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Cuenca-Estrella M, Ruiz-Díez B, Martínez-Suárez JV, Monzón A, Rodríguez-Tudela JL. Comparative in-vitro activity of voriconazole (UK-109,496) and six other antifungal agents against clinical isolates of Scedosporium prolificans and Scedosporium apiospermum. J Antimicrob Chemother 1999; 43:149-51. [PMID: 10381115 DOI: 10.1093/jac/43.1.149] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We report the in-vitro susceptibility of 27 clinical isolates of Scedosporium apiospermum and 43 of Scedosporium prolificans. S. apiospermum was resistant to fluconazole and flucytosine, with variable susceptibility to amphotericin B, itraconazole, ketoconazole and susceptible to miconazole. Voriconazole was much more active than fluconazole and flucytosine, more active than amphotericin B, itraconazole and ketoconazole and was as active as miconazole against S. apiospermum isolates. Voriconazole and the other six antifungal agents showed low activity against S. prolificans isolates.
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Comparative Study |
26 |
165 |
2
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Martínez-Suárez JV, Ortiz S, López-Alonso V. Potential Impact of the Resistance to Quaternary Ammonium Disinfectants on the Persistence of Listeria monocytogenes in Food Processing Environments. Front Microbiol 2016; 7:638. [PMID: 27199964 PMCID: PMC4852299 DOI: 10.3389/fmicb.2016.00638] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 04/18/2016] [Indexed: 11/13/2022] Open
Abstract
The persistence of certain strains of Listeria monocytogenes, even after the food processing environment has been cleaned and disinfected, suggests that this may be related to phenomena that reduce the concentration of the disinfectants to subinhibitory levels. This includes (i) the existence of environmental niches or reservoirs that are difficult for disinfectants to reach, (ii) microorganisms that form biofilms and create microenvironments in which adequate concentrations of disinfectants cannot be attained, and (iii) the acquisition of resistance mechanisms in L. monocytogenes, including those that lead to a reduction in the intracellular concentration of the disinfectants. The only available data with regard to the resistance of L. monocytogenes to disinfectants applied in food production environments refer to genotypic resistance to quaternary ammonium compounds (QACs). Although there are several well-characterized efflux pumps that confer resistance to QACs, it is a low-level resistance that does not generate resistance to QACs at the concentrations applied in the food industry. However, dilution in the environment and biodegradation result in QAC concentration gradients. As a result, the microorganisms are frequently exposed to subinhibitory concentrations of QACs. Therefore, the low-level resistance to QACs in L. monocytogenes may contribute to its environmental adaptation and persistence. In fact, in certain cases, the relationship between low-level resistance and the environmental persistence of L. monocytogenes in different food production chains has been previously established. The resistant strains would have survival advantages in these environments over sensitive strains, such as the ability to form biofilms in the presence of increased biocide concentrations.
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Review |
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116 |
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Cuenca-Estrella M, Rodríguez-Tudela JL, Mellado E, Martínez-Suárez JV, Monzón A. Comparison of the in-vitro activity of voriconazole (UK-109,496), itraconazole and amphotericin B against clinical isolates of Aspergillus fumigatus. J Antimicrob Chemother 1998; 42:531-3. [PMID: 9818755 DOI: 10.1093/jac/42.4.531] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Voriconazole was compared with amphotericin B and itraconazole by a modification of the NCCLS microdilution reference method for yeasts against 62 clinical isolates of Aspergillus fumigatus. MICs of voriconazole were slightly lower than those of amphotericin B and itraconazole. The MIC of voriconazole at which 90% of isolates were inhibited was 1 mg/L and the MIC range was 0.25-2 mg/L. Voriconazole is a new antifungal agent with potential for use in the treatment of A. fumigatus infections.
