scholarly journals Assessing the Bacterial Community Composition of Bivalve Mollusks Collected in Aquaculture Farms and Respective Susceptibility to Antibiotics

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1135
Author(s):  
Vanessa Salgueiro ◽  
Lígia Reis ◽  
Eugénia Ferreira ◽  
Maria João Botelho ◽  
Vera Manageiro ◽  
...  

Aquaculture is a growing sector, providing several products for human consumption, and it is therefore important to guarantee its quality and safety. This study aimed to contribute to the knowledge of bacterial composition of Crassostrea gigas, Mytilus spp. and Ruditapes decussatus, and the antibiotic resistances/resistance genes present in aquaculture environments. Two hundred and twenty-two bacterial strains were recovered from all bivalve mollusks samples belonging to the Aeromonadaceae, Bacillaceae, Comamonadaceae, Enterobacteriaceae, Enterococcaceae, Micrococcaceae, Moraxellaceae, Morganellaceae, Pseudomonadaceae, Shewanellaceae, Staphylococcaceae, Streptococcaceae, Vibrionaceae, and Yersiniaceae families. Decreased susceptibility to oxytetracycline prevails in all bivalve species, aquaculture farms and seasons. Decreased susceptibilities to amoxicillin, amoxicillin/clavulanic acid, cefotaxime, cefoxitin, ceftazidime, chloramphenicol, florfenicol, colistin, ciprofloxacin, flumequine, nalidixic acid and trimethoprim/sulfamethoxazole were also found. This study detected six qnrA genes among Shewanella algae, ten qnrB genes among Citrobacter spp. and Escherichia coli, three oqxAB genes from Raoultella ornithinolytica and blaTEM-1 in eight E. coli strains harboring a qnrB19 gene. Our results suggest that the bacteria and antibiotic resistances/resistance genes present in bivalve mollusks depend on several factors, such as host species and respective life stage, bacterial family, farm’s location and season, and that is important to study each aquaculture farm individually to implement the most suitable measures to prevent outbreaks.

Author(s):  
Andreea Paula COZMA ◽  
Ioana CRIVEI ◽  
Oana Alexandra CIOCAN ◽  
Catalin CARP-CARARE ◽  
Cristina RIMBU ◽  
...  

The animals producing food have become an increasing reservoir of extended spectrum beta-lactamase producing Enterobacteriaceae. The calves and cows are exposed to a greater quantity of antibiotics, but the data concerning the prevalence of ESBL-producing Enterobacteriaceae are not enough, in comparison with other species of animals used for human consumption, such as birds (Hordijk et al., 2013).The aim of this study was to determine the prevalence of ESBL-producing E. coli involved in some episodes of colibacilosis in calves. Faeces samples were collected from 33 calves with the age ranging between 1-2 weeks and that presented clinical signs of colibacilosis. The samples were collected in a sterile medium for the taxonomic isolation and identification of the etiological agent involved, the ESBL screening being conducted subsequently using the ESBL Agar Oxoid Brilliance chromogenic medium. The phenotypic confirmation of the ESBL-producing strains was conducted in accordance with the CLSI (2014) standard through the combined disc method. Following the tests conducted, out of the 33 strains of isolated E. coli, 9 (27, 27%) were phenotypically confirmed as being ESBL strains.The studies that were previously conducted on the dairy farms have pointed out that the young calves rapidly acquire bacterial strains resistant to antibiotics that are often ESBL strains (Hordijk et al., 2013). The prevalence obtained by us, as well as an insufficient quantity of information concerning the antimicrobial resistance on this segment of species of animals used for the human consumption, support conducting a more thorough study, as well as the identification of ESBL resistance genes, but also of the plasmids that encode the transmission of these genes.


2021 ◽  
Author(s):  
Ghassan Tayh ◽  
Salma Mariem Boubaker ◽  
Rym Ben Khedher ◽  
Mounir Jbeli ◽  
Faten Ben Chehida ◽  
...  

Abstract Background: Shiga toxin-producing Escherichia coli (STEC) O157:H7 is associated with intestinal infection in human and considered a main cause of food-borne diseases. It was isolated from animals, human and food. The aim of the study was to assess the incidence of E. coli O157:H7 in fecal samples of healthy cattle collected in slaughterhouses (n=160) and from farms (n=100).Methods: E. coli isolates were detected on MacConkey agar. A total of 236 E. coli isolates were recovered from fecal samples of healthy cattle. We used sorbitol MacConkey to detect non-sorbitol fermenting colonies that were examined for the presence of O157 antigen by latex agglutination, and positive bacteria were screened for the existence of stx1, stx2, eaeA and ehxA by PCR as well as rfbEO157 and fliCH7 genes specific for serotype O157. All isolates were examined for the susceptibility against 21antibiotics discs.Results: Of the 236 E. coli isolates, 4.2% (10/236) were positive for STEC O157:H7. Shiga toxin gene (stx2) was present in 70% of isolates, stx1 and ehxA were confirmed in 60% of the isolates, whereas eae was identified in two isolates. Other virulence factors screened (fimH, sfa/focDE, cdt3, traT, iutA and hly) were present among the 10 isolates. All E. coli O157:H7 isolates were sensitive to amoxicillin/clavulanic acid, cefotaxime, cefepime, aztreonam, colistin and sulfamethoxazole/trimethoprim. All isolates belong to the phylo-group E.Conclusion: This is the first study of the incidence of E. coli O157:H7 in cattle in Tunisia. Our finding proves the existence of STEC O157:H7 in healthy animals producing food for human consumption which could be a source of human contamination.


