-
Journal of Global Antimicrobial... Jun 2020The presence of carbapenemase-producing bacterial isolates is found not only in hospital and community settings but also in the environment. Carbapenemase production may...
OBJECTIVES
The presence of carbapenemase-producing bacterial isolates is found not only in hospital and community settings but also in the environment. Carbapenemase production may be related to acquired, usually plasmid-borne, β-lactamase genes or to chromosomal genes intrinsic to various species. The aim of this study was to evaluate the occurrence of such carbapenemase-producing bacterial isolates among environmental samples from Nigeria.
METHODS
A total of 122 environmental samples were plated on carbapenem-containing media. A total of 259 isolates were recovered, among which 124 were carbapenemase-producers according to the results of the Rapidec® Carba NP test.
RESULTS
The majority of isolates (n=112) recovered corresponded to natural producers of carbapenemases, i.e. Stenotrophomonas maltophilia (n=108), Burkholderia cepacia (n=1), Shewanella sp. (n=1), Sphingobacterium sp. (n=1) and Chryseobacterium gleum (n=1). Ten isolates (mainly Enterobacteriaceae and Acinetobacter baumannii) produced an acquired carbapenemase, most commonly of the NDM type. In addition, two Pseudomonas otitidis isolates were identified as producing the Ambler class B carbapenemase POM-1, further confirming that this carbapenemase is naturally produced in this environmental species. Finally, several isolates co-producing 16S rRNA methylases (ArmA, RmtC) and/or extended-spectrum β-lactamases (CTX-M-9, CTX-M-15) were also identified.
CONCLUSION
This study revealed the presence and diversity of clinically-relevant antimicrobial-resistant bacteria in the environment in Nigeria.
Topics: Bacterial Proteins; Chryseobacterium; Nigeria; Pseudomonas; RNA, Ribosomal, 16S; beta-Lactamases
PubMed: 31639547
DOI: 10.1016/j.jgar.2019.10.014 -
Pathogens (Basel, Switzerland) Feb 2021causes deadly primary amoebic meningoencephalitis (PAM) in humans. Humans obtain the infection by inhaling water or dust contaminated with amebae into the nostrils,...
causes deadly primary amoebic meningoencephalitis (PAM) in humans. Humans obtain the infection by inhaling water or dust contaminated with amebae into the nostrils, wherefrom the pathogen migrates via the olfactory nerve to cause brain inflammation and necrosis. Current PAM treatment is ineffective and toxic. Seeking new effective and less toxic drugs for the environmental control of the amoeba population to reduce human exposure is logical for the management of infection. On the basis of the concept of competitive exclusion, where environmental microorganisms compete for resources by secreting factors detrimental to other organisms, we tested cell-free culture supernatants (CFSs) of three bacteria isolated from a fresh water canal, i.e., , , and , were tested against . The CFSs inhibited growth and caused morphological changes in . At low dose, trophozoites exposed to pyocyanin were seen to shrink and become rounded, while at high dose, the trophozoites were fragmented. While the precise molecular mechanisms of pyocyanin and products of and that also exert anti- activity await clarification. Our findings suggest that pyocyanin may have a role in the control of amphizoic in the environment.
PubMed: 33535404
DOI: 10.3390/pathogens10020142 -
International Health Sep 2020The present study was carried out to investigate the tap water quality of public toilets in Amritsar, Punjab, India.
BACKGROUND
The present study was carried out to investigate the tap water quality of public toilets in Amritsar, Punjab, India.
METHODS
Water samples from the taps of the public toilets were collected in sterile containers and physicochemical and bacteriological analysis was performed using standard methods. Also, genotypic and phenotypic characterization of the bacterial isolates was performed using different biochemical tests and 16S ribosomal RNA analysis. An antibiotic susceptibility test was performed using antibiotics based on their mode of action. A biofilm assay was performed to assess the adhesion potential of the isolates.