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Comparative Study |
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72 |
4
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Espinel-Ingroff A, Rodríguez-Tudela JL, Martínez-Suárez JV. Comparison of two alternative microdilution procedures with the National Committee for Clinical Laboratory Standards reference macrodilution method M27-P for in vitro testing of fluconazole-resistant and -susceptible isolates of Candida albicans. J Clin Microbiol 1995; 33:3154-8. [PMID: 8586692 PMCID: PMC228663 DOI: 10.1128/jcm.33.12.3154-3158.1995] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The National Committee for Clinical Laboratory Standards has proposed a reference broth macrodilution method for in vitro antifungal susceptibility testing of yeasts (the M27-P method). This method is cumbersome and time-consuming and includes MIC endpoint determination by the visual and subjective inspection of growth inhibition after 48 h of incubation. Two alternative microdilution procedures for MIC endpoint determination, a spectrophotometric MIC endpoint test that evaluates 80% growth inhibition by the drug and a colorimetric method with an oxidation-reduction indicator (Alamar Blue), were compared with the M27-P method for fluconazole susceptibility testing of 45 susceptible and resistant isolates of Candida albicans. The spectrophotometric method was performed with RPMI 1640 medium with 2% glucose, and the other two tests were performed with plain RPMI 1640 medium. All tests were incubated at 35 degrees C. Excellent agreement was demonstrated between the M27-P method and both 24-h microdilution tests (97.7%) as well as between the two microdilution tests (95.5%). Also, there was agreement in the detection in vivo of fluconazole resistance by the three methods. These preliminary data indicate that both microdilution methods may serve as less subjective alternatives to the M27-P method for the determination of fluconazole MIC endpoints.
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research-article |
30 |
64 |
5
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Rodríguez-Tudela JL, Martínez-Suárez JV, Dronda F, Laguna F, Chaves F, Valencia E. Correlation of in-vitro susceptibility test results with clinical response: a study of azole therapy in AIDS patients. J Antimicrob Chemother 1995; 35:793-804. [PMID: 7559191 DOI: 10.1093/jac/35.6.793] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The in-vitro susceptibilities of 40 clinical isolates of Candida albicans to ketoconazole and fluconazole were determined and an attempt was made to correlate these data with the clinical responses of the patients from whom the strains were originally isolated to treatment with these agents. Of 40 patients with the acquired immunodeficiency syndrome (AIDS) with oropharyngeal and/or oesophageal candidosis, 21 received ketoconazole and 19 fluconazole. Susceptibility testing was performed by a microbroth dilution method with RPMI-2% glucose medium according to the recommendations of the National Committee for Clinical Laboratory Standards; growth inhibition was estimated spectrophotometrically and the MIC endpoint was defined in terms of the IC1/2. The MICs of 236 additional strains of C. albicans, which were also isolated from AIDS patients, were used to establish a susceptibility profile for this species. On the basis of the susceptibility test results and the clinical responses of the 40 patients, the following tentative breakpoints for ketoconazole and fluconazole are proposed: patients with infections caused by C. albicans strains with MICs of ketoconazole and fluconazole or < or = 0.001 and < or = 0.25 mg/L respectively would be expected to respond to treatment with these agents and isolates with MICs which meet these criteria are therefore classified as susceptible; patients with infections caused by strains with MICs of ketoconazole and fluconazole of > or = 0.06 and > or = 16.0 mg/L respectively would not be expected to respond to treatment with these agents and isolates with MICs which meet these criteria are therefore classified as resistant; the response of patients with infections caused by strains with MICs of ketoconazole and fluconazole of 0.003-0.03 and 0.5-8.0 mg/L respectively cannot be reliably predicted and isolates with MICs which fall within these ranges are therefore classified as being of indeterminate susceptibility. The present study demonstrates that the results of in-vitro susceptibility testing with RPMI-2% glucose broth correlate with the clinical response to therapy and can be used to facilitate optimal treatment in AIDS patients with oropharyngeal and/or oesophageal candidosis.
