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ABSTRACT: Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbuco Archipelago, Chile, over 12-month period at a salmon aquaculture site approximately 20 m from a salmon farm and at a control site 8 km distant without observable aquaculture activities. Three antimicrobials extensively used in Chilean salmon aquaculture (oxytetracycline, oxolinic acid, and florfenicol) were studied. Although none of these antimicrobials was detected in sediments from either site, traces of flumequine, a fluoroquinolone antimicrobial also widely used in Chile, were present in sediments from both sites during this period. There were significant increases in bacterial numbers and antimicrobial-resistant fractions to oxytetracycline, oxolinic acid, and florfenicol in sediments from the aquaculture site compared to those from the control site. Interestingly, there were similar numbers of presumably plasmid-mediated resistance genes for oxytetracycline, oxolinic acid and florfenicol in unselected marine bacteria isolated from both aquaculture and control sites. These preliminary findings in one location may suggest that the current use of large amounts of antimicrobials in Chilean aquaculture has the potential to select for antimicrobial-resistant bacteria in marine sediments.
PLoS ONE 01/2012; 7(8):e42724. · 4.09 Impact Factor
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ABSTRACT: Borrelia burgdorferi contains one 16S and two tandem sets of 23S-5S ribosomal (r) RNA genes whose patterns of transcription and regulation are unknown but are likely to be critical for survival and persistence in its hosts.
RT-PCR of B. burgdorferi N40 and B31 revealed three rRNA region transcripts: 16S rRNA-alanine transfer RNA (tRNA Ala); tRNA Ile; and both sets of 23S-5S rRNA. At 34°C, there were no differences in growth rate or in accumulation of total protein, DNA and RNA in B31 cultured in Barbour-Stoenner-Kelly (BSK)-H whether rabbit serum was present or not. At 23°C, B31 grew more slowly in serum-containing BSK-H than at 34°C. DNA per cell was higher in cells in exponential as compared to stationary phase at either temperature; protein per cell was similar at both temperatures in both phases. Similar amounts of rRNA were produced in exponential phase at both temperatures, and rRNA was down-regulated in stationary phase at either temperature. Interestingly, a rel Bbu deletion mutant unable to generate (p)ppGpp did not down-regulate rRNA at transition to stationary phase in serum-containing BSK-H at 34°C, similar to the relaxed phenotype of E. coli relA mutants.
We conclude that rRNA transcription in B. burgdorferi is complex and regulated both by growth phase and by the stringent response but not by temperature-modulated growth rate.
BMC Microbiology 01/2011; 11:17. · 3.04 Impact Factor
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ABSTRACT: Bacterial pathogens face constant challenges from DNA-damaging agents generated by host phagocytes. Although Borrelia burgdorferi appears to have much fewer DNA repair enzymes than pathogens with larger genomes, it does contain homologues of uvrA and uvrB (subunits A and B of excinuclease ABC). As a first step to exploring the physiologic function of uvrA(Bbu) and its possible role in survival in the host in the face of DNA-damaging agents, a partially deleted uvrA mutant was isolated by targeted inactivation. While growth of this mutant was markedly inhibited by UV irradiation, mitomycin C (MMC) and hydrogen peroxide at doses that lacked effect on wild-type B. burgdorferi, its response to pH 6.0-6.8 and reactive nitrogen intermediates was similar to that of the wild-type parental strain. The sensitivity of the inactivation mutant to UV irradiation, MMC and peroxide was complemented by an extrachromosomal copy of uvrA(Bbu). We conclude that uvrA(Bbu) is functional in B. burgdorferi.
FEMS Microbiology Letters 01/2011; 317(2):172-80. · 2.04 Impact Factor
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ABSTRACT: Salmon aquaculture was one of the major growing and exporting industries in Chile. Its development was accompanied by an increasing and excessive use of large amounts of antimicrobials, such as quinolones, tetracyclines and florfenicol. The examination of the sanitary conditions in the industry as part of a more general investigation into the uncontrolled and extensive dissemination of the ISA virus epizootic in 2008, found numerous and wide-ranging shortcomings and limitations in management of preventive fish health. There was a growing industrial use of large amounts of antimicrobials as an attempt at prophylaxis of bacterial infections resulting from widespread unsanitary and unhealthy fish rearing conditions. As might be expected, these attempts were unsuccessful and this heavy antimicrobial use failed to prevent viral and parasitic epizootics. Comparative analysis of the amounts of antimicrobials, especially quinolones, consumed in salmon aquaculture and in human medicine in Chile robustly suggests that the most important selective pressure for antibiotic resistant bacteria in the country will be excessive antibiotic use in this industry. This excessive use will facilitate selection of resistant bacteria and resistance genes in water environments. The commonality of antibiotic resistance genes and the mobilome between environmental aquatic bacteria, fish pathogens and pathogens of terrestrial animals and humans suggests that horizontal gene transfer occurs between the resistome of these apparently independent and isolated bacterial populations. Thus, excessive antibiotic use in the marine environment in aquaculture is not innocuous and can potentially negatively affect therapy of bacterial infections of humans and terrestrial animals.
