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Oman Journal of Ophthalmology 2023Endophthalmitis is an uncommon purulent inflammation of the intraocular fluids secondary to endogenous or exogenous causes. It is known that posttraumatic...
Endophthalmitis is an uncommon purulent inflammation of the intraocular fluids secondary to endogenous or exogenous causes. It is known that posttraumatic endophthalmitis had a notably poor visual outcome, and it poses therapeutic challenges. Therefore, early organism detection would be beneficial in therapeutic management and are able to reduce long-term complications. This case report describes a patient with a rare positive culture-proven endophthalmitis due to penetrating ocular trauma by a metal brush over the right eye. A 36-year-old man presented with progressively worsening right eye redness and blurring of vision with pain for 3 days following ocular penetration by a metal brush during grinding. On initial presentation, his visual acuity was 6/12 over the right eye and 6/6 over the left eye. His visual acuity deteriorated to hand movement 5 days later with worsening of ocular infection over the right eye despite topical and oral antibiotics. B-scan revealed dense vitreous infiltration. A vitreous tap was done, and a combination of intravitreal vancomycin and ceftazidime was administered. Vitreous culture isolated Gram negative The patient was planned for early vitrectomy; however, the patient opted for conservative treatment. Therefore, the patient received intravitreal vancomycin and intravitreal ceftazidime injections every 48-72 h. Published articles on endophthalmitis postocular penetration are extremely limited. This case report may provide a better understanding of the presentation and is able to aid with early diagnosis and treatment initiation for future reference.
PubMed: 38059095
DOI: 10.4103/ojo.ojo_298_22 -
Microbiology Resource Announcements Jan 2024Sphingomonadaceae are common membrane colonizers and biofilm formers. As part of our studies on long-term genetic changes in drinking water biofilm species, we report...
Sphingomonadaceae are common membrane colonizers and biofilm formers. As part of our studies on long-term genetic changes in drinking water biofilm species, we report the draft genome sequence of strain Sph5, isolated from a tap water filtration membrane. The isolate was determined as through whole genome sequencing and assembly.
PubMed: 38038463
DOI: 10.1128/MRA.00345-23 -
Frontiers in Cellular and Infection... 2023is a Gram-negative coccobacillus, which is a very rare human opportunistic pathogen causing pneumonia and systemic infection. It is difficult to identify this bacterium...
is a Gram-negative coccobacillus, which is a very rare human opportunistic pathogen causing pneumonia and systemic infection. It is difficult to identify this bacterium through conventional Gram-staining and biochemical methods due to an amorphous Gram stain appearance after 24 h culture and its relatively fastidious and slow growth giving weak and/or delayed reactions in biochemical tests. It is often misidentified as other bacteria including spp., , or False identification may delay the therapy of the patients and even endanger the patient's life. Here, we report a case of a 34-year-old man with acute lymphoblastic leukemia infected by , which was almost misdiagnosed. This case describes our identification of a patient with a systemic infection. To our knowledge, this is the first such case reported in China.
Topics: Male; Humans; Adult; Francisella; Bacteremia; Sepsis; Precursor Cell Lymphoblastic Leukemia-Lymphoma
PubMed: 37780860
DOI: 10.3389/fcimb.2023.1206972 -
Archives of Biochemistry and Biophysics Oct 20233,4-Dihydroxyphenylacetate (DHPA) 2,3-dioxygenase (EC 1.13.11.15) from Acinetobacter baumannii (AbDHPAO) is an enzyme that catalyzes the 2,3-extradiol ring-cleavage of...
3,4-Dihydroxyphenylacetate (DHPA) 2,3-dioxygenase (EC 1.13.11.15) from Acinetobacter baumannii (AbDHPAO) is an enzyme that catalyzes the 2,3-extradiol ring-cleavage of DHPA in the p-hydroxyphenylacetate (HPA) degradation pathway. While the biochemical reactions of various DHPAOs have been reported, only structures of DHPAO from Brevibacterium fuscum and their homologs are available. Here, we report the X-ray structure and biochemical characterization of an Fe-specific AbDHPAO that shares 12% sequence identity to the enzyme from B. fuscum. The 1.8 Å X-ray structure of apo-AbDHPAO was determined with four subunits per asymmetric unit, consistent with a homotetrameric structure. Interestingly, the αβ-sandwiched fold of the AbDHPAO subunit is different from the dual β-barrel-like motif of the well-characterized B. fuscum DHPAO structures; instead, it is similar to the structures of non-DHPA extradiol dioxygenases from Comamonas sp. and Sphingomonas paucimobilis. Similarly, these extradiol dioxygenases share the same chemistry owing to a conserved 2-His-1-carboxylate catalytic motif. Structure analysis and molecular docking suggested that the Fe cofactor and substrate binding sites consist of the conserved residues His12, His57, and Glu238 forming a 2-His-1-carboxylate motif ligating to Fe and DHPA bound with Fe in an octahedral coordination. In addition to DHPA, AbDHPAO can also use other 3,4-dihydroxyphenylacetate derivatives with different aliphatic carboxylic acid substituents as substrates, albeit with low reactivity. Altogether, this report provides a better understanding of the structure and biochemical properties of AbDHPAO and its homologs, which is advancing further modification of DHPAO in future applications.
