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Malawi Medical Journal : the Journal of... Dec 2023Various infective complications can be seen after a dental procedure. They are rarely resistant to standard therapy. In the case we present, a case of preseptal...
Various infective complications can be seen after a dental procedure. They are rarely resistant to standard therapy. In the case we present, a case of preseptal cellulitis caused by pseudomonas oryzihabitans after tooth extraction in a male patient who did not have any underlying cause. As in our case, evaluation of the cases resistant to standard treatment in terms of drainage and multidisciplinary management of culture results together with infectious diseases will increase the treatment success rate.
Topics: Humans; Male; Cellulitis; Pseudomonas; Eyelid Diseases; Anti-Bacterial Agents
PubMed: 38362568
DOI: 10.4314/mmj.v35i4.7 -
Plant Disease Nov 2023China ranks first in the production and harvest area of walnut ( L.) worldwide. Currently, the poor health and low yield of walnut caused by pathogen infection is of...
China ranks first in the production and harvest area of walnut ( L.) worldwide. Currently, the poor health and low yield of walnut caused by pathogen infection is of concern. In 2022, severe walnut leaf spot disease was observed on the seedlings of four walnut nurseries (0.08 to 0.23 ha) in Liaocheng, Shandong, China, with an average incidence of 48.6% (from 34.6% to 65.3% on the cultivar Xiangling). From August to October, leaf spots mainly appeared on the edges of the leaflets, and occasionally between veins. The lesions were initially soft and rotten, and then light brown, round to semi-circular. Subsequently, the adjacent lesions fused, and the edges of the leaflets and entire leaflets showed symptoms of browning and wilting. For pathogen isolation, five leaflets with representative symptoms from one of the nurseries were collected and wiped three times with sterile absorbent cotton dipped in 75% alcohol and washed with distilled water. Leaflet pieces at the junction of the lesion and healthy tissues were removed, crushed in a sterile mortar, and soaked in a small amount of distilled water for 10 min. The diseased tissue suspension was streaked on a nutrient agar medium (NA) with a sterile inoculation ring and incubated at 28°C for 24 to 72 h. The bacterial colonies obtained were further cultured on NA. The purified colonies were uniform in shape, round, and yellow, with a raised, shiny surface and smooth margin. The isolates were Gram-negative, and the electron microscope analysis showed that the pathogens were short rods (0.35 to 0.52 × 0.90 to 1.24 μm, average = 0.44 ± 0.05 × 1.08 ± 0.11 μm, n = 25). For bacterial species identification, a single-colony culture was subjected to genomic DNA extraction and gene amplification and sequencing of 16S rRNA, D, and B. The universal primers 27F/1492R (Lane 1991) were used to amplify the 16S rRNA gene and the specific primers 70F/70R and UP-1E/APrU (Yamamoto et al. 2000) were used to amplify the D and genes, respectively. In the BLAST analysis, the 16S rRNA sequence (GenBank OR195734) of the isolate shared 99% similarity (1409/1410 bp) with strain IAM 1568T (AM262973.1), and the D (OR709708) and B (OR709707) sequences showed >98% identity to D (707/717 bp; FN554494.1) and B (787/801 bp; FN554210.1) of strain LMG 7040T. Based on the above results, the isolated bacterium was identified as . For the pathogenicity test, healthy leaflets from 10 two-year-old potted walnut seedlings (cv. Xiangling) were used as inoculation materials. The leaflets were punctured with a sterile inoculation needle of 0.4 mm, and three small holes on each leaflet at an interval of about 5 mm were covered with a piece of sterile cotton. A bacterial suspension (1 ml) at 10 CFU/ml was spread onto the cotton, and wrapped with plastic film for 24 h. Water was used as a negative control. The inoculations were performed five times. Plants were grown outdoors at a daily average temperature of 22°C with relative humidity over 45%. Two days after inoculation, the disease began to develop in the leaflets with similar symptoms to those observed in the field. In contrast, control plants remained healthy and symptomless. Bacteria were reisolated from the inoculated walnut plants, and the morphology and 16S rRNA gene sequences of the isolates were the same as those of the original strains. Since it was discovered as an opportunistic human pathogenic bacterium in the 1970s (Keikha et al. 2019), has also been shown to cause certain plant diseases, such as panicle blight and grain discoloration on rice (Hou et al. 2020), fruit black rot on prickly ash (Liu et al. 2021), and stem and leaf rot on muskmelon (Li et al. 2021). As far as we know, this is the first report of causing walnut leaf spot disease in China. Leaf spot caused by may be a threat to walnut cultivation, and this report of its occurrence is the first step in determining potential spread and effective control measures.