Revista medica de Chile 01/2011; 139(1):107-18. · 0.33 Impact Factor
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ABSTRACT: BmpA is an immunodominant protein of Borrelia burgdorferi as well as an arthritogenic factor. Rabbit antirecombinant BmpA (rBmpA) antibodies were raised, characterized by assaying their cross reactivity with rBmpB, rBmpC and rBmpD, and then rendered monospecific by absorption with rBmpB. This monospecific reagent reacted only with rBmpA in dot immunobinding and detected a single 39 kDa, pI 5.0, spot on two-dimensional immunoblots. It was used to assess the BmpA cellular location. BmpA was present in both detergent-soluble and -insoluble fractions of Triton X-114 phase-partitioned borrelial cells, suggesting that it was a membrane lipoprotein. Immunoblots of proteinase K-treated intact and Triton X-100 permeabilized cells showed digestion of BmpA in intact cells, consistent with surface exposure. This exposure was confirmed by dual-label immunofluorescence microscopy of intact and permeabilized borrelial cells. Conservation and surface localization of BmpA in all B. burgdorferi sensu lato genospecies could point to its playing a key role in this organism's biology and pathobiology.
FEMS Microbiology Letters 08/2010; 309(1):77-83. · 2.04 Impact Factor
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Infection and immunity 11/2008; 76(10):4792. · 4.21 Impact Factor
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Felipe C Cabello
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ABSTRACT: The influence of the work of Dr. Guillermo Contreras Da Silva and his colaborators on the evolution of microbiology in Chile is briefly analyzed. Dr. Contreras was trained in modern virology at Yale University with Dr. J. Melnick under the sponsorhip of the Rockefeller Foundation. During this training, he used serological methods to classify Cocksakie viruses. After his return to Chile, he studied the epidemiology of enteroviruses, including poliovirus. His laboratory, the country's first in modern virology, took an active role in Chile's first Sabin polio vaccination in 1961. Dr. Contreras and his group transformed the teaching and the character of microbiology in Chile from a descriptive medically oriented discipline into an autonomous, quantitative and experimental science. They modernized microbiology with the introduction of molecular biology and microbial genetics and fostered collaborations with allied biological sciences. Dr. Contreras was a Guggenheim Fellow, and until his retirement, was the Chief of the Viral Products Division, Bureau of Biologies, Ottawa, Canada.
Revista medica de Chile 03/2008; 136(2):256-60. · 0.33 Impact Factor
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Felipe C Cabello
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ABSTRACT: Recent clinical and epidemiológical information, an analysis of the literature, and study of the technical aspects of Chilean salmon aquaculture indicate that this activity has the ability to expand the range of diphyllobothriasis caused by the fish tapeworm Diphyllobothrium latum. Evidence for expansion of the range of the fish tapeworm includes the emergences of clinical cases in Brazil related to consumption of salmon produced in Chile. Expansion of the range of this parasite is also suggested by an increase of its geographical range in Chile, beyond its previously endemic foci in the lakes of Regions IX and X. Prevention of further dissemination of this parasitic disease rests on an improvement of sanitation and sewage disposal around the lakes of Regions IX, X and XI in Chile, improvement in aquaculture methods including curtailing the use of fish tapeworm-contaminated lakes to grow juveniles forms of salmonids and more measures to decrease the number of salmonid escapees from marine pens to prevent their return to rivers and lakes carrying the infestation. Moreover, tracking the origin of juveniles in marketed salmon, determining the presence of plerocercoids in them, and increased education of the public regarding the potential dangers of eating raw fish should also be implemented. Only by stimulating the dialogue between the industry, consumers and state regulators will it be possible to implement appropriate measures to prevent further expansion of this parasitic disease by salmon aquaculture.