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Clinical Trial |
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49 |
6
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Rodríguez-Tudela JL, Berenguer J, Martínez-Suárez JV, Sanchez R. Comparison of a spectrophotometric microdilution method with RPMI-2% glucose with the National Committee for Clinical Laboratory Standards reference macrodilution method M27-P for in vitro susceptibility testing of amphotericin B, flucytosine, and fluconazole against Candida albicans. Antimicrob Agents Chemother 1996; 40:1998-2003. [PMID: 8878570 PMCID: PMC163462 DOI: 10.1128/aac.40.9.1998] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The National Committee for Clinical Laboratory Standards has proposed a reference broth macrodilution method for in vitro antifungal susceptibility testing of yeasts (the M27-P method). This method is cumbersome and time-consuming and includes MIC endpoint determination by visual and subjective inspection of growth inhibition after 48 h of incubation. An alternative microdilution procedure was compared with the M27-P method for determination of the amphotericin B, flucytosine, and fluconazole susceptibilities of 8 American Type Culture Collection strains (6 of them were quality control or reference strains) and 50 clinical isolates of candida albicans. This microdilution method uses as culture medium RPMI 1640 supplemented with 18 g of glucose per liter (RPMI-2% glucose). Preparation of drugs, basal medium, and inocula was done by following the recommendations of the National Committee for Clinical Laboratory Standards. The MIC endpoint was calculated objectively from the turbidimetric data read at 24 h. Increased growth of C. albicans in RPMI-2% glucose and its spectrophotometric reading allowed for the rapid (24 h) and objective calculation of MIC endpoints compared with previous microdilution methods with standard RPMI 1640. Nevertheless, good agreement was shown between the M27-P method and this microdilution test. The MICs obtained for the quality control or reference strains by the microdilution method were in the ranges published for those strains. For clinical isolates, the percentages of agreement were 100% for amphotericin B and fluconazole and 98.1% for flucytosine. These data suggest that this microdilution method may serve as a less subjective and more rapid alternative to the M27-P method for antifungal susceptibility testing of yeasts.
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research-article |
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7
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Ortiz S, López V, Martínez-Suárez JV. The influence of subminimal inhibitory concentrations of benzalkonium chloride on biofilm formation by Listeria monocytogenes. Int J Food Microbiol 2014; 189:106-12. [PMID: 25136789 DOI: 10.1016/j.ijfoodmicro.2014.08.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 07/19/2014] [Accepted: 08/02/2014] [Indexed: 12/14/2022]
Abstract
Disinfectants, such as benzalkonium chloride (BAC), are commonly used to control Listeria monocytogenes and other pathogens in food processing plants. Prior studies have demonstrated that the resistance to BAC of L. monocytogenes was associated with the prolonged survival of three strains of molecular serotype 1/2a in an Iberian pork processing plant. Because survival in such environments is related to biofilm formation, we hypothesised that the influence of BAC on the biofilm formation potential of L. monocytogenes might differ between BAC-resistant strains (BAC-R, MIC≥10mg/L) and BAC-sensitive strains (BAC-S, MIC≤2.5mg/L). To evaluate this possibility, three BAC-R strains and eight BAC-S strains, which represented all of the molecular serotype 1/2a strains detected in the sampled plant, were compared. Biofilm production was measured using the crystal violet staining method in 96-well microtitre plates. The BAC-R strains produced significantly (p<0.05) less biofilm than the BAC-S in the absence of BAC, independent of the rate of planktonic growth. In contrast, when the biofilm values were measured in the presence of BAC, one BAC-R strain (S10-1) was able to form biofilm at 5mg/L of BAC, which prevented biofilm formation among the rest of the strains. A genetic determinant of BAC resistance recently described in L. monocytogenes (Tn6188) was detected in S10-1. When a BAC-S strain and its spontaneous mutant BAC-R derivative were compared, resistance to BAC led to biofilm formation at 5mg/L of BAC and to a significant (p<0.05) stimulation of biofilm formation at 1.25mg/L of BAC, which significantly (p<0.05) reduced the biofilm level in the parent BAC-S strain. Our results suggest that the effect of subminimal inhibitory concentrations of BAC on biofilm production by L. monocytogenes might differ between strains with different MICs and even between resistant strains with similar MICs but different genetic determinants of BAC resistance. For BAC-R strains similar to S10-1, subminimal inhibitory BAC may represent an advantage, compensating for the weak biofilm formation level that might be associated with resistance. Biofilm formation in the presence of increased subminimal inhibitory concentrations of the disinfectant may represent an important attribute among certain resistant and persistent strains of L. monocytogenes.