2017 ◽  
Vol 80 (3) ◽  
pp. 488-496 ◽  
Author(s):  
Maria Aparecida da RessurreiÇão Brandão ◽  
Amanda Teixeira Sampaio Lopes ◽  
Maria Tereza da Silva Neta ◽  
Rhyan Barros Farias de Oliveira ◽  
Rachel Passos Rezende ◽  
...  

ABSTRACTThe microbiological quality of oysters reflects the microbiological quality of their habitats because they are filter feeders. The objective of this study was to assess the bacterial composition of the edible oyster Crassostrea rhizophorae in urban and preserved estuaries. Particularly, we assessed the presence of pathogenic bacteria, investigated antibiotic susceptibility in bacterial isolates, and quantified β-lactam antibiotic resistance genes (blaTEM, blaSHV, and blaKPC) via quantitative PCR of oyster DNA. Our results detected total coliforms, Escherichia coli, and enterobacteria in the oysters from urban estuaries, which is indicative of poor water quality. In addition, our detection of the eaeA and stxA2 virulence genes in 16.7% of E. coli isolates from oysters from this region suggests the presence of multiantibiotic-resistant enteropathogenic and enterohemorrhagic E. coli strains. During periods of low precipitation, increased contamination by E. coli (in winter) and Vibrio parahaemolyticus (in autumn) was observed. In contrast, cultivated oysters inhabiting monitored farms in preserved areas had low levels of bacterial contamination, emphasizing that oyster culture monitoring enhances food quality and makes oysters fit for human consumption. Distinct antibiotic resistance profiles were observed in bacteria isolated from oysters collected from different areas, including resistance to β-lactam antibiotics. The presence of the blaTEM gene in 91.3% of oyster samples indicated that microorganisms in estuarine water conferred the capability to produce β-lactamase. To our knowledge, this is the first study to directly quantify and detect β-lactam antibiotic resistance genes in oysters. We believe our study provides baseline data for bacterial dynamics in estuarine oysters; such knowledge contributes to developing risk assessments to determine the associated hazards and consequences of consuming oysters from aquatic environments containing pathogenic bacteria that may possess antibiotic resistance genes.


Author(s):  
A. Zakou ◽  
I. H. Nkene ◽  
R. H. Abimiku ◽  
I. Yahaya ◽  
B. E. Bassey ◽  
...  

Aims: This study evaluated the presence of extended spectrum β-lactamase (ESBL) and AmpC β-lactamase resistance genes in E. coli from stool of diarrheic children in some hospitals in Lafia metropolis, Nigeria. Methodology: A total of 70 stool samples of children were obtained from Dalhatu Araf Specialist Hospital, Lafia, M & D Hospital, Olivet Medical Centre and Sandaji Medical Centre, Lafia. Escherichia coli were isolated and identified using standard microbiological methods. Antimicrobial susceptibility of the isolates was tested using Clinical and Laboratory Standards Institute (CLSI) method. The phenotypic detection of ESBL and AmpC β-lactamase production in some antibiotic resistant isolates were carried out using disc method. The molecular detections of ESBL and AmpC resistance genes were carried out using Polymerase Chain reaction (PCR) method. Results: Of the 70 samples, the occurrence of E. coli was 100%. The isolates were highly resistant to ampicillin (97.14%), ciprofloxacin (90.00%), sulfamethoxazole/trimethoprim (84.29%), streptomycin (78.57%), amoxicillin/clavulanic acid (70.00%); moderate to gentamicin (38.57%), ceftazidime (37.14%) and cefotaxime (30.00%); and less resistant to cefoxitin (15.71%) and imipenem (8.57%). Twenty-one (30.00%) isolates were jointly resistant to both cefotaxime and ceftazidine. Of this number, 66.67% (14/21) were phenotypically confirmed ESBL producers; and the occurrences of ESBL resistance genes were: 7.14% (SHV), 42.86% (CTX-M) and 50.00% (TEM). Out of 11isolates resistant to cefoxitin, 4(36.36%) were phenotypically confirmed as AmpC β-lactamase producers; and the occurrence of AmpC genes were: 50.00% (CIT), 25.00% (FOX) and 25.00% (MOX). Conclusion: The isolates were least resistant to imipenem and cefoxitin and highly resistant to ampicillin, ciprofloxacin and sulfamethoxazole/trimethoprim. TEM and CTX-M ESBL genes were more frequent than SHV. CIT AmpC gene was more frequent than FOX and MOX.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Yuting Zhai ◽  
Shinyoung Lee ◽  
Lin Teng ◽  
Zhengxin Ma ◽  
Nicole B Hilliard ◽  
...  