Revista medica de Chile 09/2007; 135(8):1064-71. · 0.33 Impact Factor
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ABSTRACT: Borrelia burgdorferi, the tick-transmitted etiologic agent of Lyme borreliosis, can colonize and persist in multiple tissue sites despite vigorous host immune responses. The extracellular matrix appears to provide a protective niche for the spirochete. Recent studies in mice suggest that B. burgdorferi interacts in various ways with collagen and its associated molecules, exploiting molecular and structural features to establish microcolonial refugia. Better knowledge of the genetic and structural bases for these interactions of B. burgdorferi with the extracellular matrix will be required before an understanding of the persistence of B. burgdorferi in the tissues and development of chronic infections can be achieved.
Trends in Microbiology 09/2007; 15(8):350-4. · 7.91 Impact Factor
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Felipe C Cabello
Emerging infectious diseases 02/2007; 13(1):169-71. · 6.17 Impact Factor
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Felipe C Cabello
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ABSTRACT: The accelerated growth of finfish aquaculture has resulted in a series of developments detrimental to the environment and human health. The latter is illustrated by the widespread and unrestricted use of prophylactic antibiotics in this industry, especially in developing countries, to forestall bacterial infections resulting from sanitary shortcomings in fish rearing. The use of a wide variety of antibiotics in large amounts, including non-biodegradable antibiotics useful in human medicine, ensures that they remain in the aquatic environment, exerting their selective pressure for long periods of time. This process has resulted in the emergence of antibiotic-resistant bacteria in aquaculture environments, in the increase of antibiotic resistance in fish pathogens, in the transfer of these resistance determinants to bacteria of land animals and to human pathogens, and in alterations of the bacterial flora both in sediments and in the water column. The use of large amounts of antibiotics that have to be mixed with fish food also creates problems for industrial health and increases the opportunities for the presence of residual antibiotics in fish meat and fish products. Thus, it appears that global efforts are needed to promote more judicious use of prophylactic antibiotics in aquaculture as accumulating evidence indicates that unrestricted use is detrimental to fish, terrestrial animals, and human health and the environment.
Environmental Microbiology 08/2006; 8(7):1137-44. · 5.84 Impact Factor
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ABSTRACT: Ixodes scapularis ticks play an important role in the transmission of a wide variety of pathogens between various mammalian species, including humans. Pathogens transmitted by ticks include Borrelia, Anaplasma and Babesia. Although ticks may harbour both pathogenic and non-pathogenic microflora, little is known about how the diversity of the microflora within ticks may influence the transmission of pathogens. To begin addressing this question, we examined the composition of bacterial communities present in Ixodes scapularis collected from Westchester and Dutchess Counties, New York State, at different developmental and nutritional stages. Genetic fingerprints of bacterial populations were generated by temporal temperature gradient gel electrophoresis (TTGE) separation of individual polymerase chain reaction (PCR)-amplified 16S rRNA gene fragments, followed by DNA sequence analysis for bacterial identification. The fingerprints of the TTGE bands were grouped into five clusters. The most abundant DNA sequence found in all the samples was Rickettsia, followed by Pseudomonas and Borrelia. Ralstonia, Anaplasma, Enterobacterias, Moraxella, Rhodococcus and uncultured proteobacterium were present as well. We also determined the prevalence of Anaplasma phagocytophilum and Borrelia burgdorferi by PCR and DNA sequence analysis. Statistical analyses indicated significant variations in the bacterial communities depending on tick developmental stage and degree of engorgement. We suggest that these two elements affect microbial diversity within the tick and may in turn influence pathogen transmission to humans and animals after tick bite.
