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Food Technology and Biotechnology Mar 2022Shrimp shells contain chitin that can be further processed into acetylglucosamine, which has been extensively used to treat joint damage. has a strong chitinolytic...
RESEARCH BACKGROUND
Shrimp shells contain chitin that can be further processed into acetylglucosamine, which has been extensively used to treat joint damage. has a strong chitinolytic activity and may be utilized in the form of immobilized cells in repeated fermentation. Pumice is a porous and rigid stone that offers superior mechanical strength, making it suitable for immobilization.
EXPERIMENTAL APPROACH
In the research submerged fermentation with different pumice stone sizes and pumice stone/growth medium ratios (/) was carried out for 4 days at 37 °C and pH=7.0. The optimum pumice stone size and pumice stone/growth medium ratio (/) were used to determine the optimum fermentation cycle for the production of acetylglucosamine using immobilized .
RESULTS AND CONCLUSIONS
Pumice stones of 1.0 cm×1.0 cm×1.0 cm and pumice stone/growth medium ratio of 1:5 were found to be the optimum conditions for successful immobilization of (90.0±1.6) % cells and production of (331.4±7.3) g/L acetylglucosamine. The highest acetylglucosamine concentration of (323.0±2.5) g/L was obtained in the first fermentation cycle, which then decreased and remained stable throughout the last three cycles.
NOVELTY AND SCIENTIFIC CONTRIBUTION
, a strong chitinolytic bacterium previously isolated from rotten shrimp shells, was used for the first time in immobilized form to produce acetylglucosamine. The findings in this research showed the potential use of cells immobilized in pumice stone for continuous production of acetylglucosamine in repeated fermentation.
PubMed: 35440879
DOI: 10.17113/ftb.60.01.22.6994 -
Frontiers in Psychiatry 2022
PubMed: 35308870
DOI: 10.3389/fpsyt.2022.837283 -
Biology Feb 2023Parasitoids are promising biocontrol agents of the devastating fruit fly, . However, parasitoid performance is a function of several factors, including host-associated...
Parasitoids are promising biocontrol agents of the devastating fruit fly, . However, parasitoid performance is a function of several factors, including host-associated symbiotic bacteria. , , and are among the symbiotic bacteria commonly associated with , and they influence the eco-physiological functioning of this pest. However, whether these bacteria influence the interaction between this pest and its parasitoids is unknown. This study sought to elucidate the nature of the interaction of the parasitoids, , , and with as mediated by symbiotic bacteria. Three types of fly lines were used: axenic, symbiotic, and bacteria-mono-associated (, , and ). The suitable stages of each fly line were exposed to the respective parasitoid species and reared until the emergence of adult flies/parasitoids. Thereafter, data on the emergence and parasitoid fitness traits were recorded. No wasps emerged from the fly lines exposed to . The highest emergence of . and was recorded in the fly lines. The parasitoid progeny from the and fly lines had the longest developmental time and the largest body size. Conversely, parasitoid fecundity was significantly lower in the lines, whereas the lines significantly improved fecundity. These results elucidate some effects of bacterial symbionts on host-parasitoid interactions and their potential in enhancing parasitoid-oriented management strategies against .
PubMed: 36829551
DOI: 10.3390/biology12020274 -
BMC Microbiology Oct 2023This study aimed to investigate the clinical infection characteristics and analyze the resistance gene carrying status of carbapenem-resistant Providencia rettgeri via...
OBJECTIVE
This study aimed to investigate the clinical infection characteristics and analyze the resistance gene carrying status of carbapenem-resistant Providencia rettgeri via whole genome sequencing (WGS).
METHODS
Carbapenem-resistant P. rettgeri were collected from clinical patients between January 2020 and December 2021, and their susceptibility to 19 antimicrobial drugs was determined using the VITEK 2 Compact system and Kirby-Bauer (KB) disk diffusion method. The Illumina platform was used to perform WGS of the P. rettgeri isolates, and the resistance genes carried by the Carbapenem-resistant P. rettgeri strains were detected via ABRicate software. The phylogenetic tree was constructed by thirty-four strains including twenty-eight strains downloaded from NCBI database and the carbapenem-resistant six P. rettgeri strains in this study. Which based on genomic single nucleotide polymorphism (SNP) to understand the affinities of the carbapenem-resistant P. rettgeri strains.
