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Frontiers in Microbiology 2022The current symbiotic view of the organisms also calls for new approaches in the way we perceive and manage our pest species. The olive fruit fly, the most important...
The current symbiotic view of the organisms also calls for new approaches in the way we perceive and manage our pest species. The olive fruit fly, the most important olive tree pest, is dependent on an obligate bacterial symbiont to its larvae development in the immature fruit. This symbiont, (.) Erwinia dacicola, is prevalent throughout the host life stages, and we have shown significant changes in its numbers due to olive fruit fly metamorphosis. The olive fruit fly microbiota was analyzed through 16S metabarcoding, at three development stages: last instar larvae, pupae, and adult. Besides . E. dacicola, the olive fruit flies harbor a diverse bacterial flora of which 13 operational taxonomic units (grouped in 9 genera/species) were now determined to persist excluding at metamorphosis ( sp., sp., sp., sp., sp., sp., sp., sp., and sp.). These findings open a new window of opportunities in symbiosis-based pest management.
PubMed: 35509306
DOI: 10.3389/fmicb.2022.868458 -
Annals of Clinical Microbiology and... Nov 2023Globally, surgical site infections (SSI) are the most commonly reported healthcare-associated infections.
BACKGROUND
Globally, surgical site infections (SSI) are the most commonly reported healthcare-associated infections.
METHODS
A multicentre study was conducted among patients who underwent surgical procedures at four hospitals located in Northern (Debre Tabor), Southern (Hawassa), Southwest (Jimma), and Central (Tikur Anbessa) parts of Ethiopia. A total of 752 patients clinically studied for surgical site infection were enrolled. The number of patients from Debre Tabor, Hawassa, Jimma, and Tikur Anbessa, hospitals was 172, 184, 193, and 203, respectively. At each study site, SSI discharge culture was performed from all patients, and positive cultures were characterized by colony characteristics, Gram stain, and conventional biochemical tests. Each bacterial species was confirmed using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI TOF). An antimicrobial susceptibility test (AST) was done on Mueller-Hinton agar using the disk diffusion method. Logistic regression analysis was used to assess associations of dependent and independent variables. A p-value < 0.05 was considered statistically significant. Data were analysed using STATA 16 software.
RESULTS
Among 752 wound discharge cultures performed, 65.5% yielded growth. Among these, 57.9% and 42.1% were Gram-negative and Gram-positive isolates, respectively. In this study, a total of 494 bacteria were isolated; Staphylococcus aureus (31%), Escherichia coli (20.7%), and Klebsiella pneumoniae (9.8%) were the most common. Rare isolates (0.8% each) included Raoultella ornithinolytica, Stenotrophomonas maltophilia, Alcalignes faecalis, Pantoea ecurina, Bacillus flexus, and Paenibacillus tylopili. Enterobacteriaceae showed high levels of resistance to most of the tested antibiotics but lower levels of ertapenem (32.9%), amikacin (24.3%), imipenem (20.3%), and meropenem (17.6%) resistance. Multidrug-resistant (MDR) frequency of Enterobacteriaceae at Debre Tabor, Hawassa, Jimma, and Tikur Anbessa hospitals was 84.5%, 96.5%, 97.3%, and 94%, respectively. Ages ≥ 61 years (AOR = 2.83, 95% CI: 1.02-7.99; P 0.046), prolonged duration of hospital stay (AOR = 4.15, 95% CI: 2.87-6.01; P 0.000), history of previous antibiotics use (AOR = 2.83, 95% CI: 1.06-2.80; P 0.028), history of smoking (AOR = 2.35, 95% CI: 1.44-3.83; P 0.001), emergency surgery (AOR = 2.65, 95% CI: 1.92-3.66; P 0.000), and duration of operation (AOR = 0.27, 95% CI: 0.181-0.392; P 0.000) were significant risk factors.
CONCLUSION
The most prevalent isolates from Gram-positive and Gram-negative bacteria across all hospitals were S. aureus and E. coli, respectively. Many newly emerging Gram-negative and Gram-positive bacteria were identified. Variation between hospitals was found for both SSI etiology type and MDR frequencies. Hence, to prevent the emergence and spread of MDR bacteria, standard bacteriological tests and their AST are indispensable for effective antimicrobial stewardship.
Topics: Humans; Anti-Bacterial Agents; Surgical Wound Infection; Cross-Sectional Studies; Staphylococcus aureus; Escherichia coli; Ethiopia; Prospective Studies; Gram-Negative Bacteria; Gram-Positive Bacteria; Drug Resistance, Bacterial; Microbial Sensitivity Tests; Bacteria; Drug Resistance, Multiple, Bacterial
PubMed: 37936207
DOI: 10.1186/s12941-023-00643-6 -
Frontiers in Microbiology 2021Endophytic nitrogen-fixing (diazotrophic) bacteria are essential members of the microbiome of switchgrass (), considered to be an important commodity crop in bioenergy...