Environmental Microbiology 06/2006; 8(5):761-72. · 5.84 Impact Factor
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ABSTRACT: ftsZ is essential for cell division in many microorganisms. In Escherichia coli and Bacillus subtilis, FtsZ plays a role in ring formation at the leading edge of the cell division septum. An ftsZ homologue is present in the Borrelia burgdorferi genome (ftsZ(Bbu)). Its gene product (FtsZ(Bbu)) is strongly homologous to other bacterial FtsZ proteins, but its function has not been established. Because loss-of-function mutants of ftsZ(Bbu) might be lethal, the tetR/tetO system was adapted for regulated control of this gene in B. burgdorferi. Sixty-two nucleotides of an ftsZ(Bbu) antisense DNA sequence under the control of a tetracycline-responsive modified hybrid borrelial promoter were cloned into pKFSS1. This construct was electroporated into a B. burgdorferi host strain carrying a chromosomally located tetR under the control of the B. burgdorferi flaB promoter. After induction by anhydrotetracycline, expression of antisense ftsZ RNA resulted in generation of filamentous B. burgdorferi that were unable to divide and grew more slowly than uninduced cells. To determine whether FtsZ(Bbu) could interfere with the function of E. coli FtsZ, ftsZ(Bbu) was amplified from chromosomal DNA and placed under the control of the tetracycline-regulated hybrid promoter. After introduction of the construct into E. coli and induction with anhydrotetracycline, overexpression of ftsZ(Bbu) generated a filamentous phenotype. This suggested interference of ftsZ(Bbu) with E. coli FtsZ function and confirmed the role of ftsZ(Bbu) in cell division. This is the first report of the generation of a B. burgdorferi conditional lethal mutant equivalent by tetracycline-controlled expression of antisense RNA.
Journal of Bacteriology 04/2006; 188(5):1969-78. · 3.83 Impact Factor
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ABSTRACT: Abstract
The development of genetic systems for B. burgdorferi has allowed identification of several regulatory and structural genes involved in the ability of this bacterium to colonize and disseminate in its arthropod and mammalian hosts. Progress has been slow as a result of the complex biology of this pathogen, and its genetic distance from Gram-positive and Gram-negative bacteria has impeded easy adaptation to B. burgdorferi of genetic tools developed for other bacteria. We have repeatedly encountered these issues in our attempts to use molecular genetic tools to analyze the role of the members of the paralogous bmp gene family in the biology and virulence of B. burgdorferi. For example, an attempt to characterize the role of bmpC in virulence using a bmpC deletion mutant of an infectious B. burgdorferi 297 strain and an extrachromosomally complemented derivative of this mutant was only partially successful. While deletion of bmpC did not decrease infectivity in mice, it significantly decreased B. burgdorferi DNA in joints and arthritis. Extrachromosomal complementation of this null mutation reduced infectivity and did not restore tissue pathogenicity. To overcome these problems, we have adapted the Tet system of controlled gene expression developed for other bacteria and eukaryotic cells to manipulate gene expression in B. burgdorferi. In a two plasmid Tet system, where one plasmid contains the TetR repressor fused to the flaB promoter and the other plasmid contains a hybrid borrelial promoter with a tet operator (Ptetl-1), expression of the gene fused to the Ptetl-1 promoter (truncated BmpA, green fluorescent protein) is regulated by anhydrotetracycline in a concentration dependent manner over a wide range of concentrations. Because the two plasmid Tet system has some inherent instability manifested by escape from TetR repression and potential plasmid loss requiring continuous antibiotic selection, we constructed a B. burgdorferi strain containing the flaB/tetR fusion inserted in a nonessential gene (luxS) and designed a new hybrid promoter containing two instead of one tet operators (Ptetl-2). The functionality of this Tet system was demonstrated by manipulating expression of the B. burgdorferi bmpA gene. These findings strongly suggest that the Tet system can be used in B. burgdorferi to manipulate gene expression and open the door to manipulating gene expression by antisense RNA technology and gene fusions that will permit isolation of conditional lethal mutants in B. burgdorferi.
NATO Science Series, I: Life and Behavioural Sciences. Volume 373, 2006. Molecular Biology of Spirochetes. ISBN 978-1-58603-665-2. 01/2006;
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ABSTRACT: Serologic tests play an important role in diagnosis of typhoid fever. In an effort to develop a more defined reagent for these tests, purified Salmonella enterica serovar Typhi (ST) O:1,9,12 polysaccharide was conjugated to human serum albumin (HSA), and the conjugate was purified chromatographically to yield a reagent with 2 moles ST O polysaccharide per mole HSA. In 40 patients with bacteriologically confirmed typhoid fever, significant dot immunobinding titers (> or =20,000) were present in 28 (70%) tested with 100 ng of ST O antigen-HSA (ST O-HSA) conjugate, in 38 (95%) tested with 100 ng of ST lipopolysaccharide, and in 16 (40%) tested with purified unconjugated ST O chains. In sera from 22 patients with other nontyphoid fevers, 2 (9.1%) had such reactivities with 100 ng of ST O-HSA, 1 (4.5%) had such reactivity with 100 ng of ST lipopolysaccharide (4.5%), and none reacted with 100 ng of unconjugated ST O chains. None of the 17 healthy-control sera reacted significantly with any of the ST reagents. None of the patient or control sera reacted with unconjugated HSA. The sensitivity of dot immunobinding for typhoid fever was 70% with 100 ng of ST O-HSA, somewhat lower than that with 100 ng of ST lipopolysaccharide (95%) but similar to that of the Widal H agglutination test with a > or =1/160 cutoff (74%). Specificities of these tests were 91%, 95%, and 86%, respectively. These preliminary results suggest that ST O polysaccharide-protein conjugates could provide a nontoxic, easily quality-controlled synthetic reagent for analysis of human immune responses to ST as well as for the development of new diagnostics and vaccines for typhoid fever.
