-
Frontiers in Microbiology 2021Plasmids carrying metal resistance genes (MRGs) have been suggested to be key ecological players in the adaptation of metal-impacted microbial communities, making them...
Plasmids carrying metal resistance genes (MRGs) have been suggested to be key ecological players in the adaptation of metal-impacted microbial communities, making them promising drivers of bio-remediation processes. However, the impact of metals on plasmid-mediated spread of MRGs through selection, plasmid loss, and transfer is far from being fully understood. In the present study, we used two-member bacterial communities to test the impact of lead on the dispersal of the IncP plasmid pKJK5 from a KT2440 plasmid donor and two distinct recipients, B4 or SPH-1 after 4 and 10 days of mating. Two versions of the plasmid were used, carrying or not carrying the lead resistance TRABCD operon, to assess the importance of fitness benefit and conjugative potential for the dispersal of the plasmid. The spread dynamics of metal resistance conveyed by the conjugative plasmid were dependent on the recipient and the lead concentration: For , the operon did not facilitate neither lead resistance nor variation in plasmid spread. The growth gain brought by the operon to SPH-1 and KT2440 at 1 mM Pb enhanced the spread of the plasmid. At 1.5 mM Pb after 4 days, the proteomics results revealed an oxidative stress response and an increased abundance of pKJK5-encoded conjugation and partitioning proteins, which most likely increased the transfer of the control plasmid to SPH-1 and ensured plasmid maintenance. As a consequence, we observed an increased spread of pKJK5-. Conversely, the operon reduced the oxidative stress response and impeded the rise of conjugation- and partitioning-associated proteins, which slowed down the spread of the carrying plasmid. Ultimately, when a fitness gain was recorded in the recipient strain, the spread of MRG-carrying plasmids was facilitated through positive selection at an intermediate metal concentration, while a high lead concentration induced oxidative stress with positive impacts on proteins encoding plasmid conjugation and partitioning.
PubMed: 34122370
DOI: 10.3389/fmicb.2021.655903 -
Parasitology Research Jan 2017Pathogenic free-living amoebae (FLA), such as Naegleria fowleri, Balamuthia mandrillaris and Acanthamoeba species isolated from aquatic environments have been implicated...
Pathogenic free-living amoebae (FLA), such as Naegleria fowleri, Balamuthia mandrillaris and Acanthamoeba species isolated from aquatic environments have been implicated in central nervous system, eye and skin human infections. They also allow the survival, growth and transmission of bacteria such as Legionella, Mycobacteria and Vibrio species in water systems. The purpose of this study was to investigate the co-occurrence of potentially pathogenic FLA and their associated bacteria in hospital water networks in Johannesburg, South Africa. A total of 178 water (n = 95) and swab (n = 83) samples were collected from two hospital water distribution systems. FLA were isolated using the amoebal enrichment technique and identified using PCR and 18S rDNA sequencing. Amoebae potentially containing intra-amoebal bacteria were lysed and cultured on blood agar plates. Bacterial isolates were characterized using the VITEK®2 compact System. Free-living amoebae were isolated from 77 (43.3 %) of the samples. Using microscopy, PCR and 18S rRNA sequencing, Acanthamoeba spp. (T3 and T20 genotypes), Vermamoeba vermiformis and Naegleria gruberi specie were identified. The Acanthamoeba T3 and T20 genotypes have been implicated in eye and central nervous system infections. The most commonly detected bacterial species were Serratia marcescens, Stenotrophomonas maltophilia, Delftia acidovorans, Sphingomonas paucimobilis and Comamonas testosteroni. These nosocomial pathogenic bacteria are associated with systematic blood, respiratory tract, the urinary tract, surgical wounds and soft tissues infections. The detection of FLA and their associated opportunistic bacteria in the hospital water systems point out to a potential health risk to immune-compromised individuals.
Topics: Amoeba; Bacteria; Cross Infection; Fresh Water; Hospitals; Humans; South Africa
PubMed: 27730363
DOI: 10.1007/s00436-016-5271-3 -
Journal of Global Infectious Diseases 2023is an aerobic, nonfermentative Gram-negative bacillus infrequently isolated from clinical specimens. The pathogenicity and clinical significance of the organism has not...
is an aerobic, nonfermentative Gram-negative bacillus infrequently isolated from clinical specimens. The pathogenicity and clinical significance of the organism has not been ascertained due to uncommon clinical isolation and suspected low virulence. The organism has been reported to be inherently resistant to aminoglycoside group of drugs which remain as a widely used first-line drug of choice for febrile neutropenic patients. Hereby, we report a case of associated pleural effusion in a patient of metastatic adenocarcinoma diagnosed and treated timely and successfully with appropriate antibiotics.
PubMed: 37800087
DOI: 10.4103/jgid.jgid_66_22 -
Clinical & Experimental Optometry Jul 2017Because corneal infiltrative events (CIEs) may result from bacterial components on contact lenses, which can come from contaminated lens cases, we evaluated the biocidal...
BACKGROUND
Because corneal infiltrative events (CIEs) may result from bacterial components on contact lenses, which can come from contaminated lens cases, we evaluated the biocidal efficacy of five multipurpose solutions against Gram-negative commonly isolated and CIE-associated organisms.
