong milk sample tolerance, the LOD of detecting in spike milk was 5 × 103 CFU/mL, which sensitivity is ten times higher than the triplex qPCR. 60 clinical DNA samples, including 20 milk, 20 tissue and 20 swab samples, were kept in China Animal Health and Epidemiology Center were tested by the triplex ddPCR and triplex qPCR. The triplex ddPCR presented a higher sensitivity (11.67%, 7/60) than that of the triplex qPCR method (8.33%, 5/60). The positive rates of M. tuberculosis, M. bovis, and BCG were 1.67, 10, and 0% by triplex ddPCR, and 1.67, 6.67, and 0% by triplex qPCR, with coincidence rates of 100, 96.7, and 100%, respectively. Our data demonstrate that the established triplex ddPCR method is a sensitive, specific and rapid method for differentiation and identification of M. tuberculosis, M. bovis, and BCG.

A-289 Emergence of Unusual Non-Fermentative Gram-Negative Bacilli Associated to COVID-19 Period at Brazilian Hospitals

Abstract Background Since the global pandemic of coronavirus disease (COVID-19), some studies have reported on the emergence of opportunistic nosocomial pathogens associated with co-infection on the outcome of COVID-19 patients. The aim of this study was to describe the increase of six unusual species of Non-fermentative Gram-negative bacilli (NF-GNB) clinical isolates recovered from inpatients in several Brazilian hospitals comparing pre-Covid-19 (January 2018 to December 2019) period vs Covid-19 (January 2020 to December 2021) period. Methods This study design was a retrospective, observational analysis based on microbiological data of emergent NF-GNB isolates, detected in several Brazilian tertiary hospitals. The bacterial identification was performed by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF/MS) and the susceptibility of antibiotics was determined using disk diffusion method. Results During the 48 months period, a total of 1665 (2018; 349), (2019; 351), (2020; 485), (2021; 480) emergent NF-GNB isolated from blood (n = 744), respiratory tract (n = 239), skin and soft tissue (n = 264); urine (n = 119), catheter (n = 101), fluid and secretions (n = 113), Cerebrospinal fluid (n = 12) and others (n = 73) were analyzed. The frequency of NF-BGN according to species level identification was Stenotrophomonas maltophilia (1040; 62.5%), Burkholderia cepacea complex (457; 27.4%), Elizabethkingia meningoseptica (64; 3.8%), Elizabethkingia miricola (31; 1.8%), Ochrobactrum anthropi (69; 4.1%) and Ochrobactrum intermedium (4; 0.2%). The prevalence of these NF-BGN detected in pre-Covid-19 period (2018–2019) and Covid-19 period (2020–2021) were 42% and 58%, respectively. The incidence of Stenotrophomonas maltophilia, Burkholderia cepacea complex, Elizabethkingia spp. and Ochrobactrum spp. infection was (47.7% and 52.3%), (42.9% and 57.1%), (43.2% and 56.8%) and (50.7% and 49.3%) among female and man patients, respectively. For Stenotrophomonas maltophilia, Burkholderia cepacea complex and Ochrobactrum spp. the main age range was over 60 years (44.5%, 44.9% and 42.5%) while for Elizabethkingia spp. the main age range was 0–10 years of age with 42.5% of cases in the pre-COVID-19 period and over 60 years old with 43.9% in the COVID-19 period. Compared the two periods (2018–2019 vs 2020–2021) for Stenotrophomonas maltophilia the resistance rate to levofloxacin and sulfamethoxazole-trimethoprim was (3.9% vs 4.6%) and (4% vs 4.2%), respectively. Conclusion Our data point to a scenario wherein the presence of opportunistic pathogens may have been intensified by the covid-19 pandemic. Further studies should be carried out to clarify these findings.

Enhanced petroleum removal with a novel biosurfactant producer consortium isolated from drilling cuttings of offshore Akçakoca-5 in the Black Sea