Journal of Clinical Microbiology 10/2005; 43(9):4545-50. · 4.15 Impact Factor
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ABSTRACT: Borrelia burgdorferi contains one 16S rRNA gene and two tandem sets of 23S and 5S rRNA genes located in a single chromosomal region. This unusual rRNA gene organization has been speculated to be involved in the slow growth of this organism. Because we were repeatedly unable to isolate a 23S ribosomal mutant in B. burgdorferi by allelic exchange, we developed a transposition mutagenesis system for this bacterium. To this end, Himar1 transposase is expressed in B. burgdorferi from a resident plasmid containing an erythromycin resistance marker, and this strain is then electroporated with suicide plasmids containing mariner transposons and kanamycin resistance genes expressible in B. burgdorferi. This system permitted us to generate hundreds of erythromycin/kanamycin-resistant B. burgdorferi clones with each of three suicide plasmids. DNA sequencing of several kanamycin-resistant clones generated with one of the suicide plasmids showed stable and random insertion of the transposon into the B. burgdorferi chromosomal and plasmid genome. One mutant was inactivated in rrlA (23S rRNA), another in ftsJ (rrmJ). rrlA disruption had no effect on growth rate under a wide range of culture conditions, but disruption of ftsJ interfered significantly with growth rate and bacterial morphology. These data show it is possible to isolate random and stable B. burgdorferi transposition mutants for physiological analysis of this pathogenic spirochete.
Gene 09/2005; 357(1):63-72. · 2.34 Impact Factor
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ABSTRACT: The Bmp proteins are a paralogous family of chromosomally encoded Borrelia burgdorferi lipoproteins. They have similar predicted immunogenicities and similar electrophoretic mobilities by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. P39 reactivity against Borrelia burgdorferi lysate in immunoblots of Lyme disease patients has long been identified with reactivity to BmpA, but responses to other Bmp proteins have not been examined. To determine if patients with Lyme disease developed such responses, immunoglobulin G (IgG) anti-Bmp reactivity in patient and control sera was studied by using soluble recombinant Bmp (rBmp) proteins expressed in Escherichia coli. Although some patient sera contained IgG immunoblot and immunodot reactivities against all four Bmp proteins, analysis of IgG anti-Bmp fine specificity by a competitive enzyme-linked immunosorbent assay with graded doses of soluble homologous and heterologous rBmp proteins showed that only the responses to BmpA, BmpB, and BmpD were specific. This suggests that at least three of the four Bmp proteins are expressed by B. burgdorferi in infected patients and that specific antibodies to them are likely to be present in the P39 band in some patients.
Clinical and Diagnostic Laboratory Immunology 09/2005; 12(8):935-40. · 2.51 Impact Factor
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ABSTRACT: The global transcriptional regulator (p)ppGpp (guanosine-3'-diphosphate-5'-triphosphate and guanosine-3',5'-bisphosphate, collectively) produced by the relA and spoT genes in Escherichia coli allows bacteria to adapt to different environmental stresses. The genome of Borrelia burgdorferi encodes a single chromosomal rel gene (BB0198) (B. burgdorferi rel [rel(Bbu)]) homologous to relA and spoT of E. coli. Its role in (p)ppGpp synthesis, bacterial growth, and modulation of gene expression has not been studied in detail. We constructed a rel(Bbu) deletion mutant in an infectious B. burgdorferi 297 strain and isolated an extrachromosomally complemented derivative of this mutant. The mutant did not synthesize rel(Bbu) mRNA, Rel(Bbu) protein, or (p)ppGpp. This synthesis was restored in the complemented derivative, confirming that rel(Bbu) is necessary and sufficient for (p)ppGpp synthesis and degradation in B. burgdorferi. The rel(Bbu) mutant grew well during log phase in complete BSK-H but reached lower cell concentrations in the stationary phase than the wild-type parent, suggesting that (p)ppGpp may be an important factor in the ability of B. burgdorferi to adapt to stationary phase. Deletion of rel(Bbu) did not eliminate the temperature-elicited OspC shift, nor did it alter bmp gene expression or B. burgdorferi antibiotic susceptibility. Although deletion of rel(Bbu) eliminated B. burgdorferi virulence for mice, which was not restored by complementation, we suggest that rel(Bbu)-dependent accumulation of (p)ppGpp may be important for in vivo survival of this pathogen.
