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Frontiers in Nutrition 2022Restrictive diets for the treatment of different gastrointestinal disorders are reported to change the composition of intestinal microbiota. Recently, it has been...
The dietary treatment of histamine intolerance reduces the abundance of some histamine-secreting bacteria of the gut microbiota in histamine intolerant women. A pilot study.
Restrictive diets for the treatment of different gastrointestinal disorders are reported to change the composition of intestinal microbiota. Recently, it has been proposed that individuals with histamine intolerance suffer from intestinal dysbiosis, having an overabundance of histamine-secreting bacteria, but how it is still unknown this state is affected by the usual dietary treatment of histamine intolerance [i.e., low-histamine diet and the supplementation with diamine oxidase (DAO) enzyme]. Thus, a preliminary study was carried out aiming to evaluate the potential changes on the composition of the intestinal microbiota in a group of five women diagnosed with histamine intolerance undergoing 9 months of the dietary treatment of histamine intolerance. After sequencing bacterial 16S rRNA genes (V3-V4 region) and analyzing the data using the EzBioCloud Database, we observed a reduction in certain histamine-secreting bacteria, including the genera and and the specie . Moreover, it was also observed an increase in spp., a bacterial group frequently related to gut health. These changes could help to explain the clinical improvement experienced by histamine intolerant women underwent a dietary treatment.
PubMed: 36337620
DOI: 10.3389/fnut.2022.1018463 -
Critical Reviews in Microbiology Mar 2019Polymyxins are important lipopeptide antibiotics that serve as the last-line defense against multidrug-resistant (MDR) Gram-negative bacterial infections. Worryingly,... (Review)
Review
Polymyxins are important lipopeptide antibiotics that serve as the last-line defense against multidrug-resistant (MDR) Gram-negative bacterial infections. Worryingly, the clinical utility of polymyxins is currently facing a serious threat with the global dissemination of , plasmid-mediated polymyxin resistance. The first plasmid-mediated polymyxin resistance gene, termed as was identified in China in November 2015. Following its discovery, isolates carrying , mainly and less commonly to , have been reported across Asia, Africa, Europe, North America, South America and Oceania. This review covers the epidemiological, microbiological and genomics aspects of this emerging threat to global human health. The has been identified in various species of Gram-negative bacteria including , , , , , , , , , , , and species from animal, meat, food product, environment and human sources. More alarmingly is the detection of in extended-spectrum-β-lactamases- and carbapenemases-producing bacteria. The can be carried by different plasmids, demonstrating the high diversity of plasmid reservoirs. Our review analyses the current knowledge on the emergence of -mediated polymyxin resistance.
Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Drug Resistance, Bacterial; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Humans; Plasmids; Polymyxins; Transferases (Other Substituted Phosphate Groups)
PubMed: 31122100
DOI: 10.1080/1040841X.2018.1492902 -
Diagnostic Microbiology and Infectious... Jun 2023A total of 35,360 Enterobacterales isolates were consecutively collected from 75 US medical centers in 2018-2022. Among these isolates, 2612 (7.4%) were categorized as...
Ceftazidime-avibactam, meropenem-vaborbactam, and imipenem-relebactam activities against multidrug-resistant Enterobacterales from United States Medical Centers (2018-2022).
A total of 35,360 Enterobacterales isolates were consecutively collected from 75 US medical centers in 2018-2022. Among these isolates, 2612 (7.4%) were categorized as multidrug-resistant (MDR). Isolates were susceptibility tested by reference broth microdilution methods. Carbapenem-resistant Enterobacterales (CRE) were screened for carbapenemase (CPE) genes by whole genome sequencing. The highest MDR rates was observed among Klebsiella pneumoniae (12.2%), followed by Raoultella spp. (10.9%) and Providencia stuartii (9.8%). Ceftazidime-avibactam and meropenem-vaborbactam were very active and showed identical susceptibility rates against MDR isolates (97.9%). Imipenem-relebactam (93.5% susceptible [S]) exhibited slightly lower susceptibility rates due to its limited activity against Morganellaceae family. The most active β-lactamase inhibitor combination (BLI) against CRE isolates (n = 310) was ceftazidime-avibactam (84.2%S), followed by meropenem-vaborbactam (81.9%S) and imipenem-relebactam (74.8%S). All 3 BLIs were very active against KPC producers and none were active against MBL producers. Ceftazidime-avibactam exhibited greater activity against OXA-48-type producers than meropenem-vaborbactam and imipenem-vaborbactam.