PubMed: 37769893
DOI: 10.1016/j.abb.2023.109768 -
Microorganisms Sep 2023The pressing need to safeguard the health of astronauts aboard the International Space Station (ISS) necessitates constant and rigorous microbial monitoring. Recognizing...
The pressing need to safeguard the health of astronauts aboard the International Space Station (ISS) necessitates constant and rigorous microbial monitoring. Recognizing the shortcomings of traditional culture-based methods, NASA is deliberating the incorporation of molecular-based techniques. The challenge, however, lies in developing and validating effective methods for concentrating samples to facilitate this transition. This study is dedicated to investigating the potential of an ISS Smart Sample Concentrator (iSSC) as an innovative concentration method. First, the iSSC system and its components were tested and optimized for microgravity, including various testing environments: a drop tower, parabolic flight, and the ISS itself. Upon confirming the system's compatibility with microgravity, we further evaluated its proficiency and reliability in concentrating large volumes (i.e., 1 L) of water samples inoculated with different microbes. The samples carried 10 to 10 colony-forming units (CFUs) of , , or per liter, aligning with NASA's acceptable limit of 5 × 10 CFU/L. The average retrieved volume post-concentration was ≈450 µL, yielding samples that were ≈2200 times more concentrated for subsequent quantitative PCR (qPCR) and CFU analysis. The average microbial percent recovery, as assessed with CFU counts, demonstrated consistency for and at around 50% and 45%, respectively. For , the efficiency oscillated between 40% and 80%. Interestingly, when we examined microbial recovery using qPCR, the results showed more variability across all tested species. The significance of these findings lies not merely in the successful validation of the iSSC but also in the system's proven consistency, as evidenced by its alignment with previous validation-phase results. In conclusion, conducted research underscored the potential of the iSSC in monitoring microbial contamination in potable water aboard the ISS, heralding a paradigm shift from culture-based to molecular-based monitoring methods.
PubMed: 37764154
DOI: 10.3390/microorganisms11092310 -
Cureus Jul 2023Introduction Non-fermenting Gram-negative bacilli (NFGNB) are emerging superbugs of bloodstream infections (BSI), causing increased mortality in hospitalized patients....
Introduction Non-fermenting Gram-negative bacilli (NFGNB) are emerging superbugs of bloodstream infections (BSI), causing increased mortality in hospitalized patients. NFGNB are challenging to identify using conventional identification techniques. Hence, automation is beneficial for accurate and fast diagnosis; it also facilitates rapid treatment and recovery of patients. This study aims to isolate/identify NFGNB from BSI and determine its antimicrobial susceptibility pattern. Material and methods This study was conducted in the Department of Microbiology, LLRMMC, Meerut, for a period of six months (June to November 2022). The samples were processed using automated blood culture (BD BACTEC) and an identification/sensitivity testing system (BD Phoenix). Results Out of 1340 blood cultures, 347 (25.7%) were flagged positive for microbial growth. A total of 103 (7.6%) NFGNB were isolated, showing their strong association with BSI. The NFGNB isolates were 23 (22.3%), 19 (18.4%), spp. 19 (18.4%), 17 (16.5%), 5 (4.8%), sp. 4 (3.8%), 3 (2.9%), 3 (2.9%), 2 (1.9%), 2 (1.9%), 2 (1.9%), 2 (1.9%), 1 (0.9%), and 1 (0.9%). Conclusions Automation helps in the prompt reporting of NFGNB and their antibiogram pattern by microbiology laboratories, facilitating the early and accurate management of patients with BSI.
PubMed: 37551224
DOI: 10.7759/cureus.41484 -
Clinical Case Reports Jul 2023can cause infection in healthy people. As this bacterium is slow-growing, special attention should be paid to the timely diagnosis and control of its antibiotic...
KEY CLINICAL MESSAGE
can cause infection in healthy people. As this bacterium is slow-growing, special attention should be paid to the timely diagnosis and control of its antibiotic resistance to prevent the spread of resistant strains.
ABSTRACT
This study reports a case of ocular infection caused by and its treatment with various antibiotics. A middle-aged woman with prolonged purulent eye discharge was admitted to an ophthalmology clinic in Qazvin, Iran. A strain of was isolated from the patient. The sample was identified by Sanger sequencing of the 16s rRNA gene, and an antibiogram test was performed to determine its resistance profile. The patient was treated with ceftazidime and levofloxacin eye drops. The bacterial culture was negative 18 days after starting ceftazidime and levofloxacin treatment. The antibiogram results showed that the isolated bacterium was resistant to aminoglycosides and colistin. This study highlights that can cause disease even in immunocompetent individuals. Due to the different resistance profiles of this bacterium, treatment should be based on antibiogram results.
