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BMC Microbiology Apr 2021Gram-negative bacteria (GNB) including Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae represent the most relevant reservoir of resistance genes such...
BACKGROUND
Gram-negative bacteria (GNB) including Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae represent the most relevant reservoir of resistance genes such as metallo-β-lactamase (MBL) and AmpC genes that give them the undue advantage to resist antimicrobial onslaught. This study aimed to investigate the occurrence of MBL (bla, bla, bla, bla) and AmpC (bla, bla, bla, bla) resistance genes in aforementioned GNB collected from abattoir and poultry sources in Nigeria.
RESULTS
In total, 370 isolates were collected from abattoir tables (n = 130), anal region of cows (n = 120), and the cloacae of poultry birds (n = 120). The test isolates showed high rate of resistance to cephalosporins and carbapenems. The MBLs were phenotypically detected in 22 E. coli, 22 P. aeruginosa, and 18 K. pneumoniae isolates using combined disc test (CDT). However, only 11 E. coli, 24 P. aeruginosa, and 18 Klebsiella pneumoniae isolates were phenotypically confirmed to be AmpC producers using cefoxitin-cloxacillin double disk synergy test (CC-DDST). MBL encoding genes (particularly the bla genes and bla genes) were detected by polymerase chain reaction (PCR) in 12 (54.6%) E. coli, 15 (83.3%) K. pneumoniae, and 16 (72.7%) P. aeruginosa isolates. AmpC genes (particularly the bla genes and bla genes) were found in a total of 5 (29.4%) E. coli isolates, 5 (27.8%) isolates of K. pneumoniae, and 10 (41.7%) isolates of P. aeruginosa.
CONCLUSIONS
Our study showed the circulation of MBL and AmpC genes in GNB from abattoir and poultry origin in Nigeria. Adoption of regular control policies is necessary to reduce the spread of these species as soon as possible, especially in poultry and slaughterhouses.
Topics: Abattoirs; Animals; Bacterial Proteins; Enterobacteriaceae; Escherichia coli; Klebsiella pneumoniae; Nigeria; Poultry; Pseudomonas aeruginosa; beta-Lactamases
PubMed: 33882823
DOI: 10.1186/s12866-021-02179-1 -
The Nigerian Postgraduate Medical... 2022Carbapenemase-producing Enterobacteriaceae (CPE) have become one of the greatest public health challenges globally. In the past decade, antimicrobial resistance (AMR)... (Review)
Review
Carbapenemase-producing Enterobacteriaceae (CPE) have become one of the greatest public health challenges globally. In the past decade, antimicrobial resistance (AMR) was viewed as a clinical problem in many parts of the world; hence, the role and magnitude of the contribution of the environment were not well appreciated. This review article was done with online published articles extracted from different databases using search terms related to the work. Evidence has shown that there exists the presence of carbapenemase genes in the environment, consequently fuelling the dissemination with alarming consequences. CPE when acquired causes life-threatening infections in humans. The health and economic impact of these infections are numerous, including treatment failure due to limited therapeutic options which hamper the containment of infectious diseases, further contaminating the environment and worsening the public health challenge. It is a well-known fact that the rate of emergence of resistant genes has outpaced the production of new antimicrobial agents, so it is pertinent to institute effective environmental measures to combat the spread of AMR organisms before it will completely gain a foothold and take us back to 'the pre-antibiotic era'. Environmental sources and reservoirs of resistant genes should therefore be amongst the primary targets for the control and prevention of the spread of resistant genes in the environment. This calls for the effective implementation of the 'one health' strategy with stakeholders committed to the design and enforcement of environmental mitigation policies and guidelines.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Carbapenem-Resistant Enterobacteriaceae; Enterobacteriaceae; Enterobacteriaceae Infections; Humans; Nigeria
PubMed: 35900453
DOI: 10.4103/npmj.npmj_95_22 -
Emerging Microbes & Infections Dec 2024Despite carbapenems not being used in animals, carbapenem-resistant Enterobacterales (CRE), particularly New Delhi metallo-β-lactamase-producing CRE (NDM-CRE), are...