Topics: United States; Humans; Meropenem; Anti-Bacterial Agents; Ceftazidime; Azabicyclo Compounds; Drug Combinations; Imipenem; beta-Lactamases; Carbapenems; Microbial Sensitivity Tests
PubMed: 37060707
DOI: 10.1016/j.diagmicrobio.2023.115945 -
Antimicrobial Resistance and Infection... Jun 2022Sepsis due to multidrug resistant (MDR) bacteria is a growing public health problem mainly in low-income countries.
BACKGROUND
Sepsis due to multidrug resistant (MDR) bacteria is a growing public health problem mainly in low-income countries.
METHODS
A multicenter study was conducted between October 2019 and September 2020 at four hospitals located in central (Tikur Anbessa and Yekatit 12), southern (Hawassa) and northern (Dessie) parts of Ethiopia. A total of 1416 patients clinically investigated for sepsis were enrolled. The number of patients from Tikur Anbessa, Yekatit 12, Dessie and Hawassa hospital was 501, 298, 301 and 316, respectively. At each study site, blood culture was performed from all patients and positive cultures were characterized by their 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). Antimicrobial resistance pattern of bacteria was determined by disc diffusion. Logistic regression analysis was used to assess associations of dependent and independent variables. A p-value < 0.05 was considered as statistically significant. The data was analyzed using SPSS version 25.
RESULTS
Among 1416 blood cultures performed, 40.6% yielded growth. Among these, 27.2%, 0.3% and 13.1%, were positive for pathogenic bacteria, yeast cells and possible contaminants respectively. Klebsiella pneumoniae (26.1%), Klebsiella variicola (18.1%) and E. coli (12.4%) were the most frequent. Most K. variicola were detected at Dessie (61%) and Hawassa (36.4%). Almost all Pantoea dispersa (95.2%) were isolated at Dessie. Rare isolates (0.5% or 0.2% each) included Leclercia adecarboxylata, Raoultella ornithinolytica, Stenotrophomonas maltophilia, Achromobacter xylosoxidans, Burkholderia cepacia, Kosakonia cowanii and Lelliottia amnigena. Enterobacteriaceae most often showed resistance to ampicillin (96.2%), ceftriaxone (78.3%), cefotaxime (78%), cefuroxime (78%) and ceftazidime (76.4%). MDR frequency of Enterobacteriaceae at Hawassa, Tikur Anbessa, Yekatit 12 and Dessie hospital was 95.1%, 93.2%, 87.3% and 67.7%, respectively. Carbapenem resistance was detected in 17.1% of K. pneumoniae (n = 111), 27.7% of E. cloacae (n = 22) and 58.8% of Acinetobacter baumannii (n = 34).
CONCLUSION
Diverse and emerging gram-negative bacterial etiologies of sepsis were identified. High multidrug resistance frequency was detected. Both on sepsis etiology types and MDR frequencies, substantial variation between hospitals was determined. Strategies to control MDR should be adapted to specific hospitals. Standard bacteriological services capable of monitoring emerging drug-resistant sepsis etiologies are essential for effective antimicrobial stewardship.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Escherichia coli; Ethiopia; Hospitals; Humans; Klebsiella pneumoniae; Microbial Sensitivity Tests; Referral and Consultation; Sepsis
PubMed: 35698179
DOI: 10.1186/s13756-022-01122-x -
Cureus Sep 2021is a gram-negative, aerobic, nonmotile bacteria that can be found in soil and water. This is a relatively rare organism with few case reports on it and only three...
is a gram-negative, aerobic, nonmotile bacteria that can be found in soil and water. This is a relatively rare organism with few case reports on it and only three reports of -induced urinary tract infection (UTI) have been reported. Here we present a case of acute cystitis caused by in a woman with atrial fibrillation and recurrent UTIs.