Endophytic nitrogen-fixing (diazotrophic) bacteria are essential members of the microbiome of switchgrass (), considered to be an important commodity crop in bioenergy production. While endophytic diazotrophs are known to provide fixed atmospheric nitrogen to their host plant, there are many other plant growth-promoting (PGP) capabilities of these organisms to be demonstrated. The diversity of PGP traits across different taxa of switchgrass-colonizing endophytes is understudied, yet critical for understanding endophytic function and improving cultivation methods of important commodity crops. Here, we present the isolation and characterization of three diazotrophic endophytes: R1C, F10Cl, and R1Gly. Strains R1C and F10Cl were isolated from switchgrass and strain R1Gly, while isolated from tobacco, is demonstrated herein to colonize switchgrass. Each strain exhibited highly diverse genomic and phenotypic PGP capabilities. Strain F10Cl and R1Gly demonstrated the highest functional similarity, suggesting that, while endophyte community structure may vary widely based on host species, differences in functional diversity are not a clearly delineated. The results of this study advance our understanding of diazotrophic endophyte diversity, which will allow us to design robust strategies to improve cultivation methods of many economically important commodity crops.
PubMed: 34867848
DOI: 10.3389/fmicb.2021.730440 -
Food Research International (Ottawa,... Dec 2022Edible flowers have been widely consumed fresh in drinks, salads, desserts and salty dishes. This study evaluated the color parameters, chemical composition (phenolics,...
Edible flowers have been widely consumed fresh in drinks, salads, desserts and salty dishes. This study evaluated the color parameters, chemical composition (phenolics, sugars, organic acids), volatiles compounds and microbiota (bacterial and fungal communities) in edible purple flowers (Torenia fournieri F. Lind.) cultivated in biocompost and traditional organic systems. Torenia flowers cultivated in biocompost had high (p < 0.05) contents of anthocyanins (cyanidin 3,5-diglucoside, delphinidin 3-glucoside), flavonols (quercitin 3-glycoside, myricetin and rutin), sugars (rhamnose and glucose), organic acids (citric and succinic), aldehydes (hexanal, cis-2-hexenal and trans-2-hexenal), and alcohols (trans-2-hexenol and 3-ethyl-4-methylpentan-1-ol). Flowers cultivated in biocompost showed higher (p < 0.05) abundance Cyanobacteria and Basidiomycota bacterial and fungal phyla, respectively, than flowers cultivated in traditional system. The high abundance of Oxyphotobacteria and Dothideomycetes classes, Acetobacterales and Cladosporiales orders, Oxyphotobacteriaceae and Cladosporiaceae families, and Raoultella and Cladosporium genera characterized torenia flowers cultivated in biocompost. The cultivation system influenced the torenia flowers microbiota and composition, primarily due to environmental response and enhanced uptake of nutrients. Our findings indicate that cultivation of torenia using the agroindustrial based-biocompost improves bioactive and volatiles contents in more purple and fruity flavored flowers, rendering flowers more attractive for consumption.
Topics: Humans; Anthocyanins; Microbiota; Flowers; Mycobiome; Sugars
PubMed: 36461288
DOI: 10.1016/j.foodres.2022.111973 -
Infection and Drug Resistance 2021is an aerobic gram-negative rod predominantly found in soil and aquatic environments. The typical reservoirs of spp. include the gastrointestinal tract and the upper...
INTRODUCTION
is an aerobic gram-negative rod predominantly found in soil and aquatic environments. The typical reservoirs of spp. include the gastrointestinal tract and the upper respiratory tract. It usually causes pneumonia, biliary tract infections, and bacteremia. Urinary tract infection (UTI) secondary to is an uncommon entity. Less than 10 cases of -associated UTIs in adults have been published in the literature to date.
OBJECTIVE
This is a single institution retrospective study undertaken to identify the epidemiology, patient characteristics, clinical spectrum, predisposing risk factors and the outcome of patients with UTI caused by
RESULTS
A total of 37 isolates were identified in urine samples over a 5-year study period. The mean age of the patient population was 77 years. The most common comorbidity was diabetes mellitus, which was present in 16 patients. Only 3 patients had a history of steroid use, an immunosuppressive condition, or were on chemotherapy. The most common presenting complaint was altered mental status followed by fever. Resistance to ampicillin was found in 35 isolates which seems to be an intrinsic characteristic of spp. and 2 isolates were multidrug-resistant, but still susceptible to ciprofloxacin. The average length of stay was 3 days, and the average duration of antibiotic administration was 8 days. Ciprofloxacin was the most frequently prescribed antibiotic (9 patients). The severity of infection ranged from simple cystitis in 15 patients to urosepsis in 2 patients and septic shock in 2 patients. There were no mortalities in our cohort.