PubMed: 37476596
DOI: 10.1002/ccr3.7715 -
MicrobiologyOpen Jun 2023Lindane (γ-HCH) is an organochlorine pesticide that causes huge environmental concerns worldwide due to its recalcitrance and toxicity. The use of the cyanobacterium...
Lindane (γ-HCH) is an organochlorine pesticide that causes huge environmental concerns worldwide due to its recalcitrance and toxicity. The use of the cyanobacterium Anabaena sp. PCC 7120 in aquatic lindane bioremediation has been suggested but information relative to this process is scarce. In the present work, data relative to the growth, pigment composition, photosynthetic/respiration rate, and oxidative stress response of Anabaena sp. PCC 7120 in the presence of lindane at its solubility limit in water are shown. In addition, lindane degradation experiments revealed almost a total disappearance of lindane in the supernatants of Anabaena sp. PCC 7120 culture after 6 days of incubation. The diminishing in lindane concentration was in concordance with an increase in the levels of trichlorobenzene inside the cells. Furthermore, to identify potential orthologs of the linA, linB, linC, linD, linE, and linR genes from Sphingomonas paucimobilis B90A in Anabaena sp. PCC 7120, a whole genome screening was performed allowing the identification of five putative lin orthologs (all1353 and all0193 putative orthologs of linB, all3836 putative orthologs of linC, and all0352 and alr0353 putative orthologs of linE and linR, respectively) which could be involved in the lindane degradation pathway. Differential expression analysis of these genes in the presence of lindane revealed strong upregulation of one of the potential lin genes of Anabaena sp. PCC 7120.
Topics: Hexachlorocyclohexane; Pesticides; Hydrocarbons, Chlorinated; Genes, Bacterial; Anabaena; Biodegradation, Environmental
PubMed: 37379427
DOI: 10.1002/mbo3.1355 -
International Journal of Biological... Jul 2023Gellan gum (GG) is used in many industries. Here, we obtained a low molecular weight GG (L-GG) directly produced by M155, the high-yield mutant strain of Sphingomonas...
Gellan gum (GG) is used in many industries. Here, we obtained a low molecular weight GG (L-GG) directly produced by M155, the high-yield mutant strain of Sphingomonas paucimobilis ATCC 31461, which was selected using UV-ARTP combined mutagenesis. The molecular weight of L-GG was 44.6 % lesser than that of the initial GG (I-GG), and the GG yield increased by 24 %. The monosaccharide composition and Fourier transform-infrared spectroscopic patterns of L-GG were similar to those of I-GG, which indicated that the decrease in the molecular weight of L-GG was probably because of reduction in the degree of polymerization. In addition, microstructural analysis revealed that the surface of L-GG was rougher, with smaller pores and tighter network, than that of I-GG. L-GG showed low hardness, gumminess, and chewiness, which are indicative of better taste. The results of rheological analysis revealed that the L-GG solution is a typical non-Newtonian fluid with low viscoelasticity, which exhibited stable dynamic viscoelasticity within 20-65 °C. To the best of our knowledge, this is the first report of direct biosynthesis of low molecular weight GG during fermentation, which will reduce the manufacturing costs. Our observations provide a reference for precise and expanded applications of GG.
Topics: Molecular Weight; Fermentation; Polysaccharides, Bacterial; Sphingomonas
PubMed: 37196715
DOI: 10.1016/j.ijbiomac.2023.124899 -
Brazilian Journal of Microbiology :... Sep 2023Silver (Ag) is currently obtained from primary and secondary sources through hydrometallurgical and pyrometallurgical processes. However, these processes consume high...
Silver (Ag) is currently obtained from primary and secondary sources through hydrometallurgical and pyrometallurgical processes. However, these processes consume high amounts of energy and are environmentally unfriendly. The search for bacteria tolerant with a high leaching capacity for to Ag is therefore a necessary requirement as part of the development of bioleaching technologies with reduced impact on the environment and lower energy expenditure. In this sense, the objective of this research was to evaluate the tolerance of Sphingomonas paucimobilis MX8 to Ag added to nutrient agar, and to determine whether this tolerance could favor the bioleaching of Ag present on the printed circuit boards (PCBs) of computer keyboards. The bacteria Sphingomonas paucimobilis MX8 was cultured in Petri dishes with nutrient agar and four different concentrations of AgNO (200, 400, 600, and 800 mg L) at 28 °C for 10 days. For the bioleaching experiment, the bacteria were grown in a mineral medium with computer keyboard PCBs for 30 days at room temperature (17 to 22 °C) and centrifugation at 150 rpm. The results indicate that Sphingomonas paucimobilis MX8 is tolerant to Ag and forms a silvery halo around its growth in the presence of this metal. Furthermore, Sphingomonas paucimobilis MX8 was able to bioleach 12% of the Ag found in computer keyboard PCBs. The results obtained could help generate more environmentally friendly silver bioleaching processes in which the silver bioleaching capacity of this bacterium is increased.
Topics: Silver; Agar; Recycling; Electronic Waste; Culture Media; Bacteria; Computers
PubMed: 37171535
DOI: 10.1007/s42770-023-00994-4