Infection and Immunity 09/2005; 73(8):4972-81. · 4.16 Impact Factor
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Felipe C Cabello
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ABSTRACT: Industrial antibiotic usage in agribusinesses and aquaculture is the force that drives the evolution of antibiotic resistant bacteria that produce human and animal disease in many countries. Several studies have demonstrated that most of the industrial use of antibiotics is unnecessary, and that modernization and hygienic changes can reduce this use of antibiotics without negative economic impact. In Chile, industrial aquaculture of salmon has expanded rapidly in the last 20 years becoming a major export business. The exponential growth of this industry has been accompanied by an unrestricted heavy usage of antibiotics in the aquatic environments of lakes, rivers and the ocean, and its impact is being felt in the emergence of antibiotic-resistant bacteria around aquaculture sites and a decrease in the plancktonic diversity in the same areas. The passage of antibiotic resistance genes from aquatic bacteria to human and animal pathogens has been demonstrated, indicating that industrial use of antibiotics in aquaculture affects negatively the antibiotic therapy of human and animal bacterial infections. The Chilean situation triggers important concerns because it includes the use of fluoroquinolones in aquaculture, that are not biodegradable and are able to remain in the environment for years as well as being still effective in treating human infections. The use of large volumes of a wide spectrum of antibiotics in an aquatic environment heavily contaminated with human and animal pathogens also amplifies the opportunities for gene transfer among bacteria, facilitating the emergence of antibiotic resistance and more pathogenic bacterial recombinants. The detection of residual antibiotics in salmons marketed for human consumption that can modify the normal flora of the population also suggests the need for controls on this antibiotic usage and on the presence of residual antibiotics in aquaculture food products. This important problem of public health demands an active dialogue between government officials responsible for protecting public health, aquaculture industry representatives, politicians, consumers and professionals dealing with these matters.
Revista medica de Chile 09/2004; 132(8):1001-6. · 0.33 Impact Factor
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ABSTRACT: Borrelia burgdorferi binds strongly to the extracellular matrix and cells of the connective tissue, a binding apparently mediated by specific proteins and proteoglycans. We investigated the interactions between B. burgdorferi cells and intact type I collagen using hydrated lattices that reproduce features of in vivo collagen matrices. B. burgdorferi cells of several strains adhered avidly to these acellular matrices by a mechanism that was not mediated by decorin or other proteoglycans. Moreover, following adhesion to these matrices, B. burgdorferi grew and formed microcolonies. The collagen used in these studies was confirmed to lack decorin by immunoblot analysis; B. burgdorferi cells lacking the decorin adhesin bound readily to intact collagen matrices. B. burgdorferi also bound to collagen lattices that incorporated enzymes that degraded glycosaminoglycan chains in any residual proteoglycans. Binding of the bacteria to intact collagen was nonetheless specific, as bacteria did not bind agar and showed only minimal binding to bovine serum albumin, gelatin, pepsinized type I collagen, and intact collagen that had been misassembled under nonphysiological pH and ionic-strength conditions. Proteinase K treatment of B. burgdorferi cells decreased the binding, as did a lack of flagella, suggesting that surface-exposed proteins and motility may be involved in the ability of B. burgdorferi to interact with intact collagen matrices. The high efficiency of binding of B. burgdorferi strains to intact collagen matrices permits replacement of the commonly used isotopic binding assay with visual fluorescent microscopic assays and will facilitate future studies of these interactions.
Infection and Immunity 07/2004; 72(6):3138-46. · 4.16 Impact Factor