CONCLUSION
Our study revealed that patients with UTI had higher proportion of diabetes mellitus, renal failure compared to the general population. Our study also confirms the intrinsic resistance to ampicillin of spp., which has been documented previously in the literature.
PubMed: 34103946
DOI: 10.2147/IDR.S306632 -
Frontiers in Microbiology 2023Rapid industrialization and urbanization have led to widespread metal contamination in aquatic ecosystems. This study explores the metal tolerance and biosorption...
Rapid industrialization and urbanization have led to widespread metal contamination in aquatic ecosystems. This study explores the metal tolerance and biosorption characteristics of four bacterial strains ( sp. L2, sp. L30, sp. R3, and sp. R19) isolated from Saint Clair River sediments. These strains effectively removed various metal cations (As, Pb, Cu, Mn, Zn, Cd, Cr, and Ni) in single and multi-metal solutions. Minimum inhibitory concentration (MIC) assays revealed strain-specific variations in metal tolerance, with L2 and L30 exhibiting higher tolerance. Surprisingly, R3 and R19, despite lower tolerance, demonstrated superior metal removal efficiency, challenging the notion that tolerance dictates removal efficacy. In single-metal solutions, R3 and R19 excelled at extracting various metal ions, while competitive binding in multi-metal solutions hindered removal. However, R3 and R19 retained higher removal efficiencies, possibly due to enhanced flocculation activities facilitating metal-ion contact. Comprehensive Fourier-transform infrared (FTIR) analysis highlighted the strains' metal-binding capabilities, with novel peaks emerging after metal exposure, indicative of extracellular polymeric substance (EPS) production. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) confirmed metal accumulation on bacterial surfaces and within cytoplasmic regions and revealed morphological changes and metal adsorption patterns, emphasizing the strains' ability to adapt to metal stress. Scanning transmission microscopy (STEM) and EDX analysis uncovered metal accumulation within bacterial cells, underscoring the complexity of microbial-metal interactions. This study also confirms that the simultaneous presence of an aqueous solution may cause a mutual inhibition in the adsorption of each metal to the EPS resulting in reduced metal uptake, which emphasizes the need to select specific bacterial strains for a given metal-containing effluent. The differences in metal distribution patterns between sp. R19 and sp. L30 suggest species-specific metal accumulation strategies driven by environmental conditions and metal availability. The heavy metal-removing capabilities and the ability to grow over a wide range of metal concentrations of the strains used in this study may offer an advantage to employ these organisms for metal remediation in bioreactors or .
PubMed: 37942073
DOI: 10.3389/fmicb.2023.1278886 -
Antibiotics (Basel, Switzerland) Jun 2022The emergence and spread of antimicrobial resistance (AMR) has become a persistent problem globally. In this study, an ozone treatment facility was established for an...
The emergence and spread of antimicrobial resistance (AMR) has become a persistent problem globally. In this study, an ozone treatment facility was established for an advanced hospital wastewater treatment in a core hospital facility in an urban area in Japan to evaluate the inactivation of antimicrobial-resistant bacteria and antimicrobials. Metagenomic DNA-seq analysis and the isolation of potential extended-spectrum -lactamase (ESBL)-producing bacteria suggested that ozone exposure for at least 20 min is required for the adequate inactivation of DNA and ESBL-producing bacteria. and species were markedly susceptible to 20-min ozone exposure, whereas and were isolated even after an 80-min exposure. These ozone-resistant bacteria might play a pivotal role as AMR reservoirs in the environment. Nine antimicrobials (ampicillin, cefdinir, cefpodoxime, ciprofloxacin, levofloxacin, clarithromycin, chlortetracycline, minocycline, and vancomycin) were detected at 373 ng/L to 27 μg/L in the hospital wastewater, and these were removed (96-100% removal) after a 40-min treatment. These results facilitate a comprehensive understanding of the AMR risk posed by hospital wastewater and provides insights for devising strategies to eliminate or mitigate the burden of antimicrobial-resistant bacteria and the flow of antimicrobials into the environment. To the best of our knowledge, this is the first report on the implementation of a batch-type, plant-scale ozone treatment system in a hospital facility to execute and evaluate the inactivation of drug-resistant bacteria and antimicrobials.