Staphylococcus capitis, Achromobacter marplatensis (dominant strain), Enterobacter cloacae, Ochrobactrum anthropi, Bacillus velezensis, and Bacillus subtilis strains were isolated from drilling cutting samples. The potent biosurfactant-producing strains: S. capitis (A) &A. marplatensis (B) and non-biosurfactant-producing strains: E. cloacae (C) &O. anthropi (G) strains were combined (1:1) as AB, AC, AG, BC, BG, CG. The degradation efficiency of consortium AB was 90%, while that of consortia AC, BG and CG were 85%. Biosurfactant-producing strains belong to potent consortium AB facilitate petroleum uptake and biodegradation by increasing the solubility and surface area of substrate through emulsification activity. The physiological conditions of petroleum removal (92.5%) by potent consortium AB were optimized as: 1 g/L yeast extract, 1% petroleum, 3% NaCl at pH:7.0, 30 °C, 150 rpm for 7 days. GC/MS analysis revealed that the consortium AB not only degraded the short- and medium-chain n-alkane fractions, but also removed the long-chain n-alkanes. The biosurfactant produced (0.5 g/L) by potent consortium AB was purified by silica gel 60 chromatography, further characterized by its lipopeptide structure with TLC, FT-IR, and SEM analyses. A new halotolerant consortium AB will make a significant contribution to MEOR applications in marine ecosystem.

Biocontrol adeptness of bacterial endophytes antagonistic to Colletotrichum spp. causing Colletotrichum leaf disease in rubber (Hevea brasiliensis) and harnessing its plant growth-promoting traits

Colletotrichum Leaf Disease (CLD) is one of the major leaf diseases which significantly affect growth and yield of natural rubber (NR). Development of eco-friendly disease management strategies is the need of the hour as various commercial fungicides are banned due to their detrimental effect on environment. The present study characterized antagonistic activities and plant growth promoting properties of five bacterial endophytes, isolated from rubber leaves and roots, against Colletotrichum acutatum and C. gloeosporioides, causing CLD in rubber. In the dual culture test, Bacillus sp. and Stenotrophomonas sp. showed 62 and 60 per cent inhibition of radial growth (PIRG). With the culture filtrate, Stenotrophomonas sp. (RLR1), Bacillus sp. (RRF1), B. subtilis (RLF1), Ochrobactrum anthropi (RLF3), and Burkholderia lata (RLF15) recorded suppression of growth up to 100%. These endophytic bacterial strains were identified based on biochemical characteristics and through 16S rRNA gene sequencing. The isolates were also tested for twenty five plant growth promoting traits. All five isolates responded positively for cellulase production, siderophore production, citrate utilization, and oxidase production. However, all five strains responded negatively to chitinase, urease, phosphate solubilisation, hydrogen sulphide production, and fluorescent pigment production. These results confirmed that the five identified bacterial isolates possessing growth-promoting characteristics have the potential to be used as biocontrol agents against Colletotrichum spp., a major devastating pathogen of rubber.

A Rare Case of Bacteremia caused by Ochrobactrum anthropi in Patient with Chronic Kidney Failure Treated by Hemodialysis

Ochrobactrum anthropi, previously known as "Achromobacter group Vd", is a gram-negative, non-lactose-fermenting, obligate aerobic, indole-negative, oxidase-positive, urease-positive, motile bacillus. In recent years, it has emerged as a nosocomial infection agent especially in central venous catheters in both immunosuppressed and immunocompromised individuals. In this case report, a 56-year-old female patient who underwent dialysis for two days a week due to chronic kidney failure and had O. anthropi isolated in blood culture samples taken after fever increased is presented. In conclusion, it should be kept in mind that unusual microorganisms such as catheter-related O. anthropi may appear as causative agents in patients undergoing dialysis due to renal failure.

Immune evasion through Toll-like receptor 4: The role of the core oligosaccharides from α2-Proteobacteria atypical lipopolysaccharides

Lipopolysaccharides (LPS) are major players in bacterial infection through the recognition by Toll-like receptor 4 (TLR4). The LPS chemical structure, including the oligosaccharide core and the lipid A moiety, can be strongly influenced by adaptation and modulated to assure bacteria protection, evade immune surveillance, or reduce host immune responses. Deep structural understanding of TLRs signaling is essential for the modulation of the innate immune system in sepsis control and inflammation, during bacterial infection. To advance this knowledge, we have employed computational techniques to characterize the TLR4 molecular recognition of atypical LPSs from different opportunistic members of α2-Proteobacteria, including Brucella melitensis, Ochrobactrum anthropi, and Ochrobactrum intermedium, with diverse immunostimulatory activities. We contribute to unraveling the role of uncommon lipid A chemical features such as bearing very long-chain fatty acid chains, whose presence has been rarely reported, on modulating the proper heterodimerization of the TLR4 receptor complex. Moreover, we further evaluated the influence of the different oligosaccharide cores, including sugar composition and net charge, on TLR4 activation. Our studies contribute to elucidating, from the molecular and biological perspectives, the impact of the α2-Proteobacteria LPS cores and the chemical structure of the atypical lipid A for immune system evasion in opportunistic bacteria.