RESULTS
Six carbapenem-resistant P. rettgeri strains were isolated from five different clinical departments using the blood, urine, sputum, and secretion specimens. These infected patients are middle-aged and elderly people with a history of severe trauma, tumors, hypertension, and various other underlying diseases, and invasive procedures. Antimicrobial sensitivity testing showed that all strains presented resistance to ampicillin-sulbactam, ceftazidime, ciprofloxacin, levofloxacin, and ertapenem, whereas they exhibited full susceptibility to cefepime and amikacin. Most strains demonstrated high resistance to β-lactams, aminoglycosides, and sulfonamides. Thirty-five resistance genes were identified by ABRicate. All carbapenem-resistant P. rettgeri strains carried aminoglycoside, fluoroquinolone, chloramphenicol, rifampicin, sulfonamide, and β-lactam resistance genes, and most importantly, all strains possessed the carbapenem resistance gene bla. The six P. rettgeri strains in this study and the 28 carbapenem-resistant P. rettgeri strains from the NCBI database were divided into four evolutionary groups. The WF3643, WF3849, WF3822, and WF3821 strains in this study were in the same evolutionary group (clade A), while the closely related WF3099 and WF3279 strains were in different evolutionary groups (clade B and clade D), respectively. The WF3099 strain was distantly related to the other five strains.
CONCLUSION
Carbapenem-resistant P. rettgeri strains were mostly isolated from middle-aged and older patients with a history of surgery or serious underlying diseases, and they were found to cause multisystem infections. All Carbapenem-resistant P. rettgeri strains in this study carried bla and multiple antimicrobial drug resistance genes. Furthermore, the P. rettgeri strains in this study were closely related, suggesting the possibility of nosocomial infections. Therefore, our study highlights the need for research on P. rettgeri to control the spread of these nosocomial infections.
Topics: Middle Aged; Aged; Humans; beta-Lactamases; Phylogeny; Anti-Bacterial Agents; Carbapenems; Aminoglycosides; Whole Genome Sequencing; Cross Infection; Microbial Sensitivity Tests
PubMed: 37789331
DOI: 10.1186/s12866-023-03032-3 -
Journal of Insect Science (Online) May 2023Mexican fruit fly (Anastrepha ludens (Loew)) (Diptera: Tephritidae) represents a major threat to fruit production in the Western Hemisphere. Sterile insect technique is...
Mexican fruit fly (Anastrepha ludens (Loew)) (Diptera: Tephritidae) represents a major threat to fruit production in the Western Hemisphere. Sterile insect technique is used to suppress and eradicate wild populations. Success of this control method necessitates weekly production of hundreds of millions of flies, their sterilization by irradiation, and their aerial release. Diet needed to produce large fly numbers are conducive to the spread of bacteria. Pathogenic bacteria were isolated from 3 rearing facilities and from multiple sources: eggs, larvae, pupae and spent diet, and were found to include some isolates identified to the genus Providencia (Enterobacteriales: Morganellaceae). We identified 41 Providencia isolates and tested their pathogenicity to A. ludens. Based on 16s rRNA sequences, 3 groups were clustered into several species of Providencia with varying capacities to affect the Mexican fruit fly production. Isolates putatively identified as P. alcalifaciens/P. rustigianii were all pathogenic causing larval and pupal yield reduction of 46-64% and 37-57%, respectively. Among them, Providencia isolate 3006 was the most pathogenic reducing larval and pupae yield by 73 and 81%, respectively. Isolates identified as P. sneebia were not pathogenic. The final cluster, P. rettgeri/P. vermicola, were variable in pathogenicity with 3 isolates yielding like the control and the rest causing larval and pupal yield reduction of 26-53% and 23-51%, respectively. Isolates putatively identified as P. alcalifaciens/P. rustigianii were more virulent than P. rettgeri/P. vermicola. Accurate identification of species is needed to diagnose and monitor pathogenic versus nonpathogenic Providencia strains.