PubMed: 35884116
DOI: 10.3390/antibiotics11070862 -
Microbiological Research Jan 2023of the current research was to use plant growth promoting rhizobacteria for sequestration and biotransformation of the toxic form of Cr and As into non-toxic form....
of the current research was to use plant growth promoting rhizobacteria for sequestration and biotransformation of the toxic form of Cr and As into non-toxic form. Remediating these contaminants using microbes is a common technique and rhizo-microbiota not only relieves metal stress but also acts as biofertilizers. Role of plant growth-promoting rhizobacterial (PGPR) strains Acinetobacter beijerinckii (C5) and Raoultella planticola (C9) in counteracting chromium and arsenic stress in soybean seedlings was assessed. The isolated rhizobacteria were able to tolerate excessive quantities (up to 1200 ppm) of chromate and arsenate in liquid media. Beside their growth in heavy metal containing media, the strains were able to bio-transform chromate and arsenate to their least toxic form. They released significant quantities of stress related metabolites including phenols, flavonoids, proline, sugars and protein even in the presence of 1200 ppm of the heavy metals. They also released several plant hormones together with indole-3-acetic acid (IAA), salicylic acid (SA) and gibberellins. Another important feature of the isolates was their ability to solubilize phosphate and release siderophores and exposure to different levels of the selected heavy metals enhanced phosphate solubilization potential of both the isolates by up to 2-fold. Release of siderophore in A. beijerinckii C5 was enhanced by increasing heavy metals concentration in the media but in case of R. planticola C9 a decline was noted. When inoculated on soybean seedlings, the isolates modulated several metabolites of the hos plant enabling them to combat heavy metal toxicity at different levels. The PGPR strains boosted host's antioxidants production which minimized the oxidative damage by scavenging excessive ROS produced under stress. Control plants showed upregulation of stress response metabolites compared to PGPR application, whereas, IAA and SA were significantly higher in PGPR associated seedlings. In conclusion, PGPR alters the physiological and metabolic responses of soybean enabling it to cope better with chromate and arsenic toxicity and grow well under the stress.
Topics: Plant Growth Regulators; Glycine max; Arsenates; Chromates; Arsenic; Metals, Heavy; Seedlings; Siderophores; Phosphates
PubMed: 36270107
DOI: 10.1016/j.micres.2022.127237 -
Cureus Oct 2020Introduction Universally, blood stream infections are linked with increasing morbidity and mortality. Timely diagnosis for identification of bacterial etiology, their...
Introduction Universally, blood stream infections are linked with increasing morbidity and mortality. Timely diagnosis for identification of bacterial etiology, their susceptibility pattern and choice of empiric treatment plays a vital role in management. Objective To reveal the etiological profile and antibiotic sensitivity in blood culture specimens in a tertiary care setting. Methods This descriptive study was carried out in pathology laboratory of a tertiary care hospital from August 2016 to July 2019. All the 750 blood culture bottles were processed and isolates were recognized by morphological appearance on recommended media, gram stain, and different biochemical tests using Analytic Profile Index. Antibiotic sensitivity was implemented by modified disc diffusion method as per Clinical and Laboratory Standards Institute (CLSI) principles (2019). Results Out of 750 blood samples, 212 (28.26%) were culture positive. The percentage of gram-negative bacilli (n = 105) and gram-positive cocci (n = 104) was almost same (49.52%), while candida spp. was recovered from three (1.41%) isolates. The identified gram-negative bacteria were E. coli and Acinetobacter baumannii each (19.04%), Klebsiella pneumoniae and Pseudomonas aeruginosa each (16.19%), Enterobacter cloaca (11.42%), Salmonella typhi (8.57%), Burkholderia cepacia (1.90%), and Raoultella terrigena (7.61%). Among gram-positive isolates, coagulase-negative staphylococci (79.80%), Staphylococcus aureus (6.73%), Enterococcus spp. (11.53%) and Streptococcus spp. (1.92%) were recovered. Colistin, imipenem, meropenem, and amikacin were most successful against gram-negative rods. The sensitivity to vancomycin, teicoplanin and linezolid was 100%, for gram positive organisms. Methicillin resistance was present in 84.4% Staphylococcal isolates. Conclusion Local data showing changing etiological pattern and antibiogram of isolated pathogens, along with adequate infection prevention and control measures can be useful to improve patient care, in terms of hospital stay, duration of medication and treatment cost.
PubMed: 33209556
DOI: 10.7759/cureus.11000 -
Research in Microbiology 2022
Corrigendum to "Proposal for reunification of the genus Raoultella with the genus Klebsiella and reclassification of Raoultella electrica as Klebsiella electrica comb. nov." [Res microbiol 172 (2021) 103851].
PubMed: 35816932
DOI: 10.1016/j.resmic.2022.103924