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Research Support, Non-U.S. Gov't |
11 |
48 |
8
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Díaz-Guerra TM, Martínez-Suárez JV, Laguna F, Rodríguez-Tudela JL. Comparison of four molecular typing methods for evaluating genetic diversity among Candida albicans isolates from human immunodeficiency virus-positive patients with oral candidiasis. J Clin Microbiol 1997; 35:856-61. [PMID: 9157142 PMCID: PMC229690 DOI: 10.1128/jcm.35.4.856-861.1997] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Candida albicans strain delineation by karyotyping. NotI restriction pattern analysis, hybridization with specific probe 27A, and PCR fingerprinting with the phage M13 core sequence were performed with 30 isolates from the oral cavities of 30 human immunodeficiency virus (HIV)-infected patients and 8 reference strains. Within the panel of clinical isolates, 20 were geographically related, although 10 isolates were susceptible to fluconazole and 10 isolates were resistant to fluconazole. The remaining isolates used in this study were fluconazole resistant and geographically unrelated. A composite DNA type was defined for each of the strains as the combination of types obtained by the four molecular methods. By this procedure, a great diversity of DNA types was found among isolates from the oropharynges of HIV-infected individuals with oral candidiasis. This diversity was not reduced when isolates were evaluated on the basis of whether they came from the same geographical locale and whether they were fluconazole resistant. These data refute the idea of a clonal origin for fluconazole-resistant strains among HIV-positive patients. Karyotyping was the least discriminatory method, yielding 19 DNA types among the 38 strains analyzed. Conversely, hybridization with the 27A probe showed a unique DNA pattern for each of the strains examined in this study. Our results demonstrate that at least two different molecular methods are needed for Candida albicans typing and that there is a great deal of strain variation within the species, irrespective of place of origin or antifungal resistance patterns.
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research-article |
28 |
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9
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Dronda F, Alonso-Sanz M, Laguna F, Chaves F, Martínez-Suárez JV, Rodríguez-Tudela JL, González-López A, Valencia E. Mixed oropharyngeal candidiasis due to Candida albicans and non-albicans Candida strains in HIV-infected patients. Eur J Clin Microbiol Infect Dis 1996; 15:446-52. [PMID: 8839637 DOI: 10.1007/bf01691310] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In order to determine the clinical significance of mixed oropharyngeal candidiasis (Candida albicans plus a non-albicans strain of Candida) in patients infected with HIV-1, a retrospective chart review was done in 12 HIV-1-infected patients with a clinical episode of oropharyngeal candidiasis, in whom a mixed culture of Candida albicans (found to be fluconazole-sensitive) plus a non-albicans species of Candida was obtained from their oral cavities. This group was compared with 26 HIV-positive patients (control group) with oropharyngeal candidiasis due to Candida albicans (found to be fluconazole-sensitive). Antifungal susceptibility testing was performed by a broth microdilution test with RPMI-2% glucose. A fungal strain was considered fluconazole-sensitive if its MIC was < 0.5 micrograms/ml. Both the study and control groups had similar clinical and demographic characteristics. All the patients were severely immunocompromised, with a mean CD4+ lymphocyte count of 63/mm3 (95% CI 41-84) and 80/mm3 (95% CI 25-135) in the study and control groups, respectively. In the study group, seven patients had Candida albicans and Candida krusei in their oral cavity, four had Candida albicans and Candida glabrata, and one had Candida albicans and Candida tropicalis. Antifungal therapy consisted of ketoconazole (5 patients in the study group, 14 in the control group) or fluconazole (7 patients in the study group, 12 in the control group); no statistically significant difference in clinical outcome was observed. Fungal strain persistence after therapy was frequently observed in both groups. It is concluded that non-albicans strains of Candida, less sensitive to azole drugs than their Candida albicans counterparts, are not clinically relevant in episodes of mixed oropharyngeal candidiasis in HIV-1-infected patients.