RESULTS
A total of 25 bacterial isolates were identified from the water samples, including Acinetobacter junii, Acinetobacter pittii, Acinetobacter haemolyticus, Bacillus pumilus, Bacillus megaterium, Bacillus marisflavi, Bacillus flexus, Bacillus oceanisediminis, Pseudomonas otitidis, Pseudomonas sp. RR013, Pseudomonas sp. RR021, Pseudomonas sp. RR022, Escherichia coli and Enterobacter cloacae. The results of the antimicrobial susceptibility test revealed that the antibiotics cefodroxil, aztreonam, nitrofurantoin, cefepime, ceftazidime and amoxyclav were found to be mostly ineffective against various isolates. The biofilm assay revealed the weak, moderate and strong biofilm producers among them.
CONCLUSIONS
The tap water in the public toilets was microbially contaminated and needs to be monitored carefully. The antibiotic susceptibility profile showed that of 25 bacterial isolates, 5 were multidrug resistant. Bacterial isolates exhibited strong to weak adhesion potential in the biofilm assay.
Topics: Acinetobacter; Anti-Bacterial Agents; Bacillus; Bacterial Infections; Bathroom Equipment; Biofilms; Genotype; Humans; India; Microbial Sensitivity Tests; Phenotype; Pseudomonas; Water; Water Microbiology
PubMed: 31693132
DOI: 10.1093/inthealth/ihz074 -
International Journal of Environmental... Jan 2021Recently, the application of endophytes in the alleviation of different types of stresses has received considerable attention, but their role in drought stress...
Recently, the application of endophytes in the alleviation of different types of stresses has received considerable attention, but their role in drought stress alleviation and growth promotion in soybean is not well-stated. In this study, twenty bacterial endophytes were isolated from soybean root tissues and screened for plant growth-promoting (PGP) traits, biocontrol potential, and drought stress alleviation. Out of them, 80% showed PGP traits, and 20% showed antagonistic activity against (ITCC 2389), (ITCC 1800), and (ITCC 3467), and only three of them showed drought tolerance up to 15% (-0.3 MPa). Results indicated that drought-tolerant PGP endophytic bacteria enhanced soybean seedling growth under drought stress conditions. Morphological, biochemical, and molecular characterization (16S rRNA) revealed that these three bacterial isolates, AKAD A1-1, AKAD A1-2, and AKAD A1-16, closely resemble (GenBank accession No. MN079048), (MW301101), and sp. (MN079074), respectively. We observed that the soybean seedlings were grown in well-watered and drought-stressed soil showed the adverse effect of drought stress on morphological (stem length, root length, plant fresh and dry weight) as well as on biochemical parameters (a decline of photosynthetic pigments, membrane damage, etc.). However, soybean seedlings inoculated with these endophytes have improved the biomass significantly ( ≤ 0.05) under normal as well as in drought stress conditions over control treatments by influencing several biochemical changes. Among these three endophytes, AKAD A1-16 performed better than AKAD A1-2 and AKAD A1-1, which was further validated by the ability to produce the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase in the following order: AKAD A1-16 > AKAD A1-2 > AKAD A1-1. Scanning electron microscopy images also showed a bacterial presence inside the roots of soybean seedlings. These findings supported the application of bacterial root endophytes as a potential tool to mitigate the effect of drought as well as of fungal diseases on the early seedling growth of soybean.
Topics: Alternaria; Ascomycota; Bacteria; Droughts; Endophytes; Fusarium; Plant Roots; Pseudomonas; RNA, Ribosomal, 16S; Glycine max
PubMed: 33494513
DOI: 10.3390/ijerph18030931 -
Ecotoxicology and Environmental Safety Jan 2023Nafion by-product 2 (Nafion BP2), an emerging fluorinated sulfonic acid commonly used in polymer electrolyte membrane technologies, has been detected in various...
