Copper and Zinc Tolerance in Bacteria Isolated from Fresh Produce

2017 ◽  
Vol 80 (6) ◽  
pp. 969-975 ◽  
Author(s):  
Ismael Cidre ◽  
Rubén Pérez Pulido ◽  
Maria José Grande Burgos ◽  
Antonio Gálvez ◽  
Rosario Lucas
Keyword(s):  
Resistance Genes ◽  
Fresh Produce ◽  
Metal Resistance ◽  
Copper Tolerance ◽  
Zinc Tolerance ◽  
Green Pepper ◽  
Copper And Zinc ◽  
Rdna Sequencing ◽  
Zn Tolerance ◽  
Cu And Zn

ABSTRACT The continued agricultural exposure of bacteria to metals such as copper and zinc may result in an increased copper tolerance through the food chain. The aim of this study was to determine the Cu and Zn tolerance of bacteria from fresh produce (cucumber, zucchini, green pepper, tomato, lettuce, vegetable salad, broccoli, cabbage, carrot, green onion, onion, and mango). Isolates (506 aerobic mesophiles) from 12 different food produce products were tested for growth in a range of Cu and Zn concentrations. Selected isolates were identified using 16S rDNA sequencing, and the presence of metal resistance genes was studied using PCR amplification. More than 50% of the isolates had MICs for copper sulfate greater than 16 mM, and more than 40% had MICs greater than 4 mM for zinc chloride. Isolates with high levels of tolerance to Cu and Zn were detected in all the produce products investigated. A selection of 51 isolates with high MICs for both Cu and Zn were identified as belonging to the genera Pseudomonas (28), Enterobacter (7), Serratia (4), Leclercia (1), Bacillus (10), and Paenibacillus (1). A study of the genetic determinants of resistance in the selected gram-negative isolates revealed a high incidence of genes from the pco multicopper oxidase cluster, from the sil cluster involved in Cu and silver resistance, and from the chromate resistance gene chrB. A high percentage carried both pco and sil. The results suggest that Cu and Zn tolerance, as well as metal resistance genes, is widespread in bacteria from fresh produce.

scholarly journals Metagenomics of Antimicrobial and Heavy Metal Resistance in the Cecal Microbiome of Fattening Pigs Raised without Antibiotics

2021 ◽  
Vol 87 (8) ◽  
Author(s):  
Paiboon Tunsagool ◽  
Wuttichai Mhuantong ◽  
Sithichoke Tangphatsornruang ◽  
Nutthee Am-In ◽  
Rungtip Chuanchuen ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Resistance Genes ◽  
Tetracycline Resistance ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Feed Additives ◽  
Farm Animals ◽  
Content Type ◽  
Fattening Pigs ◽  
Cu And Zn

ABSTRACT This study aimed to assess the cecal microbiome, antimicrobial resistance (AMR), and heavy-metal resistance genes (MRGs) in fattening pigs raised under antibiotic-free (ABF) conditions compared with ordinary industrial pigs (control, C) using whole-genome shotgun sequencing. ABF pigs showed enrichment of Prevotella (33%) and Lactobacillus (13%), whereas Escherichia coli (40%), Fusobacterium, and Bacteroides (each at 4%) were notably observed in the C group. Distinct clusters of cecal microbiota of ABF and C pigs were revealed; however, microbiota of some C pigs (C1) appeared in the same cluster as ABF and were totally separated from the remaining C pigs (C2). For AMR genes, the most abundant genes, tet(Q) (35.7%) and mef(A) (12.7%), were markedly observed in the ABF group, whereas tet(Q) (26.2%) and tet(W) (10.4%) were prominently shown in the C group. tet(Q) was positively correlated with Prevotella in ABF and C1 samples. In the C2 group, the prominent tet(W) was positively correlated with Fusobacterium and Bacteroides. The pigs studied here have never received tetracycline, but pregnant sows received chlortetracycline once every 7 days before parturition. Chromosomal Cu and Zn resistance genes were also shown in both groups regardless of the received Cu and Zn feed additives. A higher abundance of multimetal resistance genes was observed in the C group (44%) than with the ABF group (41%). In conclusion, the microbiome clusters in some C pigs were similar to that in ABF pigs. High-abundance tetracycline resistance genes interrelated to major bacteria were observed in both ABF and C pigs. MRGs were also observed. IMPORTANCE AMR is an increasing problem in farm animals, and raising farm animals without antibiotics is one method that could solve this problem. Our study showed that only some tetracycline and macrolide resistance genes, tet(Q), tet(W), and mef(A), were markedly abundant in ABF and C groups. The tet(Q) and tet(W) genes interrelated to different predominant bacteria in each group, showing the potential role of major bacteria as reservoirs of AMR genes. In addition, chromosomal Cu and Zn resistance genes were also observed in both pig groups, independent of the use of Cu and Zn additives on both farms. The association of MRGs and AMR genotypes and phenotypes, together with the method to resensitize bacteria to antibiotics, should be studied further to unveil the cause of genes conferring high-level resistance and solve these problems.

scholarly journals Comparative Genomic Analysis of 450 Strains of Salmonella enterica Isolated from Diseased Animals