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38 |
10
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Rodríguez-Melcón C, Capita R, Rodríguez-Jerez JJ, Martínez-Suárez JV, Alonso-Calleja C. Effect of Low Doses of Disinfectants on the Biofilm-Forming Ability of Listeria monocytogenes. Foodborne Pathog Dis 2019; 16:262-268. [DOI: 10.1089/fpd.2018.2472] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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30 |
11
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Ruiz-Díez B, Martín-Díez F, Rodríguez-Tudela JL, Alvárez M, Martínez-Suárez JV. Use of random amplification of polymorphic DNA (RAPD) and PCR-fingerprinting for genotyping a Scedosporium prolificans (inflatum) outbreak in four leukemic patients. Curr Microbiol 1997; 35:186-90. [PMID: 9236303 DOI: 10.1007/s002849900236] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Four isolates of the pathogenic fungus Scedosporium prolificans (inflatum), causing a previously reported nosocomial outbreak in four leukemic patients, were typed by random amplification of polymorphic DNA (RAPD) with two different 10-mer primers and PCR-fingerprinting with the core sequence of phage M13 as a single primer. Both techniques allowed 10 additional clinical isolates of Scedosporium prolificans from different areas of Spain, including Scedosporium prolificans NCPF 2884, to be classified into 10 different molecular types. The four outbreak isolates consisted of three molecular types with two patients sharing a similar strain, and the remaining two patients infected by two different strains.
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28 |
12
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López-Campos G, Martínez-Suárez JV, Aguado-Urda M, López-Alonso V. Detection, Identification, and Analysis of Foodborne Pathogens. SPRINGERBRIEFS IN FOOD, HEALTH, AND NUTRITION 2012. [DOI: 10.1007/978-1-4614-3250-0_2] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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13 |
27 |
13
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López V, Ortiz S, Corujo A, López P, Poza D, Navas J, Moreno R, Martínez-Suárez JV. Different contamination patterns of lineage I and II strains of Listeria monocytogenes in a Spanish broiler abattoir. Poult Sci 2008; 87:1874-82. [PMID: 18753457 DOI: 10.3382/ps.2007-00417] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The purpose of this study was to determine whether genetically similar or diverse strains of Listeria monocytogenes colonize the environment and carcasses in a single Spanish broiler abattoir over time. The study was composed of 5 surveys over a 1.5-yr period and included the monitoring of cleaning and disinfection procedures. Overall, a total of 212 samples were tested for the presence of L. monocytogenes, and 31% of the samples were found to be positive. Listeria monocytogenes was isolated from carcasses and product contact and noncontact sites in the evisceration and carcass classification areas of the abattoir. A total of 132 L. monocytogenes isolates were characterized by PCR-based serotyping and pulsed-field gel electrophoresis (PFGE) restriction analysis with the endonucleases ApaI and AscI. Molecular serotyping showed that L. monocytogenes isolates were of serotypes 1/2a and 1/2b. Isolates of serotype 1/2b (89.4%) were contaminating carcasses as well as environmental product contact and noncontact sites, whereas isolates of serotype 1/2a (10.6%) were recovered only from environmental product noncontact sites. A relatively low genetic diversity was found in this group of L. monocytogenes isolates from the abbatoir; only 14 different PFGE types (A1 to A14) were obtained. Nine pulsotypes belonging to serotype 1/2b (lineage I) were grouped in only one PFGE genetic cluster, whereas 5 pulsotypes belonging to serotype 1/2a (lineage II) were grouped into 4 PFGE genetic clusters. Two genetically related pulsotypes of serotype 1/2b (A1 and A2, 64.4% of the isolates) predominated and persisted in the abattoir. Our study indicated that a few strains of L. monocytogenes lineage I that were genetically very closely related might be specifically adapted to colonizing the evisceration zone of the abattoir and were predominant on carcasses over 1 yr. On the other hand, a genetically diverse group of lineage II strains were present in the abattoir environment, but never contaminated carcasses.
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Research Support, Non-U.S. Gov't |
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23 |
14
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Martínez-Suárez JV, Baquero F, Reig M, Pérez-Díaz JC. Transferable plasmid-linked chloramphenicol acetyltransferase conferring high-level resistance in Bacteroides uniformis. Antimicrob Agents Chemother 1985; 28:113-7. [PMID: 3899001 PMCID: PMC176320 DOI: 10.1128/aac.28.1.113] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Bacteroides uniformis RYC3373 resistant to 64 micrograms of chloramphenicol per ml was isolated from a peritoneal pelvic abscess of a patient not previously treated with this drug. Chloramphenicol resistance was transferable at low frequency to a suitable Bacteroides fragilis recipient. The acquisition of resistance was linked to the presence of a 39.5-kilobase plasmid (pRYC3373), which was subsequently transferred to a secondary recipient. The transfer of Cm resistance occurred by a conjugation-like process. Donor and transconjugant strains produced chloramphenicol acetyltransferase constitutively. The Km for chloramphenicol was 40 microM, and its inactivation by 5-5'-dithiobis(2-nitrobenzoic acid) suggested its similarity to the type II enterobacterial enzymes encoded by different conjugative plasmids and also to a previously described enzyme of B. fragilis F47 and F48. The specific activity and the resistance level in pRYC3373-bearing strains were more than 10-fold higher than in the case of the enzyme from B. fragilis strains F47 and F48. The genetic basis of chloramphenicol acetyltransferase synthesis in Bacteroides spp. had not been previously established.