PubMed: 37923975
DOI: 10.1094/PDIS-08-23-1634-PDN -
Microorganisms Apr 2023The aim of this work was to assess the natural microbiota of packed fresh-cut apples during refrigerated storage. Two different films were tested for the package, a...
The aim of this work was to assess the natural microbiota of packed fresh-cut apples during refrigerated storage. Two different films were tested for the package, a biodegradable (PLA) film and a conventional and commercial one (OPP). Two antioxidant additives were applied, a natural olive pomace extract and the commercial ascorbic acid used by the industries. The results revealed lower bacteria counts in samples with olive pomace extract and PLA films than in those with ascorbic acid and OPP films after 5 and 12 days of storage. These findings suggest that the use of such natural extracts as additives in fruits could delay the growth of mesophilic bacteria. The characterization and identification of the bacterial isolates from fresh-cut apple samples showed that the most prevalent species were , , , , , spp., and spp. Furthermore, an increase in the microbial diversity during the storage time at refrigerated temperatures was observed, except for the sample treated with olive pomace extract and packaged in OPP film. The highest microbial diversity was found for samples with ascorbic acid as an additive. This could indicate a negative effect of ascorbic acid on the microbial inhibition of apple slices. The natural olive pomace extract demonstrated potential as an antimicrobial additive for fresh-cut apples.
PubMed: 37317130
DOI: 10.3390/microorganisms11051157 -
Frontiers in Public Health 2023Cutaneous tuberculosis (CTB) and its paucibacillary forms are rare and difficult to diagnose, especially in immunocompromised patients with significant comorbidity. The...
BACKGROUND
Cutaneous tuberculosis (CTB) and its paucibacillary forms are rare and difficult to diagnose, especially in immunocompromised patients with significant comorbidity. The aim of the study was to introduce the modern concept of the microbiome and diagnostic chain into clinical practice (patient-centered care) with the presentation of an atypical form of cutaneous tuberculosis with necrotizing non-healing ulcers leading to polymicrobial infection.
METHODS
The study material included samples from sputum, broncho-alveolar lavage and skin ulcer, taken from a patient developing cutaneous tuberculosis. The microbiological investigation was performed, and identification of the isolates was carried out using genotyping and the matrix-assisted laser desorption ionization-time of flight mass spectrometry.
RESULTS
The immunocompromised patient with humoral abnormality (plasma cell dyscrasia) and severe paraproteinemia developed multiorgan tuberculosis. Although cutaneous manifestation preceded systemic and pulmonary symptoms (approximately half a year), the mycobacterial genotyping confirmed the same MTB strain existence in skin ulcers and the respiratory system. Therefore, the infectious chain: transmission, the portal of entry, and bacterial spreading , were unclear. Microbial diversity found in wound microbiota (among others , and ) was associated with the spread of a skin lesion. The biofilm-forming capacity of strains isolated from the wound may represent the potential virulence of these strains. Thus, the role of polymicrobial biofilm may be crucial in ulcer formation and CTB manifestation.
CONCLUSIONS
Severe wound healing as a unique biofilm-forming niche should be tested for Mycobacterium (on species and strain levels) and coexisting microorganisms using a wide range of microbiological techniques. In immunodeficient patients with non-typical CTB presentation, the chain of transmission and MTB spread is still an open issue for further research.