PubMed: 34660160
DOI: 10.7759/cureus.17985 -
Frontiers in Microbiology 2024Seventeen Gram-negative, facultatively anaerobic bacterial strains were isolated from bleeding cankers of various broadleaf hosts and oak rhizosphere soil in Great...
Seventeen Gram-negative, facultatively anaerobic bacterial strains were isolated from bleeding cankers of various broadleaf hosts and oak rhizosphere soil in Great Britain. The strains were tentatively identified as belonging to the genus based on 16S rRNA gene sequencing. Multilocus sequence analysis (MLSA), based on four protein-encoding genes (, , , and ), separated the strains into three clusters within the genus clade. The majority of strains clustered with the type strain of , with the remaining strains divided into two clusters with no known type strain. Whole genome sequencing comparisons confirmed these two clusters of strains as belonging to two novel species which can be differentiated phenotypically from their current closest phylogenetic relatives. Therefore, two novel species are proposed: sp. nov. (type strain = BAC 10a-01-01 = LMG 33072 = CCUG 77096) and sp. nov. (type strain = TW_WC1a.1 = LMG 33073 = CCUG 77094).
PubMed: 38756725
DOI: 10.3389/fmicb.2024.1386923 -
PloS One 2015A total of 1135 carbapenem-resistant (nonsusceptible) Enterobacteriaceae (CRE) isolates were recovered between November 2010 and July 2012 (517 from 2010-2011 and 618...
A total of 1135 carbapenem-resistant (nonsusceptible) Enterobacteriaceae (CRE) isolates were recovered between November 2010 and July 2012 (517 from 2010-2011 and 618 from 2012) from 4 hospitals in Taiwan. Carbapenemase-producing Enterobacteriaceae (CPE) comprised 5.0% (57 isolates), including 17 KPC-2 (16 Klebsiella pneumoniae and 1 Escherichia coli), 1 NDM-1 (K. oxytoca), 37 IMP-8 (26 Enterobacter cloacae, 4 Citrobacter freundii, 4 Raoultella planticola, 1 K. pneumoniae, 1 E. coli and 1 K. oxytoca), and 2 VIM-1 (1 E. cloacae, 1 E. coli). The KPC-2-positive K. pneumoniae were highly clonal even in isolates from different hospitals, and all were ST11. IMP-8 positive E. cloacae from the same hospitals showed higher similarity in PFGE pattern than those from different hospitals. A total of 518 CRE isolates (45.6%) were positive for blaESBL, while 704 (62.0%) isolates were blaAmpC-positive, 382 (33.6% overall) of which carried both blaESBL and blaAmpC. CTX-M (414, 80.0%) was the most common blaESBL, while DHA (497, 70.6%) and CMY (157, 22.3%) were the most common blaAmpC. Co-carriage of blaESBL and blaAmpC was detected in 31 (54.4%) and 15 (26.3%) of the 57 CPE, respectively. KPC-2 was the most common carbapenemase detected in K. pneumoniae (2.8%), while IMP-8 was the most common in E. cloacae (9.7%). All KPC-2-positive CRE were resistant to all three tested carbapenems. However, fourteen of the 37 IMP-8-positive CRE were susceptible to both imipenem and meropenem in vitro. Intra- and inter-hospital spread of KPC-2-producing K. pneumoniae and IMP-8-producing E. cloacae likely occurred. Although the prevalence of CPE is still low, careful monitoring is urgently needed. Non-susceptibility to ertapenem might need to be considered as one criterion of definition for CRE in areas where IMP type carbapenemase is prevalent.