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research-article |
40 |
22 |
15
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Polanco AM, Rodríguez-Tudela JL, Martínez-Suárez JV. Detection of pathogenic fungi in human blood by the polymerase chain reaction. Eur J Clin Microbiol Infect Dis 1995; 14:618-21. [PMID: 7588851 DOI: 10.1007/bf01690738] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The ability of the polymerase chain reaction (PCR) to detect pathogenic fungi in human blood was investigated. A DNA fragment of about 300 bp from the 18S rDNA, highly conserved in all fungi, was amplified with target DNA from 18 different species of fungi commonly isolated from clinical samples. The presence of PCR products was confirmed by hybridization with a fluorescein-labelled internal probe (21-mer). The PCR assay described is sensitive enough to detect 125 fg of purified Candida albicans DNA and 10 to 100 yeast cells per millilitre of blood.
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20 |
16
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Barroso I, Maia V, Cabrita P, Martínez-Suárez JV, Brito L. The benzalkonium chloride resistant or sensitive phenotype of Listeria monocytogenes planktonic cells did not dictate the susceptibility of its biofilm counterparts. Food Res Int 2019; 123:373-382. [PMID: 31284989 DOI: 10.1016/j.foodres.2019.05.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 04/11/2019] [Accepted: 05/03/2019] [Indexed: 12/28/2022]
Abstract
The main goal of this work was to approach food industry conditions in the comparison of the susceptibility of biofilms of Listeria monocytogenes to the biocides benzalkonium chloride (BAC) and peracetic acid (PAA). Twelve isolates of L. monocytogenes, including nine well characterized BAC resistant strains were used. Biofilms were produced on stainless steel coupons (SSC), at 11 °C (refrigeration temperature) or at 25 °C (room temperature), in culture media simulating clean (nutrient limiting) or soiled (nutrient rich) growth conditions. Neither different nutrient availability nor growth temperature showed significant effect (p > .05) on biofilm formation. PAA confirmed to be more effective than BAC in biofilm elimination. Biofilms formed under nutritional stress tended to differentiate more the response to BAC of the resistant or sensitive strains, but the resistant or sensitive phenotype of the planktonic cells did not dictate biofilm susceptibility.
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Research Support, Non-U.S. Gov't |
6 |
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17
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Jantzen MM, Navas J, de Paz M, Rodríguez B, da Silva WP, Nuñez M, Martínez-Suárez JV. Evaluation of ALOA plating medium for its suitability to recover high pressure-injured Listeria monocytogenes from ground chicken meat. Lett Appl Microbiol 2006; 43:313-7. [PMID: 16910938 DOI: 10.1111/j.1472-765x.2006.01950.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS To evaluate a chromogenic plating medium for the isolation of sublethally injured cells of Listeria monocytogenes from processed foods. METHODS AND RESULTS The inactivation of L. monocytogenes at pressures up to 400 MPa and 12 degrees C in ground chicken meat was employed to examine the recovery of high-pressure injured cells. Before and after different repair incubation periods at 30 degrees C in a nonselective broth, samples were plated onto a selective and differential agar [Agar Listeria according to Ottaviani and Agosti (ALOA)] and in the same medium supplemented with 4% sodium chloride (ALOA-S), and incubated at 37 degrees C. Sublethally injured cells were able to grow when directly plated onto the ALOA medium, without a previous repair incubation period. However, only uninjured cells grew on the ALOA-S medium. CONCLUSIONS Sublethally injured cells of L. monocytogenes can be quantified by subtracting counts on ALOA-S medium from counts on ALOA medium. SIGNIFICANCE AND IMPACT OF THE STUDY Possible applications include direct enumeration on ALOA of stressed cells of L. monocytogenes in foods with more than 100 colony forming units per gram.