Topics: Humans; Tuberculosis; Biofilms
PubMed: 37213612
DOI: 10.3389/fpubh.2023.1091373 -
Journal of Experimental Botany Nov 2022Soil bacteria promote plant growth and protect against environmental stresses, but the mechanisms involved remain poorly characterized, particularly when there is no...
Soil bacteria promote plant growth and protect against environmental stresses, but the mechanisms involved remain poorly characterized, particularly when there is no direct contact between the roots and bacteria. Here, we explored the effects of Pseudomonas oryzihabitans PGP01 on the root system architecture (RSA) in Arabidopsis thaliana seedlings. Significant increases in lateral root (LR) density were observed when seedlings were grown in the presence of P. oryzihabitans, as well as an increased abundance of transcripts associated with altered nutrient transport and phytohormone responses. However, no bacterial transcripts were detected on the root samples by RNAseq analysis, demonstrating that the bacteria do not colonize the roots. Separating the agar containing bacteria from the seedlings prevented the bacteria-induced changes in RSA. Bacteria-induced changes in RSA were absent from mutants defective in ethylene response factor (ERF109), glutathione synthesis (pad2-1, cad2-1, and rax1-1) and in strigolactone synthesis (max3-9 and max4-1) or signalling (max2-3). However, the P. oryzihabitans-induced changes in RSA were similar in the low ascorbate mutants (vtc2-1and vtc2-2) to the wild-type controls. Taken together, these results demonstrate the importance of non-volatile signals and redox mechanisms in the root architecture regulation that occurs following long-distance perception of P. oryzihabitans.
Topics: Arabidopsis; Plant Roots; Pseudomonas; Seedlings; Oxidation-Reduction; Gene Expression Regulation, Plant; Transcription Factors; Arabidopsis Proteins
PubMed: 36001048
DOI: 10.1093/jxb/erac346 -
Plant Disease Jul 2022Tobacco (Nicotiana tabacum) is an economically important crop, and its productivity is challenged due to pathogen infection. In 2020 and 2021, a previously...
Tobacco (Nicotiana tabacum) is an economically important crop, and its productivity is challenged due to pathogen infection. In 2020 and 2021, a previously uncharacterized disease was observed on field grown tobacco (Variety NC102) in Zhucheng City, Shandong Province, China (119°7'14" E, 36°0'58" N), where tobacco has been grown for decades. The disease can be found throughout the growth period of tobacco and mainly occurred from fast growing period (about 13-16 leaves) to leaf maturity stage. In severely diseased areas, the incidence rate can reach 100%. The symptoms first began as chlorotic water stain like small spots, then the spots merged into larger irregular necrotic maculae around the chlorotic halos. Small pieces of symptomatic leaves from 10 different infected plants were collected for pathogen isolation. The small pieces of discolored leaves were surface sterilized with 75% ethanol for 40s and washed with sterile water for three times. The sterilized leaves were ground with a glass rod with 1mL sterile water, and 100 μL suspensions were spread on nutrient agar medium then incubated at 28oC for 48 hours. Yellow round colonies with undulating edges were showed up on nutrient agar medium 48 hours later. Three isolates were randomly picked up from each of the 10 plates for subsequent analysis. After purification and culture on nutrient agar plate, the 16S rRNA gene of the 30 isolates were amplified with primers 27F and 1492R and the amplicons were sequenced and analyzed by sequence alignment. The sequence alignment results showed that the 16S rRNA nucleotide identity of the 30 isolates were 100%. One typical isolate named ZC5 was selected for subsequent analysis, and the resulting 16S rRNA sequence was deposited at GenBank, NCBI under accession OK092624. The 16S rRNA sequence identity with those of P. psychrotolerans strain K3-2 (KY882083) and M3-1 (KY882120) were 100%, respectively. The phenotypic analysis by Biolog Gen Ⅲ indicated that the bacterial isolate (ZC5) showed highest similarity (98.3%) with strain Pseudomonas oryzihabitans. P. oryzihabitans