Topics: Anti-Infective Agents; Carbapenems; Drug Resistance, Bacterial; Enterobacteriaceae; Enterobacteriaceae Infections; Genes, Bacterial; Hospitals; Humans; Microbial Sensitivity Tests; Phylogeny; Prevalence; Species Specificity; Taiwan; beta-Lactamases
PubMed: 25794144
DOI: 10.1371/journal.pone.0121668 -
Antimicrobial Agents and Chemotherapy Jan 2004Enterobacterial strains of Raoultella spp. display a penicillinase-related beta-lactam resistance pattern suggesting the presence of a chromosomal bla gene. From...
Enterobacterial strains of Raoultella spp. display a penicillinase-related beta-lactam resistance pattern suggesting the presence of a chromosomal bla gene. From whole-cell DNA of Raoultella planticola strain ATCC 33531(T) and Raoultella ornithinolytica strain ATCC 31898(T), bla genes were cloned and expressed into Escherichia coli. Each gene encoded an Ambler class A beta-lactamase, named PLA-1 and ORN-1 for R. planticola and R. ornithinolytica, respectively. These beta-lactamases (291 amino acids), with the same pI value of 7.8, had a shared amino acid identity of 94%, 37 to 47% identity with the majority of the chromosome-encoded class A beta-lactamases previously described for Enterobacteriaceae, and 66 to 69% identity with the two beta-lactamases LEN-1 and SHV-1 from Klebsiella pneumoniae. However, the highest identity percentage (69 to 71%) was found with the plasmid-mediated beta-lactamase TEM-1. PLA-1, which displayed very strong hydrolytic activity against penicillins, also displayed significant hydrolytic activity against cefepime and, to a lesser extent, against cefotaxime and aztreonam, but there was no hydrolytic activity against ceftazidime. Such a substrate profile suggests that the Raoultella beta-lactamases PLA-1 and ORN-1 should be classified into the group 2be of the beta-lactamase classification of K. Bush, G. A. Jacoby, and A. A. Medeiros (Antimicrob. Agents Chemother. 39:1211-1233, 1995). The highly homologous regions upstream of the bla(PLA-1A) and bla(ORN-1A) genes comprised a nucleotide sequence identical to the -35 region and another one very close to the -10 region of the bla(LEN-1) gene. From now on, as the bla gene sequences of the most frequent Raoultella and Klebsiella species are available, the bla gene amplification method can be used to differentiate these species from each other, which the biochemical tests currently carried out in the clinical laboratory are unable to do.
Topics: Amino Acid Sequence; Anti-Bacterial Agents; Cloning, Molecular; DNA, Bacterial; Enterobacteriaceae; Isoelectric Focusing; Microbial Sensitivity Tests; Molecular Sequence Data; Plasmids; beta-Lactamases; beta-Lactams
PubMed: 14693555
DOI: 10.1128/AAC.48.1.305-312.2004 -
Antibiotics (Basel, Switzerland) Jun 2023Mobile colistin resistance () genes (-1 to -10) are plasmid-encoded genes that threaten the clinical utility of colistin (COL), one of the highest-priority critically... (Review)
Review
Mobile Colistin Resistance () Gene-Containing Organisms in Poultry Sector in Low- and Middle-Income Countries: Epidemiology, Characteristics, and One Health Control Strategies.