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Research Support, Non-U.S. Gov't |
19 |
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18
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Ruiz-Díez B, Martínez-Suárez JV. Isolation, characterization, and antifungal susceptibility of melanin-deficient mutants of Scedosporium prolificans. Curr Microbiol 2003; 46:228-32. [PMID: 12567248 DOI: 10.1007/s00284-002-3858-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Scedosporium prolificans mutants lacking the ability to synthesize melanin were selected after ultraviolet light (UV) irradiation. UV exposure of S. prolificans conidia resulted in a high frequency of melanin-deficient (mel-) mutants. Stable and non-stable morphological variants were found in the population: reversion of the mutant phenotype was always to the wild-type phenotype. Based on their morphological differences, these variants were classified into five different groups that were phenotypically characterized. The mel- mutants plus the wild-type strain were examined for in vitro susceptibility to antifungal agents with different and/or the same mechanism of action. There was no apparent difference in minimum inhibitory concentrations when comparing the wild-type and the mel- mutants. Therefore, melanin does not appear to confer protection against the more important antifungal agents in S. prolificans.
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López V, Navas J, Martínez-Suárez JV. Low potential virulence associated with mutations in the inlA and prfA genes in Listeria monocytogenes isolated from raw retail poultry meat. J Food Prot 2013; 76:129-32. [PMID: 23317868 DOI: 10.4315/0362-028x.jfp-12-304] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Packaged raw foods can represent a potential source of Listeria monocytogenes contamination when opened at home, and listeriosis is associated with the consumption of undercooked raw foods. The aim of this study was to characterize a group of L. monocytogenes strains isolated from 56 packages of raw chicken meat from a single brand in order to determine the diversity of the strains that dominate in a particular food over time, as well as their pathogenic potential. Forty (71%) samples were found to be positive for L. monocytogenes, and three isolates per sample were subjected to PCR molecular serotyping. Subtyping of 45 isolates from different manufacturing dates (n = 40) or different molecular serotype within the same sample (n = 5) identified 11 different L. monocytogenes subtypes as defined by pulsed-field gel electrophoresis and sequencing of virulence genes actA and inlA. Two of the subtypes accounted for 51% of the isolates. About 40% of isolates (three subtypes) were found to potentially present attenuated virulence because of the presence of mutations in the prfA and inlA genes.
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Martínez-Suárez JV, Martínez JL, López de Goicoechea MJ, Pérez-Díaz JC, Baquero F, Meseguer M, Liñares J. Acquisition of antibiotic resistance plasmids in vivo by extraintestinal Salmonella spp. J Antimicrob Chemother 1987; 20:452-3. [PMID: 3680083 DOI: 10.1093/jac/20.3.452] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Case Reports |
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Ruiz-Díez B, Martínez-Suárez JV. Electrotransformation of the human pathogenic fungus Scedosporium prolificans mediated by repetitive rDNA sequences. FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY 1999; 25:275-82. [PMID: 10459582 DOI: 10.1111/j.1574-695x.1999.tb01352.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The regions encoding the 5.8S rRNA and the flanking internal transcribed spacers (ITSI and ITSII) from two isolates of the human pathogenic fungus Scedosporium prolificans and one isolate of the taxonomically related species Pseudallescheria boydii (S. apiospermum) were sequenced. The sequences of the two S. prolificans isolates were identical. However, there were minor differences between both species. Phylogenetic analysis of known fungal sequences confirmed a close relationship between S. prolificans and P. boydii. An attempt was made to transform S. prolificans by electroporation using a plasmid vector, pMLF2, bearing the Escherichia coli hygromycin B phosphotransferase gene (hph) under the control of Aspergillus nidulans promoter and terminator sequences. To increase transformation efficiency, the sequenced ribosomal cluster of S. prolificans was used to construct a new vector for homologous recombination.