Nafion by-product 2 (Nafion BP2), an emerging fluorinated sulfonic acid commonly used in polymer electrolyte membrane technologies, has been detected in various environmental and human matrices. To date, however, few studies have explored its toxicity. In this study, zebrafish embryos were exposed to Nafion BP2 at concentrations of 20, 40, 60, 80, 100, 120, 140, and 160 mg/L from fertilization to 120 post-fertilization (hpf), and multiple developmental parameters (survival rate, hatching rate, and malformation rate) were then determined. Results showed that Nafion BP2 exposure led to a significant decrease in survival and hatching rates and an increase in malformations. The half maximal effective concentration (EC) of Nafion BP2 for malformation at 120 hpf was 55 mg/L, which is higher than the globally important contaminant perfluorooctane sulfonate (PFOS, 6 mg/L). Furthermore, exposure to Nafion BP2 resulted in additional types of malformations compared to PFOS exposure. Pathologically, Nafion BP2 caused abnormal early foregut development, with exfoliation of intestinal mucosa, damage to lamina propria, and aberrant proliferation of lamina propria cells. Nitric oxide content also decreased markedly. In addition, embryos showed an inflammatory response following Nafion BP2 exposure, with significantly increased levels of pro-inflammatory factors C4 and IL-6. Acidic mucin in the hindgut increased more than two-fold. 16 S rRNA sequencing revealed a marked increase in the pathogen Pseudomonas otitidis. Furthermore, pathways involved in intestinal protein digestion and absorption, inflammatory response, and immune response were significantly altered. Our findings suggest that the intestine is a crucial toxicity target of Nafion BP2 in zebrafish, thus highlighting the need to evaluate its health risks.
Topics: Animals; Humans; Embryo, Nonmammalian; Fluorocarbon Polymers; Homeostasis; Intestines; Water Pollutants, Chemical; Zebrafish
PubMed: 36508837
DOI: 10.1016/j.ecoenv.2022.114368 -
Biologia 2022Aquaculture is a highly productive and fast-growing agricultural sector. The occurrence of epidemic or sporadic disease outbreak is a major limiting factor in this...
Aquaculture is a highly productive and fast-growing agricultural sector. The occurrence of epidemic or sporadic disease outbreak is a major limiting factor in this sector, thus better alternatives are the need of the hour. Use of indigenous probiotics is a promising strategy to control infectious diseases. Thus, the present study was aimed to screen and characterize potent indigenous probiotics from marine fish, towards enhancing sustainable aquaculture production. Totally 347 bacterial isolates were obtained from gastrointestinal tract, out of these, four isolates (KAF121, 124, 135, 136) were confirmed as potent probiotics in terms of biosafety, highly resistant to acidic pH, gastric juice, bile salt, high hydrophobicity to solvents, auto and co-aggregation potential. These four isolates also exhibited virtuous antioxidant activity. Further the isolates, KAF124 and 135 proved their efficiency in growth and survival of fish after challenged againt . The isolates were identified based on their 16S rRNA gene sequence and the data were submitted to Genbank as KAF121 (MH393516) KAF124 (MH393226) KAF135 (MH393230) and KAF136 (MH393230). The results conclude that two isolates, KAF124 and KAF135 are highly safe and potent probiotics which are first time isolated from the marine fish The two strains could be used as better alternatives to antibiotics and other chemical-based drugs to prevent/control infectious diseases in aquaculture.
PubMed: 35034969
DOI: 10.1007/s11756-021-00957-w -
Microorganisms Jun 2021The rhizobacterium AVO110 exhibits antagonism toward the phytopathogenic fungus . This strain efficiently colonizes hyphae and is able to feed on their exudates. Here,...
The rhizobacterium AVO110 exhibits antagonism toward the phytopathogenic fungus . This strain efficiently colonizes hyphae and is able to feed on their exudates. Here, we report the complete genome sequence of AVO110. The phylogeny of all available genomes separates environmental isolates, including AVO110, from those obtained from infected human blood and oyster tissues, which cluster together with . Core and pan-genome analyses showed that strains encode highly heterogenic gene pools, with the AVO110 genome encoding the largest and most exclusive variable region (~1.6 Mb, 1795 genes). The AVO110 singletons include a wide repertoire of genes related to biofilm formation, several of which are transcriptionally modulated by exudates. One of these genes () encodes a GGDEF/EAL domain protein specific to spp. strains isolated primarily from the rhizosphere of diverse plants, but also from soil and water samples. We also show that CmpA has a role in biofilm formation and that the integrity of its EAL domain is involved in this function. This study contributes to a better understanding of the niche-specific adaptations and lifestyles of , including the mycophagous behavior of strain AVO110.
PubMed: 34202389
DOI: 10.3390/microorganisms9071388 -
Microbiology Resource Announcements Mar 2024Here, we report the draft genome sequences of strains zfem001-005, five isolates from the intestinal microbiota of healthy larval zebrafish at a developmental age of 7...