Despite carbapenems not being used in animals, carbapenem-resistant Enterobacterales (CRE), particularly New Delhi metallo-β-lactamase-producing CRE (NDM-CRE), are prevalent in livestock. Concurrently, the incidence of human infections caused by NDM-CRE is rising, particularly in children. Although a positive association between livestock production and human NDM-CRE infections at the national level was identified, the evidence of direct transmission of NDM originating from livestock to humans remains largely unknown. Here, we conducted a cross-sectional study in Chengdu, Sichuan Province, to examine the prevalence of NDM-CRE in chickens and pigs along the breeding-slaughtering-retail chains, in pork in cafeterias of schools, and in colonizations and infections from children's hospital and examined the correlation of NDM-CRE among animals, foods and humans. Overall, the increases gradually along the chicken and pig breeding (4.70%/2.0%) -slaughtering (7.60%/22.40%) -retail (65.56%/34.26%) chains. The slaughterhouse has become a hotspot for cross-contamination and amplifier of . Notably, 63.11% of pork from the school cafeteria was positive for . The prevalence of in intestinal and infection samples from children's hospitals was 21.68% and 19.80%, respectively. whole genome sequencing (WGS) analysis revealed the sporadic, not large-scale, clonal spread of NDM-CRE along the chicken and pig breeding-slaughtering-retail chain, with further spreading via IncX3- plasmid within each stage of whole chains. Clonal transmission of NDM-CRE is predominant in children's hospitals. The IncX3- plasmid was highly prevalent among animals and humans and accounted for 57.7% of and 91.3% of . Attention should be directed towards the IncX3 plasmid to control the transmission of between animals and humans.
Topics: Child; Humans; Animals; Swine; Enterobacteriaceae; Cross-Sectional Studies; Anti-Bacterial Agents; Microbial Sensitivity Tests; Chickens; Escherichia coli; beta-Lactamases; Enterobacteriaceae Infections; Klebsiella pneumoniae; Plasmids
PubMed: 38629492
DOI: 10.1080/22221751.2024.2337678 -
Toxins Jan 2022Cytolysin A (ClyA) is a pore-forming toxin that is produced by some bacteria from the family. This review provides an overview of the current state of knowledge... (Review)
Review
Cytolysin A (ClyA) is a pore-forming toxin that is produced by some bacteria from the family. This review provides an overview of the current state of knowledge regarding ClyA, including the prevalence of the encoding gene and its transcriptional regulation, the secretion pathway used by the protein, and the mechanism of protein assembly, and highlights potential applications of ClyA in biotechnology. ClyA expression is regulated at the transcriptional level, primarily in response to environmental stressors, and ClyA can exist stably both as a soluble monomer and as an oligomeric membrane complex. At high concentrations, ClyA induces cytolysis, whereas at low concentrations ClyA can affect intracellular signaling. ClyA is secreted in outer membrane vesicles (OMVs), which has important implications for biotechnology applications. For example, the native pore-forming ability of ClyA suggests that it could be used as a component of nanopore-based technologies, such as sequencing platforms. ClyA has also been exploited in vaccine development owing to its ability to present antigens on the OMV surface and provoke a robust immune response. In addition, ClyA alone or OMVs carrying ClyA fusion proteins have been investigated for their potential use as anti-tumor agents.
Topics: Antineoplastic Agents; Bacterial Vaccines; Cytotoxins; Enterobacteriaceae; Nanopores
PubMed: 35202106
DOI: 10.3390/toxins14020078 -
Applied and Environmental Microbiology Apr 2021We investigated the prevalence and transmission of NDM-producing in fecal samples of geese and environmental samples from a goose farm in southern China. The samples...