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Ortiz S, López V, Garriga M, Martínez-Suárez JV. Antilisterial effect of two bioprotective cultures in a model system of Iberian chorizo fermentation. Int J Food Sci Technol 2013. [DOI: 10.1111/ijfs.12362] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Navas J, Ortiz S, López P, López V, Martínez-Suárez JV, MARTÍNEZ-SUÁREZ V. Different enrichment procedures for recovery of Listeria monocytogenes from raw chicken samples can affect the results of detection (by chromogenic plating or real-time PCR) and lineage or strain identification. J Food Prot 2007; 70:2851-4. [PMID: 18095442 DOI: 10.4315/0362-028x-70.12.2851] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study aimed to evaluate the effect of different enrichment procedures on the detection of Listeria monocytogenes in food, by a comparison of subculture onto chromogenic agar with real-time PCR. Two different culture media, the primary and secondary enrichment broths of the U.S. Food Safety and Inspection Service (FSIS) method used for PCR detection of L. monocytogenes, were compared for the primary enrichment of retail ground chicken samples. L. monocytogenes was detected after the completion of each enrichment procedure in 63% (complete FSIS procedure) and 60% (plain FSIS secondary enrichment broth incubated for 48 h) of the samples by both culture and PCR, whereas a combination of the results for the two enrichment procedures revealed 86% of the samples to be positive. Most of the samples analyzed contained a mixture of lineage I and II strains, and their ratio varied for each enrichment procedure. This mixture could have a significant effect on the result of detection of L. monocytogenes for each individual sample, explaining the increase in positive samples when the results of the two enrichment procedures were combined. The use of different isolation procedures can affect the specific samples identified as positive and the specific strains isolated.
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Comparative Study |
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Montiel R, Peirotén Á, Ortiz S, Bravo D, Gaya P, Martínez-Suárez JV, Tapiador J, Nuñez M, Medina M. Inactivation of Listeria monocytogenes during dry-cured ham processing. Int J Food Microbiol 2020; 318:108469. [DOI: 10.1016/j.ijfoodmicro.2019.108469] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 09/10/2019] [Accepted: 12/01/2019] [Indexed: 01/11/2023]
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Varsaki A, Ortiz S, Santorum P, López P, López-Alonso V, Hernández M, Abad D, Rodríguez-Grande J, Ocampo-Sosa AA, Martínez-Suárez JV. Prevalence and Population Diversity of Listeria monocytogenes Isolated from Dairy Cattle Farms in the Cantabria Region of Spain. Animals (Basel) 2022; 12:ani12182477. [PMID: 36139336 PMCID: PMC9495194 DOI: 10.3390/ani12182477] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/08/2022] [Accepted: 09/14/2022] [Indexed: 11/24/2022] Open
Abstract
Simple Summary The origin and prevalence of Listeria monocytogenes was studied in dairy cattle farms in order to examine its diversity and determine its possible persistence in manure. The utilization of manure for agricultural purposes is common in many countries. While properly treated and managed manure is an effective and safe fertilizer, foodborne illness outbreaks can occur, as many of the most prominent foodborne pathogens are carried by healthy livestock. It is, therefore, necessary to study the origin and persistence of zoonotic agents in general and of L. monocytogenes in particular, in order to avoid recirculation in farms and reduce risk for human populations. Abstract Listeria monocytogenes is an opportunistic pathogen that is widely distributed in the environment. Here we show the prevalence and transmission of L. monocytogenes in dairy farms in the Cantabria region, on the northern coast of Spain. A total of 424 samples was collected from 14 dairy farms (5 organic and 9 conventional) and 211 L. monocytogenes isolates were recovered following conventional microbiological methods. There were no statistically significant differences in antimicrobial resistance ratios between organic and conventional farms. A clonal relationship among the isolates was assessed by pulsed field gel electrophoresis (PFGE) analysis and 64 different pulsotypes were obtained. Most isolates (89%, n = 187) were classified as PCR serogroup IVb by using a multiplex PCR assay. In this case, 45 isolates of PCR serogroup IVb were whole genome-sequenced to perform a further analysis at genomic level. In silico MLST analysis showed the presence of 12 sequence types (ST), of which ST1, ST54 and ST666 were the most common. Our data indicate that the environment of cattle farms retains a high incidence of L. monocytogenes, including subtypes involved in human listeriosis reports and outbreaks. This pathogen is shed in the feces and could easily colonize dairy products, as a result of fecal contamination. Effective herd and manure management are needed in order to prevent possible outbreaks.
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