METHODS
Of the multipurpose solutions tested, one contained polyhexamethylene biguanide (PHMB)/polyquaternium-1 (PQ-1; Bausch & Lomb Incorporated: Biotrue), one contained alexidine dihydrochloride (alexidine)/PQ-1 (AMO: RevitaLens OcuTec) and three contained PQ-1/myristamidopropyl dimethylamine (MAPD; Alcon: Opti-Free PureMoist, PQ-1/MAPD-1; Opti-Free RepleniSH, PQ-1/MAPD-2; Opti-Free Express, PQ-1/MAPD-3). Challenge organisms were CIE-associated Achromobacter xylosoxidans, Delftia acidovorans and Stenotrophomonas maltophilia at manufacturer-recommended durations (stand-alone), in lens cases without lenses (up to seven days) and in lens cases with etafilcon A lenses (up to 30 days).
RESULTS
In stand-alone testing against CIE-associated organisms, PHMB/PQ-1 and alexidine/PQ-1 were significantly superior versus MAPD-based multipurpose solutions against A. xylosoxidans (all p ≤ 0.01), D. acidovorans (all p ≤ 0.001) and S. maltophilia (all p ≤ 0.05). In lens cases, PHMB/PQ-1 and alexidine/PQ-1 achieved greater than 3-log reductions against all challenge organisms at all times evaluated. PQ-1/MAPD-1 achieved a greater than 3-log reduction against D. acidovorans at 24 hours; PQ-1/MAPD-1 and PQ-1/MAPD-3 achieved greater than 3-log reductions at seven days against all organisms. In lens cases with lenses, PHMB/PQ-1 and alexidine/PQ-1 achieved greater than 3-log reductions against all organisms at all times. PQ-1/MAPD-1 and PQ-1/MAPD-3 achieved greater than 3-log reductions at seven or more days against all organisms. PQ-1/MAPD-2 did not achieve a greater than 3-log reduction at any time; some regrowth was observed.
CONCLUSIONS
PHMB- and alexidine-based multipurpose solutions demonstrated significantly greater biocidal activity compared with PQ-1/MAPD-based agents against Gram-negative organisms commonly isolated and CIE-associated pathogens.
Topics: Contact Lens Solutions; Contact Lenses; Cornea; Corneal Diseases; Eye Infections, Bacterial; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Humans
PubMed: 28194876
DOI: 10.1111/cxo.12509 -
New Microbes and New Infections Sep 2020Multiple studies have established the contamination of hospital sinks and transmission to hospital personnel. Few studies have assessed the contamination and...
Multiple studies have established the contamination of hospital sinks and transmission to hospital personnel. Few studies have assessed the contamination and transmission of microorganisms from the faucets of operating bay scrub sinks to operating room (OR) personnel, a potential route of infection for patients. This study aimed to investigate if there was pathogenic contamination of scrub sinks and possible transmission of those pathogens to the hands of OR personnel after preoperative hand disinfection. Swabs were taken from the hands of 50 OR personnel and from the faucets of 24 scrubs sinks at two different hospital sites, and were cultured. Hands were swabbed after completing a surgical hand scrub. Results were reported in colony-forming units per millilitre. There was significant scrub sink contamination with primarily Gram-negative organisms, such as and . There was no overlap in bacterial species between the cultures from hands and scrub sinks. Cultures from the sinks and the hands of the OR personnel from one site had significantly higher bacterial growth compared with the other site (p < 0.0001 and p < 0.0118, respectively). The data showed significant contamination on the faucets of operating bay scrub sinks. However, there was no observed transmission of pathogens from the scrub sinks to OR personnel, shown by the lack of overlap in bacterial species. Routine hygienic maintenance of scrub sinks is recommended.
PubMed: 32995014
DOI: 10.1016/j.nmni.2020.100754 -
Genome Announcements Sep 2014The Delftia acidovorans 2167 (ATCC 15668, Delftia type strain) genome was sequenced into a 6-contig scaffolded assembly of 6.78-Mb. This environmental microbe,...
The Delftia acidovorans 2167 (ATCC 15668, Delftia type strain) genome was sequenced into a 6-contig scaffolded assembly of 6.78-Mb. This environmental microbe, previously named to both the Comamonas and Pseudomonas genera, is an opportunistic pathogen and often the subject of phylogenetic placement debates.
PubMed: 25237026
DOI: 10.1128/genomeA.00917-14 -
Animals : An Open Access Journal From... Dec 2023The present study was carried out to determine the seminal microbiota of boars and their correlation with sperm quality. A total of 17 ejaculates were collected from 17...