Abstract Background NDM-producing Enterobacteriaceae are a major clinical concern worldwide. We characterized NDM-positive pathogens isolated from patients and assessed the dissemination patterns of the blaNDM genes in a hospital setting. Methods Eleven NDM-positive Enterobacteriaceae (three Enterobacter hormaechei, six Klebsiella pneumoniae and two Escherichia coli) were isolated from nine patients over a 1 year period. Antimicrobial susceptibility was assessed by MICs. A combination of short- and long-read WGS was used for genome analysis. Clinical treatment history of patients was linked with genetic features of individual isolates to investigate the dissemination patterns of the blaNDM genes and NDM-positive strains. Results bla NDM in clonal K. pneumoniae were transmitted between two patients. In other instances, an identical IncC plasmid encoding NDM-1 was transmitted between E. coli and K. pneumoniae isolated from the same patient, and an IncX3 plasmid, carrying blaNDM-1 or blaNDM-5, was harboured in non-clonal E. hormaechei. Varying patterns of IS elements were identified as a critical transmission mechanism in association with blaNDM genes. Conclusions Multiple transmission patterns were identified in hospitalized patients, including dissemination of clonal bacterial strains carrying resistance genes and horizontal transfer of resistance genes among divergent bacterial strains. Controlling spread of NDM is complex: while attention to standard infection control practices is critically important, this needs to be matched by aggressive efforts to limit unnecessary antimicrobial use, to minimize the selection for and risk of transfer of ‘high mobility’ resistance genes among Enterobacteriaceae.


Author(s):  
Mohamed Sabri Khelfaoui ◽  
Rayane Zeroug ◽  
Maroua Yousfi ◽  
Bouchra Satha

Background: Urinary tract infections (UTIs) are a serious world-wide health problem whose treatment becomes highly difficult due to the emergence of antibiotic-resistant bacterial strains. Aims: Herein, a retrospective study was conducted with the aim to determine the prevalence, the identification of the bacteria responsible of UTIs, and the antimicrobial resistance profile. Study Design: All Patient samples, including either external samples or samples taken from patients admitted to Public Hospital Establishment “Saad Guermech Saoudi Amar Hmaida” in Skikda-Algeria were used in this study for a period extending from January 2018 – March 2020. Methodology: The identification of bacterial strains and the antibiotic susceptibility testing was carried out using Analytical Profile index galleries (API) system and disk diffusion method. Results: Among the 1203 samples, 206 (17.12%) were positive, and 997 (82.88%) were negative for bacterial growth. Regarding the pathogenic strains, 26 (12.62%), and 180 (87.38%) were found respectively, Gram-positive and Gram-negative strains. Among the 180 Gram negative strains, 104 (57.83%) were reported in female patients, 68 (37.72%) were in male patients, and 8 (4.45%) whose gender was not mentioned. The most representative Gram-negative strains are Escherichia coli (E. coli) (43.33%), Klebsiella pneumoniae (K. pneumoniae) (13.33%), Proteus mirabilis (P. mirabilis) (7.77%), Enterobacter sp (E. sp) (6.66%), since the other strains were less frequent. Moreover, 6 bacterial strains belonging to 3 genera (Escherichia, Klebsiella, and Enterobacter) were ESBLs producers with an overall prevalence of 3.33% of pathogenic strains isolated from urine. ESBLs were produced in 4.00%, 5.88%, and 6.25% of E. coli, K. pneumoniae, and E. cloacae strains respectively. Conclusion: E. coli was found to be the most predominant strain, while most of the Gram- negative strains were highly resistant to Amoxicillin/clavulanic acid, Ampicillin, penicillin and tobramycin.


mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Michelle M. C. Buckner ◽  
M. Laura Ciusa ◽  
Richard W. Meek ◽  
Alice R. Moorey ◽  
Gregory E. McCallum ◽  
...  