and P. psychrotolerans have a high degree of homology in the phylogenetic relationship based on the phylogenetic analysis of three concatenated sequences of gyrB, rpoB and rpoD genes (Mulet et al. 2010). The gyrB (ON462356), rpoB (ON462355), rpoD (ON462357) gene of isolate ZC5were also amplified and sequenced by using primers gyrB-For/gyrB-Rev, rpoB-For/rpoB-Rev and rpoD-For/rpoD-Rev (Hauser et al. 2004), respectively. While P. psychrotolerans and P. oryzihabitans form the same clade in phylogenies, strains of P. psychrotolerans do form a unique sub-clade. Isolate ZC5 clustered more closely with the type strain of P. psychrotolerans LMG 21977 in the phylogenetic tree. Therefore, based on the concatenated sequences of three genes (gyrB, rpoB and rpoD), the isolate ZC5 was confirmed as P. psychrotolerans. Based on morphological, Biolog characteristics and phylogenetic analysis, the isolate was identified as P. psychrotolerans. The tobacco plants at fast growing stage were selected for pathogenicity tests. Pathogenicity tests were conducted by injecting 10 μL bacterial suspension (108cfu/mL) of ZC5 into tobacco leaves with a syringe. Sterile water was inoculated into the tobacco leaves in the same way as the control. Six plants were selected for pathogenicity tests each time and five leaves of each tobacco plant were inoculated, and the tests were repeated three times. To simulate disease conditions in the natural environment, the inoculated plants were moved outdoors. The average temperature was 32°C during the day and 20°C at night. To maintain humidity, the tobacco leaves were sprayed with water every two days. Symptoms appeared on the pathogen inoculated leaves seven days after inoculation, whereas the control treatment remained symptomless. The pathogens were reisolated from diseased leaves and identified as P. psychrotolerans based on morphological, molecular and phylogenetic analysis, which fulfilled Koch's postulates. To our knowledge, this is the first report of tobacco bacterial leaf spot caused by P. psychrotolerans.
PubMed: 35852908
DOI: 10.1094/PDIS-05-22-1069-PDN -
Antibiotics (Basel, Switzerland) Jun 2022This study is focused on resistance to carbapenems and third-generation cephalosporins in Gram-negative microorganisms isolated from swine, whose transmission to humans...
This study is focused on resistance to carbapenems and third-generation cephalosporins in Gram-negative microorganisms isolated from swine, whose transmission to humans via pork consumption cannot be excluded. In addition, the common carriage of carbapenem-resistant (CR) bacteria between humans and pigs was evaluated. Sampling involved 300 faecal samples collected from slaughtered pigs and 300 urine samples collected from 187 hospitalised patients in Parma Province (Italy). In swine, MIC testing confirmed resistance to meropenem for isolates of and and resistance to cefotaxime and ceftazidime for , , , and . For , , , , and , no EUCAST MIC breakpoints were available. However, ESBL genes (, , , and ) and AmpC genes (, , and ) were found in 38 and 16 isolates, respectively. was the only CR species shared by pigs (4/300 pigs; 1.3%) and patients (2/187; 1.1%). ST938 carrying and was detected in one pig as well as an 83-year-old patient. Although no direct epidemiological link was demonstrable, SNP calling and cgMLST showed a genetic relationship of the isolates (86 SNPs and 661 allele difference), thus suggesting possible circulation of CR bacteria between swine and humans.
PubMed: 35740183
DOI: 10.3390/antibiotics11060777 -
BMC Plant Biology Jun 2022Chemical fertilisers are extensively used for crop production, which may cause soil deterioration and water pollution. Endophytic bacteria with plant-growth-promoting...
BACKGROUND
Chemical fertilisers are extensively used for crop production, which may cause soil deterioration and water pollution. Endophytic bacteria with plant-growth-promoting (PGP) activities may provide a solution to sustainably improve crop yields, including in-demand staples such as wheat. However, the diversity of the PGP endophytic bacteria in wheat across plant organs and growth stages has not been thoroughly characterised.