Mobile colistin resistance () genes (-1 to -10) are plasmid-encoded genes that threaten the clinical utility of colistin (COL), one of the highest-priority critically important antibiotics (HP-CIAs) used to treat infections caused by multidrug-resistant and extensively drug-resistant bacteria in humans and animals. For more than six decades, COL has been used largely unregulated in the poultry sector in low- and middle-income countries (LMICs), and this has led to the development/spread of gene-containing bacteria (MGCB). The prevalence rates of -positive organisms from the poultry sector in LMICs between January 1970 and May 2023 range between 0.51% and 58.8%. Through horizontal gene transfer, conjugative plasmids possessing insertion sequences (ISs) (especially IS), transposons (predominantly Tn), and integrons have enhanced the spread of -1, -2, -3, -4, -5, -7, -8, -9, and -10 in the poultry sector in LMICs. These genes are harboured by , , , , , , , , , , , , and species, belonging to diverse clones. The -1, -3, and -10 genes have also been integrated into the chromosomes of these bacteria and are mobilizable by ISs and integrative conjugative elements. These bacteria often coexpress with virulence genes and other genes conferring resistance to HP-CIAs, such as extended-spectrum cephalosporins, carbapenems, fosfomycin, fluoroquinolone, and tigecycline. The transmission routes and dynamics of MGCB from the poultry sector in LMICs within the One Health triad include contact with poultry birds, feed/drinking water, manure, poultry farmers and their farm workwear, farming equipment, the consumption and sale of contaminated poultry meat/egg and associated products, etc. The use of pre/probiotics and other non-antimicrobial alternatives in the raising of birds, the judicious use of non-critically important antibiotics for therapy, the banning of nontherapeutic COL use, improved vaccination, biosecurity, hand hygiene and sanitization, the development of rapid diagnostic test kits, and the intensified surveillance of genes, among others, could effectively control the spread of MGCB from the poultry sector in LMICs.
PubMed: 37508213
DOI: 10.3390/antibiotics12071117 -
Frontiers in Microbiology 2022A two-way relationship between diabetes and periodontitis has been discussed recently. Periodontitis microbiota might affect the immune homeostasis of diabetes, but the...
A two-way relationship between diabetes and periodontitis has been discussed recently. Periodontitis microbiota might affect the immune homeostasis of diabetes, but the molecular mechanism of their interactions is still not clear. The aims of this study were to clarify the possible immune regulatory effects of periodontitis microbiota on diabetes and the correlation between immunomodulation and ectopic colonization. A model of germ-free mice with streptozotocin-induced type 1 diabetes mellitus (T1D), which was orally inoculated with mixed saliva samples for 2 weeks, was used in this study. Those mice were randomly divided into two groups, namely, SP (where the T1D mice were orally inoculated with mixed saliva samples from periodontitis patients) and SH (where the T1D mice were orally inoculated with mixed saliva samples from healthy subjects). Ectopic colonization of saliva microbiota was assessed using culture-dependent method and Sanger sequencing, and the composition of gut microbiota was analyzed using 16S rRNA gene sequencing. Changes in 15 types of immune cells and six cytokines either from the small intestine or spleen were detected by multicolor flow cytometry. The correlation between gut microbiota and immune cells was evaluated by redundancy analysis. Although periodontitis microbiota minorly colonized the lungs, spleens, and blood system, they predominantly colonized the gut, which was mainly invaded by . SH and SP differed in beta diversity of the gut bacterial community. Compared to SH, microbial alteration in small intestine occurred with an increase of , , , , and a decrease of in SP. More types of immune cells were disordered in the spleen than in the small intestine by periodontitis microbiota, mainly with a dramatical increase in the proportion of macrophages, plasmacytoid dendritic cells (pDCs), monocytes, group 3 innate lymphoid cells, CD4-CD8- T cells and Th17 cells, as well as a decline of αβT cells in SP. Cytokines of IFNγ, IL17, and IL22 produced by CD4 + T cells as well as IL22 produced by ILCs of small intestine rose in numbers, and the intestinal and splenic pDCs were positively regulated by gut bacterial community in SP. In conclusion, periodontitis microbiota invasion leads to ectopic colonization of the extra-oral sites and immune cells infiltration, which might cause local or systemic inflammation. Those cells are considered to act as a "bridge" between T1D and periodontitis.
PubMed: 35756043
DOI: 10.3389/fmicb.2022.889415