ABSTRACT Antimicrobial-resistant (AMR) infections pose a serious risk to human and animal health. A major factor contributing to this global crisis is the sharing of resistance genes between different bacteria via plasmids. The WHO lists Enterobacteriaceae, such as Escherichia coli and Klebsiella pneumoniae, producing extended-spectrum β-lactamases (ESBL) and carbapenemases as “critical” priorities for new drug development. These resistance genes are most often shared via plasmid transfer. However, finding methods to prevent resistance gene sharing has been hampered by the lack of screening systems for medium-/high-throughput approaches. Here, we have used an ESBL-producing plasmid, pCT, and a carbapenemase-producing plasmid, pKpQIL, in two different Gram-negative bacteria, E. coli and K. pneumoniae. Using these critical resistance-pathogen combinations, we developed an assay using fluorescent proteins, flow cytometry, and confocal microscopy to assess plasmid transmission inhibition within bacterial populations in a medium-throughput manner. Three compounds with some reports of antiplasmid properties were tested; chlorpromazine reduced transmission of both plasmids and linoleic acid reduced transmission of pCT. We screened the Prestwick library of over 1,200 FDA-approved drugs/compounds. From this, we found two nucleoside analogue drugs used to treat HIV, abacavir and azidothymidine (AZT), which reduced plasmid transmission (AZT, e.g., at 0.25 μg/ml reduced pCT transmission in E. coli by 83.3% and pKpQIL transmission in K. pneumoniae by 80.8% compared to untreated controls). Plasmid transmission was reduced by concentrations of the drugs which are below peak serum concentrations and are achievable in the gastrointestinal tract. These drugs could be used to decolonize humans, animals, or the environment from AMR plasmids. IMPORTANCE More and more bacterial infections are becoming resistant to antibiotics. This has made treatment of many infections very difficult. One of the reasons this is such a large problem is that bacteria are able to share their genetic material with other bacteria, and these shared genes often include resistance to a variety of antibiotics, including some of our drugs of last resort. We are addressing this problem by using a fluorescence-based system to search for drugs that will stop bacteria from sharing resistance genes. We uncovered a new role for two drugs used to treat HIV and show that they are able to prevent the sharing of two different types of resistance genes in two unique bacterial strains. This work lays the foundation for future work to reduce the prevalence of resistant infections.


Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.


2019 ◽  
pp. 48-54
Author(s):  
Duy Binh Nguyen ◽  
Trung Tien Phan ◽  
Trong Hanh Hoang ◽  
Van Tuan Mai ◽  
Xuan Chuong Tran

Sepsis is a serious bacterial infection. The main treatment is using antibiotics. However, the rate of antibiotic resistance is very high and this resistance is related to the outcome of treatment. Objectives: To evaluate the situation of antibiotic resistance of some isolated bacteria in sepsis patients treated at Hue Central Hospital; to evaluate the relationship of antibiotic resistance to the treatment results in patients with sepsis. Subjects and methods: prospective study of 60 sepsis patients diagnosed according to the criteria of the 3rd International Consensus-Sepsis 3 and its susceptibility patterns from April 2017 to August 2018. Results and Conclusions: The current agents of sepsis are mainly S. suis, Burkhoderiae spp. and E. coli. E. coli is resistant to cephalosporins 3rd, 4th generation and quinolone group is over 75%; resistance to imipenem 11.1%; the ESBL rate is 60%. S. suis resistant to ampicilline 11.1%; no resistance has been recorded to ceftriaxone and vancomycine. Resistance of Burkholderiae spp. to cefepime and amoxicillin/clavulanic acid was 42.9% and 55.6%, resistant to imipenem and meropenem is 20%, resistance to ceftazidime was not recorded. The deaths were mostly dued to E. coli and K. pneumoniae. The mortality for patients infected with antibiotic-resistant bacteria are higher than for sensitive groups. Key words: Sepsis, bacterial infection, antibiotics


2021 ◽  
Vol 11 (9) ◽  
pp. 4315
Author(s):  
Emanuel Vamanu ◽  
Laura Dorina Dinu ◽  
Cristina Mihaela Luntraru ◽  
Alexandru Suciu

Bioactive compounds and phenolic compounds are viable alternatives to antibiotics in recurrent urinary tract infections. This study aimed to use a natural functional product, based on the bioactive compounds’ composition, to inhibit the uropathogenic strains of Escherichia coli. E. coli ATCC 25922 was used to characterize the IVCM (new in vitro catheterization model). As support for reducing bacterial proliferation, the cytotoxicity against a strain of Candida albicans was also determined (over 75% at 1 mg/mL). The results were correlated with the analysis of the distribution of biologically active compounds (trans-ferulic acid-268.44 ± 0.001 mg/100 g extract and an equal quantity of Trans-p-coumaric acid and rosmarinic acid). A pronounced inhibitory effect against the uropathogenic strain E. coli 317 (4 log copy no./mL after 72 h) was determined. The results showed a targeted response to the product for tested bacterial strains. The importance of research resulted from the easy and fast characterization of the functional product with antimicrobial effect against uropathogenic strains of E. coli. This study demonstrated that the proposed in vitro model was a valuable tool for assessing urinary tract infections with E. coli.


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