We investigated the prevalence and transmission of NDM-producing in fecal samples of geese and environmental samples from a goose farm in southern China. The samples were cultivated on MacConkey agar plates supplemented with meropenem. Individual colonies were examined for , and -positive bacteria were characterized based on whole-genome sequencing (WGS) data from the Illumina and Oxford Nanopore Technologies (ONT) platforms. Of 117 samples analyzed, the carriage rates for New Delhi metallo-β-lactamase (NDM)-positive were 47.1, 18, and 50% in geese, inanimate environments (sewage, soil, fodder, and dust), and mouse samples, respectively. Two variants ( and , in 4 and 40 isolates, respectively) were found among 44 -positive ; these variants belonged to eight species, and was the most prevalent (50%). WGS analysis revealed that coexisted with diverse antibiotic resistance genes (ARGs). Population structure analysis showed that most and sp. isolates were highly heterogeneous, while most sp. and isolates possessed extremely high genetic similarities. In addition, -positive ST4358/ST48 isolates were found to be clonally spread between geese and the environment and were highly genetically similar to those reported from ducks, farm environments, and humans in China. Plasmid analysis indicated that IncX3 pHNYX644-1-like ( = 40) and untypeable pM2-1-like plasmids ( = 4) mediated spread. pM2-1-like plasmids possessed diverse ARGs, including , the arsenical and mercury resistance operons, and the maltose operon. Our findings revealed that the goose farm is a reservoir for NDM-positive The contamination of wild mice and the novel pM2-1-like plasmid described here likely adds to the risk for dissemination of and associated resistance genes. Carbapenem-resistant bacteria, in particular NDM-producing , have become a great threat to global public. These bacteria have been found not only in hospital and community environments but also among food animal production chains, which are recognized as reservoirs for NDM-producing However, the dissemination of NDM-producing bacteria in waterfowl farms has been less well explored. Our study demonstrates that the horizontal spread of -carrying plasmids and the partial clonal spread of -positive contribute to the widespread contamination of in the goose farm ecosystem, including mice. Furthermore, we found a novel and transferable -carrying multidrug resistance (MDR) plasmid that possessed multiple environmental adaptation-related genes. The outcomes of this study contribute to a better understanding of the prevalence and transmission of -carrying among diverse niches in the farm ecosystem.
Topics: Animals; Anti-Bacterial Agents; China; Enterobacteriaceae; Enterobacteriaceae Infections; Farms; Feces; Fomites; Geese; Mice; Microbial Sensitivity Tests; Poultry Diseases; beta-Lactamases
PubMed: 33674440
DOI: 10.1128/AEM.00087-21 -
Microbiology (Reading, England) Apr 2022Microcins are an understudied and poorly characterized class of antimicrobial peptides. Despite the existence of only 15 examples, all identified from the , microcins...
Microcins are an understudied and poorly characterized class of antimicrobial peptides. Despite the existence of only 15 examples, all identified from the , microcins display diversity in sequence, structure, target cell uptake, cytotoxic mechanism of action and target specificity. Collectively, these features describe some of the unique means nature has contrived for molecules to cross the 'impermeable' barrier of the Gram-negative bacterial outer membrane and inflict cytotoxic effects. Microcins appear to be widely dispersed among different species and in different environments, where they function in regulating microbial communities in diverse ways, including through competition. Growing evidence suggests that microcins may be adapted for therapeutic uses such as antimicrobial drugs, microbiome modulators or facilitators of peptide uptake into cells. Advancing our biological, ecological and biochemical understanding of the roles of microcins in bacterial interactions, and learning how to regulate and modify microcin activity, is essential to enable such therapeutic applications.
Topics: Amino Acid Sequence; Anti-Bacterial Agents; Bacteria; Bacteriocins; Enterobacteriaceae
PubMed: 35438625
DOI: 10.1099/mic.0.001175 -
Antimicrobial Resistance and Infection... Oct 2020The environmental role of carbapenemase-producing Enterobacteriaceae (CPE) acquisition and infection in human disease has been described but not thoroughly investigated....
BACKGROUND
The environmental role of carbapenemase-producing Enterobacteriaceae (CPE) acquisition and infection in human disease has been described but not thoroughly investigated. We aimed to assess the occurrence of CPE in nearshore aquatic bodies.
METHODS
Enterobacteriaceae were cultured from coastal and estuary water near Netanya, Israel in June and July of 2018. Bacteria were identified by VITEK2® and their antimicrobial susceptibility was tested according to the CLSI guidelines. Enterobacteriaceae genomes were sequenced to elucidate their resistome and carbapenemase types.
RESULTS
Among other clinically relevant bacteria, four CPE (three Enterobacter spp and one Escherichia coli isolate) were isolated from two river estuaries (Poleg and Alexander Rivers) and coastal water at a popular recreational beach (Beit Yanai). Molecular analysis and genome sequencing revealed the persistent presence of rare beta-lactamase resistance genes, including bla and a previously unknown bla allele, which were not found among the local epidemiological strains. Genome comparisons revealed the high identity of riverine and marine CPE that were cultivated one month apart.
CONCLUSIONS
We show that CPE contamination was widespread in nearshore marine and riverine habitats. The high genome-level similarity of riverine and marine CPEs, isolated one month apart, hints at the common source of infection. We discuss the clinical implications of these findings and stress the urgent need to assess the role of the aquatic environment in CPE epidemiology.