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1025
Author(s):  
Shaohua Zhao ◽  
Cong Li ◽  
Chih-Hao Hsu ◽  
Gregory H. Tyson ◽  
Errol Strain ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Bacterial Infections ◽  
Genomic Analysis ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Comparative Genomic ◽  
Salmonella Infections ◽  
Antimicrobial Resistance Genes ◽  
Salmonella Pathogenicity Islands ◽  
Shed Light

Salmonella is a leading cause of bacterial infections in animals and humans. We sequenced a collection of 450 Salmonella strains from diseased animals to better understand the genetic makeup of their virulence and resistance features. The presence of Salmonella pathogenicity islands (SPIs) varied by serotype. S. Enteritidis carried the most SPIs (n = 15), while S. Mbandaka, S. Cerro, S. Meleagridis, and S. Havana carried the least (n = 10). S. Typhimurium, S. Choleraesuis, S. I 4,5,12:i:-, and S. Enteritidis each contained the spv operon on IncFII or IncFII-IncFIB hybrid plasmids. Two S. IIIa carried a spv operon with spvD deletion on the chromosome. Twelve plasmid types including 24 hybrid plasmids were identified. IncA/C was frequently associated with S. Newport (83%) and S. Agona (100%) from bovine, whereas IncFII (100%), IncFIB (100%), and IncQ1 (94%) were seen in S. Choleraesuis from swine. IncX (100%) was detected in all S. Kentucky from chicken. A total of 60 antimicrobial resistance genes (ARGs), four disinfectant resistances genes (DRGs) and 33 heavy metal resistance genes (HMRGs) were identified. The Salmonella strains from sick animals contained various SPIs, resistance genes and plasmid types based on the serotype and source of the isolates. Such complicated genomic structures shed light on the strain characteristics contributing to the severity of disease and treatment failures in Salmonella infections, including those causing illnesses in animals.

scholarly journals Retromobilization of heavy metal resistance genes in unpolluted and heavy metal polluted soil

1995 ◽  
Vol 18 (3) ◽  
pp. 191-203 ◽  
Author(s):  
Eva M. Top ◽  
Helene Rore ◽  
Jean-Marc Collard ◽  
Veerle Gellens ◽  
Galina Slobodkina ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Resistance Genes ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Polluted Soil

scholarly journals Variation in copper and zinc tolerance and accumulation in 12 willow clones: implications for phytoextraction

2014 ◽  
Vol 15 (9) ◽  
pp. 788-800 ◽  
Author(s):  
Wei-dong Yang ◽  
Yu-yan Wang ◽  
Feng-liang Zhao ◽  
Zhe-li Ding ◽  
Xin-cheng Zhang ◽  
...  
Keyword(s):  
Zinc Tolerance ◽  
Copper And Zinc

Analysis of Native Microflora and Selection of Strains Antagonistic to Human Pathogens on Fresh Produce†

2001 ◽  
Vol 64 (8) ◽  
pp. 1110-1115 ◽  
Author(s):  
CHING-HSING LIAO ◽  
WILLIAM F. FETT
Keyword(s):  
Fresh Produce ◽  
Brain Heart Infusion ◽  
Erwinia Carotovora ◽  
Plate Count ◽  
Human Pathogens ◽  
Green Pepper ◽  
Significant Difference ◽  
Bell Peppers ◽  
Native Microflora ◽  
Baby Carrots

The native microflora of three types of produce (green bell peppers, Romaine lettuce, and prepeeled baby carrots) and two types of sprouting seeds (alfalfa and clover) were investigated. Aerobic plate count (APC) for each produce or seed type as determined on Pseudomonas agar F (PAF) with incubation at 28°C was in the range of 4 to 7 log CFU per g of tissue or seed. There was no significant difference (P ≥ 0.05) in APC when the determinations were made with three agar media including PAF, brain heart infusion agar, and plate count agar. However, the APC as determined from plates that were incubated at 28°C was significantly (P ≤ 0.05) higher than with incubation at 37°C. Fluorescent pseudomonads accounted for 23 to 73% of APC and 6 to 18% of APC recovered from carrots, pepper, and lettuce were pectolytic. Forty-eight strains of pectolytic bacteria were randomly isolated and identified, respectively, as members of the genera of Pseudomonas, Erwinia, Bacillus, Xanthomonas, or Flavobacterium. Lactic acid bacteria and/or yeast were consistently isolated from baby carrots, lettuce, and sprouting seeds (alfalfa or clover) but not from green bell peppers. Approximately 120 strains of indigenous microflora were tested for their ability to inhibit the growth of Salmonella Chester, Listeria monocytogenes, Escherichia coli, or Erwinia carotovora subsp. carotovora on PAF. Six isolates capable of inhibiting the growth of at least one pathogen were isolated and identified, respectively, as Bacillus spp. (three strains), Pseudomonas aeruginosa (one strain), Pseudomonas fluorescens (strain A3), and yeast (strain D1). When green pepper disks were inoculated with strains A3 and D1, the growth of Salmonella Chester and L. monocytogenes on the disks was reduced by 1 and 2 logs, respectively, over a period of 3 days. Application of strains A3 and D1 as potential biopreservatives for enhancing the quality and safety of fresh produce is discussed.

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