The present study was carried out to determine the seminal microbiota of boars and their correlation with sperm quality. A total of 17 ejaculates were collected from 17 Duroc boars and were classified according to sperm quality into two groups: low-quality ( = 8) and high-quality ( = 9). Each ejaculate was subjected to (i) semen evaluation, (ii) bacterial culture and MALDI-TOF identification, and (iii) 16S rRNA gene sequencing and bioinformatic analyses. No difference in the total bacterial count, alpha diversity, and beta diversity between the high-quality group and the low-quality group was detected ( > 0.05). While was negatively correlated with sperm quality ( < 0.05), was positively correlated with sperm quality ( < 0.05). Lactobacillales (25.2%; LB) and Enterobacterales (10.3%; EB) were the most dominant bacteria and negatively correlated: EB = 507.3 - 0.5 × LB, R = 0.24, < 0.001. Moreover, the abundance of was negatively correlated with LB (r = -0.754, < 0.001) and positively correlated with (r = 0.533, < 0.05). was positively correlated with (r = 0.485, < 0.05), (r = 0.622, < 0.01), and (r = 0.489, < 0.05). In conclusion, seminal microbiota is significantly associated with boar semen qualities. The distributions of the most dominant bacterial genera, the differences in the abundance of small subset microbes, and their correlation appear to have far more impact than the overall seminal bacterial content (e.g., total bacterial count, alpha diversity, and beta diversity) on sperm quality.
PubMed: 38136874
DOI: 10.3390/ani13243837 -
Respiratory Medicine Case Reports 2019Septic pulmonary emboli is a rare condition due to the dislodgement of an infected thrombus traveling to the pulmonary vasculature via the venous system. Staphylococcus...
Septic pulmonary emboli is a rare condition due to the dislodgement of an infected thrombus traveling to the pulmonary vasculature via the venous system. Staphylococcus spp. and Candida spp. are the most common causative agents. The most common risk factor is intravenous drug abuse, but there has been an association with intravenous catheters. Delftia acidovorans (DA) is a rare organism causing catheter-related infection, which has a tendency to embolize and clog up major vessels. It is highly resistant to all available aminoglycoside agents. There are only a few cases reported in children showing DA as a cause of septic emboli with none of the cases reported in a young patient. We report a similar case but in a young adult who developed septic emboli due to DA that was caused by an infected peripherally inserted central catheter (PICC) line. Since the organism is highly susceptible to recurrent embolization, the PICC line was removed and the patient was treated successfully with an appropriate antibiotic regime.
PubMed: 31011526
DOI: 10.1016/j.rmcr.2019.100835 -
Microbiology Resource Announcements Nov 2021Delftia acidovorans strain D4B is an aerobic bacterium within the lineage that was isolated from soil. The genome size is 6.26 Mbp, with a G+C content of 67%. The...
Delftia acidovorans strain D4B is an aerobic bacterium within the lineage that was isolated from soil. The genome size is 6.26 Mbp, with a G+C content of 67%. The genome encodes enzymes potentially involved in the degradation of fluorinated compounds.
PubMed: 34734765
DOI: 10.1128/MRA.00635-21 -
Microbiology (Reading, England) Jan 2008The utilization of organosulfonates as carbon sources by aerobic or nitrate-reducing bacteria usually involves a measurable, uncharacterized sulfite dehydrogenase. This...
The utilization of organosulfonates as carbon sources by aerobic or nitrate-reducing bacteria usually involves a measurable, uncharacterized sulfite dehydrogenase. This is tacitly assumed to be sulfite : ferricytochrome-c oxidoreductase [EC 1.8.2.1], despite negligible interaction with (eukaryotic) cytochrome c: the enzyme is assayed at high specific activity with ferricyanide as electron acceptor. Purified periplasmic sulfite dehydrogenases (SorAB, SoxCD) are known from chemoautotrophic growth and are termed 'sulfite oxidases' by bioinformatic services. The catalytic unit (SorA, SoxC; termed 'sulfite oxidases' cd02114 and cd02113, respectively) binds a molybdenum-cofactor (Moco), and involves a cytochrome c (SorB, SoxD) as electron acceptor. The genomes of several bacteria that express a sulfite dehydrogenase during heterotrophic growth contain neither sorAB nor soxCD genes; others contain at least four paralogues, for example Cupriavidus necator H16, which is known to express an inducible sulfite dehydrogenase during growth with taurine (2-aminoethanesulfonate). This soluble enzyme was enriched 320-fold in four steps. The 40 kDa protein (denatured) had an N-terminal amino acid sequence which started at position 42 of the deduced sequence of H16_B0860 (termed 'sulfite oxidase' cd02114), which we named SorA. The neighbouring gene is an orthologue of sorB, and the sorAB genes were co-transcribed. Cell fractionation showed SorA to be periplasmic. The corresponding enzyme in Delftia acidovorans SPH-1 was enriched 270-fold, identified as Daci_0055 (termed 'sulfite oxidase' cd02110) and has a cytochrome c encoded downstream. We presume, from genomic data for bacteria and archaea, that there are several subgroups of sulfite dehydrogenases, which all contain a Moco, and transfer electrons to a specific cytochrome c.
Topics: Bacterial Proteins; Cell Fractionation; Cupriavidus necator; Delftia acidovorans; Molecular Weight; Oxidoreductases Acting on Sulfur Group Donors; Periplasmic Proteins; Sequence Analysis, Protein; Sequence Homology, Amino Acid; Transcription, Genetic
PubMed: 18174144
DOI: 10.1099/mic.0.2007/011650-0