Topics: Carbapenem-Resistant Enterobacteriaceae; Drug Resistance, Multiple, Bacterial; Rivers; Seawater
PubMed: 33126924
DOI: 10.1186/s13756-020-00826-2 -
Microbiology Spectrum Jun 2022The advent of multidrug-resistant bacteria has hampered the development of new antibiotics, exacerbating their morbidity and mortality. In this context, the...
The advent of multidrug-resistant bacteria has hampered the development of new antibiotics, exacerbating their morbidity and mortality. In this context, the gastrointestinal tract reveals a valuable source of novel antimicrobials. Microcins are bacteriocins produced by members of the family which are endowed with a wide diversity of structures and mechanisms of action, and exert potent antibacterial activity against closely related bacteria. In this study, we investigated the antibacterial activities of four microcins against 54 isolates from three species (Escherichia coli, Klebsiella pneumoniae, and Salmonella enterica). The selected microcins, microcin C (McC, nucleotide peptide), microcin J25 (MccJ25, lasso peptide), microcin B17 (MccB17, linear azol(in)e-containing peptide), and microcin E492 (MccE492, siderophore peptide) carry different post-translational modifications and have distinct mechanisms of action. MICs and minimal bactericidal concentrations (MBC) of the microcins were measured and the efficacy of combinations of the microcins together or with antibiotics was assessed to identify potential synergies. Every isolate showed sensitivity to at least one microcin with MIC values ranging between 0.02 μM and 42.5 μM. Among the microcins tested, McC exhibited the broadest spectrum of inhibition with 46 strains inhibited, closely followed by MccE492 with 38 strains inhibited, while MccJ25 showed the highest activity. In general, microcin activity was observed to be independent of antibiotic resistance profile and strain genus. Of the 42 tested combinations, 20 provided enhanced activity (18 out of 20 being microcin-antibiotic combinations), with two being synergetic. With their wide range of structures and mechanisms of action, microcins are shown to exert antibacterial activities against resistant to antibiotics together with synergies with antibiotics and in particular colistin.
Topics: Amino Acid Sequence; Anti-Bacterial Agents; Bacteriocins; Drug Resistance, Multiple, Bacterial; Enterobacteriaceae; Escherichia coli; Peptides
PubMed: 35543514
DOI: 10.1128/spectrum.02752-21 -
Annals of the Academy of Medicine,... Aug 2021
Topics: Anti-Bacterial Agents; Bacteremia; Enterobacteriaceae; Hospitals; Humans; Singapore
PubMed: 34472560
DOI: 10.47102/annals-acadmedsg.202195 -
PloS One 2020Microbiome research has experienced a surge of interest in recent years due to the advances and reduced cost of next-generation sequencing technology. The production of...
Microbiome research has experienced a surge of interest in recent years due to the advances and reduced cost of next-generation sequencing technology. The production of high quality and comparable data is dependent on proper sample collection and storage and should be standardized as far as possible. However, this becomes challenging when samples are collected in the field, especially in resource-limited settings. We investigated the impact of different stool storage methods common to the TB-CHAMP clinical trial on the microbial communities in stool. Ten stool samples were subjected to DNA extraction after 48-hour storage at -80°C, room temperature and in a cooler-box, as well as immediate DNA extraction. Three stool DNA extraction kits were evaluated based on DNA yield and quality. Quantitative PCR was performed to determine the relative abundance of the two major gut phyla Bacteroidetes and Firmicutes, and other representative microbial groups. The bacterial populations in the frozen group closely resembled the immediate extraction group, supporting previous findings that storage at -80°C is equivalent to the gold standard of immediate DNA extraction. More variation was seen in the room temperature and cooler-box groups, which may be due to the growth temperature preferences of certain bacterial populations. However, for most bacterial populations, no significant differences were found between the storage groups. As seen in other microbiome studies, the variation between participant samples was greater than that related to differences in storage. We determined that the risk of introducing bias to microbial community profiling through differences in storage will likely be minimal in our setting.
Topics: Child, Preschool; DNA, Bacterial; Enterobacteriaceae; Feces; Fungi; Humans; Microbiota; RNA, Ribosomal, 16S; Specimen Handling
PubMed: 31935223
DOI: 10.1371/journal.pone.0227486