RESULTS
Here, we report the isolation of endophytic bacteria from root, stem, leaf and seed of three winter wheat varieties at tillering, jointing, heading and seed-filling growth stages that were identified via 16S rRNA gene sequence analysis. Strains were screened for indole-3-acetic acid (IAA) production, potassium and phosphate solubilisation and the ability to grow on a nitrogen-free medium. Strain's capacity to stimulate various plant growth parameters, such as dry root weight, dry above-ground parts weight and plant height, was evaluated in pot trials. A total of 127 strains were randomly selected from 610 isolated endophytic bacterial cultures, representing ten genera and 22 taxa. Some taxa were organ-specific; others were growth-stage-specific. Bacillus aryabhattai, B. stratosphericus, Leclercia adecarboxylata and Pseudomonas oryzihabitans were detected as wheat endophytes for the first time. The IAA production, inorganic phosphorous solubilisation, organic phosphorus solubilisation, potassium solubilisation and growth on N-free medium were detected in 45%, 29%, 37%, 2.4% and 37.8% of the 127 strains, respectively. In pot trials, each strain showed variable effects on inoculated wheat plants regarding the evaluated growth parameters.
CONCLUSIONS
Wheat endophytic bacteria showed organ- and growth-stage diversity, which may reflect their adaptations to different plant tissues and seasonal variations, and differed in their PGP abilities. Bacillus was the most predominant bacterial taxa isolated from winter wheat plants. Our study confirmed wheat root as the best reservoir for screening endophytic bacteria with potential as biofertilisers.
Topics: Bacteria; Endophytes; Phylogeny; Plant Roots; Potassium; RNA, Ribosomal, 16S; Triticum
PubMed: 35659526
DOI: 10.1186/s12870-022-03615-8 -
International Journal of Women's... Jun 2022
PubMed: 35619673
DOI: 10.1097/JW9.0000000000000024 -
AMB Express May 2022Psychrotrophic Pseudomonas is one of the significant microbes that lead to putrefaction in chilled meat. One of the biggest problems in the detection of Pseudomonas is...
Psychrotrophic Pseudomonas is one of the significant microbes that lead to putrefaction in chilled meat. One of the biggest problems in the detection of Pseudomonas is that several species are seemingly identical. Currently, antibiotic resistance is one of the most significant challenges facing the world's health and food security. Therefore, this study was designed to apply an accurate technique for eliminating the identification discrepancy of Pseudomonas species and to study their resistance against various antimicrobials. A total of 320 chicken meat specimens were cultivated, and the isolated bacteria' were phenotypically recognized. Protein analysis was carried out for cultured isolates via Microflex LT. The resistance of Pseudomonas isolates was recorded through Vitek® 2 AST-GN83 cards. Overall, 69 samples were identified as Pseudomonas spp. and included 18 Pseudomonas lundensis (P. lundensis), 16 Pseudomonas fragi (P. fragi), 13 Pseudomonas oryzihabitans (P. oryzihabitans), 10 Pseudomonas stutzeri (P. stutzeri), 5 Pseudomonas fluorescens (P. fluorescens), 4 Pseudomonas putida (P. putida), and 3 Pseudomonas aeruginosa (P. aeruginosa) isolates. Microflex LT identified all Pseudomonas isolates (100%) correctly with a score value ≥ 2.00. PCA positively discriminated the identified isolates into various groups. The antimicrobial resistance levels against Pseudomonas isolates were 81.16% for nitrofurantoin, 71% for ampicillin and ampicillin/sulbactam, 65.22% for cefuroxime and ceftriaxone, 55% for aztreonam, and 49.28% for ciprofloxacin. The susceptibilities were 100% for cefotaxime, 98.55% for ceftazidime, 94.20% for each piperacillin/tazobactam and cefepime, 91.3% for cefazolin. In conclusion, chicken meat was found to be contaminated with different Pseudomonas spp., with high incidence rates of P. lundensis. Microflex LT is a potent tool for distinguishing Pseudomonads at the species level.
PubMed: 35532863
DOI: 10.1186/s13568-022-01390-1