Here, we report the draft genome sequences of strains zfem001-005, five isolates from the intestinal microbiota of healthy larval zebrafish at a developmental age of 7 days post fertilization. The isolates have been identified as , , , , and , respectively.
PubMed: 38376340
DOI: 10.1128/mra.00934-23 -
Diagnostic Microbiology and Infectious... May 2007Laboratory detection of Pseudomonas spp., particularly Pseudomonas aeruginosa, is an important assay in the nosocomial control. The study was designed firstly to...
Laboratory detection of Pseudomonas spp., particularly Pseudomonas aeruginosa, is an important assay in the nosocomial control. The study was designed firstly to establish a new assay-applied LightCycler polymerase chain reaction (PCR) technology with melting curve analysis (MCA). A total of 224 Gram-negative isolates were used to verify the assay system. The PCR with MCA method using the P. aeruginosa-specific gyrase B gene primers was rapid and accurate; the total run is approximately 3 h, and the sensitivity and specificity relative to the Vitek (bioMerieux, Hazelwood, MO) results were 98.1% and 100%, respectively. Vitek identification system was not able to identify the isolates from the new Pseudomonas otitidis spp. opposite to the real-time PCR. This assay was validated to be accurate with an overall sensitivity and specificity of 98.7% and 98.9%, respectively. Conclusively, this rapid and accurate PCR assay with MCA will help to manage and control infections with P. aeruginosa.
Topics: Bacterial Typing Techniques; Base Sequence; DNA Gyrase; DNA Primers; DNA, Bacterial; Humans; Molecular Sequence Data; Polymerase Chain Reaction; Pseudomonas Infections; Pseudomonas aeruginosa; Sensitivity and Specificity; Time Factors; Transition Temperature
PubMed: 17368797
DOI: 10.1016/j.diagmicrobio.2006.11.007 -
Microbiological Research Nov 2020In this study, we have attempted to develop a plant growth promoting rhizobacteria (PGPR) consortia against early-stage diseases in Arachis hypogaea (Groundnut crop)...
In this study, we have attempted to develop a plant growth promoting rhizobacteria (PGPR) consortia against early-stage diseases in Arachis hypogaea (Groundnut crop) plantation of Andhra Pradesh, India. The dominant PGPRs were selected by considering the various plant growth and protection qualities, followed by characterisation and grouping based on compatibility to form a consortium of PGPRs [Group-1 includes EX-1 (Acinetobacter baumannii stain HAMBI 1846); EX-3 (Pseudomonas aeruginosa strain A1K319); EX-5 (Bacillus subterraneus strain CF1.9); KNL-1 (Bacillus subtilis strain JMP-B); CTR-4 (Enterobacter cloacae strain VITKJ1); ANT-4 (Bacillus subtilis strain SBMP4) and Group-2 includes EX-4 (Pseudomonas otitidis strain SLC8); KDP-4 (Pseudomonas aeruginosa strain Kasamber 11); NLR-4 (Bacillus species ADMK68); ANT-6 (Bacillus subtilis subsp. inaquosorum strain KCTC 13429)]. In addition to resistance to early stage pathogens, in both in vitro and pot experiments the PGPR consortium showed significantly higher germination rate and root induction (Aspergillus niger; A. flavus; Fusarium oxysporum) when compared to control and fertilizer treated groups. In addition, Group 2 was more successful in stimulating and protecting plant growth among the two groups of PGPRs developed. The PGPR consortia developed showed multiple plant growth characteristics, including phosphate solubilization, production of HCN and Indole acetic acid along with broad antagonism against the tested phytopathogens.
Topics: Acinetobacter baumannii; Arachis; Aspergillus; Aspergillus niger; Bacillus; Bacillus subtilis; Enterobacter cloacae; Fertilizers; Fusarium; India; Indoleacetic Acids; Pest Control; Plant Development; Plant Diseases; Pseudomonas; Pseudomonas aeruginosa; RNA, Ribosomal, 16S; Seeds; Soil Microbiology
PubMed: 32739583
DOI: 10.1016/j.micres.2020.126562