Topics: Animals; Tephritidae; Providencia; Virulence; RNA, Ribosomal, 16S; Ovum; Larva; Pupa
PubMed: 37220089
DOI: 10.1093/jisesa/iead024 -
The Journal of Antimicrobial... Jun 2019Our aim was to confirm with a large panel of clinical isolates that class 2 integrons are highly prevalent in Proteae and to analyse their genetic characteristics.
OBJECTIVES
Our aim was to confirm with a large panel of clinical isolates that class 2 integrons are highly prevalent in Proteae and to analyse their genetic characteristics.
METHODS
Proteae (Proteus spp., Morganella spp. and Providencia spp.) isolates were collected from clinical samples during 2013 at Limoges University Hospital, France. The presence of class 1, 2 and 3 integrons was investigated by quantitative PCR. The presence of a stop codon in the intI2 gene was determined by Sanger sequencing. The gene cassette arrays of class 2 integrons were determined by PCR-RFLP and Sanger sequencing or next-generation sequencing when needed.
RESULTS
Of the 327 Proteae collected, 103 (31.5%) harboured a class 2 integron and 45 (13.8%) a class 1 integron. No class 3 integrons were detected. One functional IntI2 integrase was detected in a Morganella morganii isolate. Six different gene cassette arrays were detected. Four had already been described in the literature: dfrA1-sat2-aadA1 (72 isolates), dfrA1-catB2-sat2-aadA1 (17), sat2-aadA1 (6) and lnu(F), dfrA1, aadA1 (1). We identified two new gene cassette arrays: (i) a new variant of the dfrA1 gene cassette (one isolate; the one with the functional IntI2); and (ii) the array dfrA1-gcu115-sat2 harbouring the new gcu115 gene cassette with two ORFs encoding proteins of unknown functions (five isolates).
CONCLUSIONS
We showed a high frequency of class 2 integrons, as well as a diversity of gene cassette arrays, among Proteae. This work highlights that the Proteae tribe plays an important role as a reservoir of class 2 integrons.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; France; Humans; Integrons; Morganella; Proteus; Providencia
PubMed: 30805633
DOI: 10.1093/jac/dkz079 -
JACC. Clinical Electrophysiology Dec 2021
Topics: Cardiac Conduction System Disease; Humans; Myotonic Dystrophy
PubMed: 34949430
DOI: 10.1016/j.jacep.2021.10.005 -
Journal of Infection in Developing... Jul 2022Radiology is a technical service that provides medical imaging for all sectors of healthcare. Hospital-acquired infections (HAIs) is a major challenge in radiology and...
INTRODUCTION
Radiology is a technical service that provides medical imaging for all sectors of healthcare. Hospital-acquired infections (HAIs) is a major challenge in radiology and this is exacerbated in contexts where the healthcare system is unable to provide adequate funding and attention to effective infection control measures. The objectives of this study were to audit current cleaning procedures through the observation of practices in a radiology department, and to determine the types and numbers of nosocomial pathogens present on selected radiology imaging equipment and accessories before and after decontamination.
METHODOLOGY
In phase one we observed seven radiographers to audit cleaning procedures and practices. In phase two we collected swab samples from selected radiology imaging equipment and accessories and then cultured them for identification of microbes.
RESULTS
It was observed that radiographers partially practiced infection control measures. This was due to the absence of documented protocol for infection control procedures. Our results indicated that all the selected equipment and accessories were contaminated with microorganisms pre- and post-cleaning. The identified microbes were Staphylococcus aureus, Coagulase negative Staphylococci (CoNS), Bacillus species (spp.), Shigella spp., Shigella sonnei., Klebsiella spp., Salmonella paratyphi A (S. paratyphi A), Salmonella typhi (S. typhi), Providencia rettgeri, Enterobacter spp. and Citrobacter spp. and Methicillin resistant strains of Staphylococcus aureus (MRSA).
CONCLUSIONS
The research concluded that the recommended cleaning agents did not effectively reduce the number of microorganisms making the selected equipment and accessories fomites for nosocomial pathogens.
Topics: Cross Infection; Equipment Contamination; Fomites; Hospitals; Humans; Methicillin-Resistant Staphylococcus aureus; Radiology; Staphylococcal Infections
PubMed: 35905022
DOI: 10.3855/jidc.14225 -
Journal of Veterinary Internal Medicine Sep 2021A severe form of acute hemorrhagic diarrhea syndrome (AHDS) occurred in dogs in the Oslo region of Norway during autumn 2019.
BACKGROUND
A severe form of acute hemorrhagic diarrhea syndrome (AHDS) occurred in dogs in the Oslo region of Norway during autumn 2019.
OBJECTIVES
To characterize the fecal microbiota of dogs with AHDS during the outbreak and compare it to that of healthy dogs from the same period and before the outbreak.
ANIMALS
Dogs with AHDS (n = 50), dogs with nonhemorrhagic diarrhea (n = 3), and healthy dogs (n = 11) were sampled during the outbreak. In addition, 78 healthy dogs from the same region were sampled before the outbreak between 2017 and 2018.
METHODS
Retrospective case-control study. The fecal microbiotas were characterized using 16S rRNA gene amplicon sequencing.
RESULTS
Dogs with AHDS had significantly different microbiota composition (R = .07, P < .001) and decreased intestinal diversity relative to healthy dogs from the outbreak period (median, 2.7; range, 0.9-3.5 vs median, 3.2; range, 2.6-4.0; P < .001). The microbiota in dogs with AHDS was characterized by a decrease of Firmicutes and an outgrowth of Proteobacteria, with increased numbers of Clostridium perfringens and Providencia spp. Among the Providencia spp., 1 showed 100% sequence identity with a Providencia alcalifaciens strain that was cultivated and isolated from the same outbreak. No Providencia spp. was found in healthy dogs sampled before the outbreak.
CONCLUSIONS AND CLINICAL IMPORTANCE
Dogs with AHDS had marked changes in fecal microbiota including increased numbers of Providencia spp. and C. perfringens, which may have contributed to the severity of this illness.
Topics: Animals; Case-Control Studies; Diarrhea; Disease Outbreaks; Dog Diseases; Dogs; Feces; Microbiota; Providencia; RNA, Ribosomal, 16S; Retrospective Studies
PubMed: 34288148
DOI: 10.1111/jvim.16201 -
Pathogens (Basel, Switzerland) Sep 2023Bloodstream infections associated with AmpC-producing Enterobacterales are severe medical conditions which, without prompt and effective treatment, may have dire...
Bloodstream infections associated with AmpC-producing Enterobacterales are severe medical conditions which, without prompt and effective treatment, may have dire ramifications. This study aimed to assess whether certain comorbidities and previous surgical procedures coincide with resistance determinants of AmpC-producing Enterobacterales associated with bloodstream infections. Antibiotic resistance patterns and therapy outcome were also determined. The patients' data obtained revealed that the prevalence of recent surgical procedures, solid organ tumors, metabolic diseases, kidney and liver failure, and hematological malignancies do not differ between resistant and susceptible isolates of AmpC-producing Enterobacterales. Furthermore, no difference was reported in mortality rates. Regarding antibiotic resistance, 34.52% of isolates were confirmed to be resistant (AmpC hyperproduction, ESBL, or carbapenemase). More than one in five AmpC hyperproducers were reported amid spp., , , and strains. Carbapenemases were mostly noted in spp. followed by and strains. had the highest proportion of ESBLsof ESBLs. Resistance to expanded-spectrum cephalosporins of spp. and strains exceeded 50%, and resistance to meropenem over 10% was observed only in strains. Enterobacterales' ever-growing resistance to antibiotics is becoming quite a challenge for clinicians and new treatment options are required.
PubMed: 37764933
DOI: 10.3390/pathogens12091125