International journal of antimicrobial agents, Jan 24, 2017
Phage particles have emerged as elements with the potential to mobilize antibiotic resistance gen... more Phage particles have emerged as elements with the potential to mobilize antibiotic resistance genes (ARGs) in different environments, including the intestinal habitat. The aim of this study was to determine the occurrence of ARGs in phage particles present in fecal matter and induced from strains isolated from feces. Nine ARGs (blaTEM, blaCTX-M-1-group, blaCTX-M-9-group, blaOXA-48, qnrA, qnrS, mecA, sul1 and armA) were quantified by qPCR in the phage DNA fractions of 150 fecal samples obtained from healthy individuals. These subjects had not received antibiotic treatment or travelled abroad in the three months prior to the sample collection. On the suspicion that the detected particles originated from bacterial flora, 82 Escherichia coli and Klebsiella pneumoniae isolates possessing at least one identified ARG (blaTEM, blaCTX-M-1-group, blaCTX-M-9-group, armA, qnrA, qnrS, and sul1) were isolated and their capacity to produce phage particles carrying these ARGs after induction was ev...
International Journal of Antimicrobial Agents, 2016
Escherichia coli recovered from three hospitals in Barcelona (Spain) were studied to determine th... more Escherichia coli recovered from three hospitals in Barcelona (Spain) were studied to determine the prevalence of isolates with acquired AmpC (ac-AmpC) and/or overproduced chromosomal AmpC (c-AmpC). Mechanisms involved in blac-AmpC overexpression, blaac-AmpC and the plasmids associated with their distribution as well as the prevalence of plasmid-mediated quinolone resistance (PMQR) in AmpC-producing isolates were also determined. Isolates were selected according to their resistance phenotype. blaac-AmpC, alterations in the blac-AmpC promoter/attenuator, and PMQR genes [qnrA, qnrB, qnrS, aac(6')-Ib-cr and qepA] were characterised by PCR and sequencing. blac-AmpC expression was determined by qRT-PCR. Population structure analysis was performed using PFGE, MLST and phylogenetic group PCR. Plasmids carrying blaac-AmpC were characterised by PCR-based replicon typing and S1-PFGE. IncI1 and IncF plasmids were also analysed by plasmid MLST and replicon sequence typing, respectively. Among 21563 E. coli isolates, 240 (1.1%) overproduced AmpC β-lactamases, including 180 (75.0%) harbouring ac-AmpC (132 CMY-2 variants and 48 DHA-1) and 60 (25.0%) c-AmpC enzymes. Three mutation profiles in the blac-AmpC promoter/attenuator were associated with a 72.5-, 19.9- and 5.8-fold increased expression, respectively. Moreover, 63.3% of ac-AmpC and 43.3% of c-AmpC isolates belonged to B2, D, E or F phylogenetic groups. PMQR was found in 31% of ac-AmpC isolates [38 qnrB4, 8…
T he new coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 (severe acute respiratory syndr... more T he new coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) emerged in China in October-November 2019 (ref. 1) and by the end of March 2020 it was present in most countries of the world. The World Health Organization (WHO) declared the new disease as a pandemic on 11 March 2020. Spain suffered a severe epidemic, with the first case reported on 29 January 2020 (ref. 2), and an accumulated number of 249,659 cases by 1 July 2020, including 28,363 fatalities 3. Furthermore, a nationwide seroprevalence study showed that only one in ten cases of infection by SARS-CoV-2 were diagnosed and reported in that period 4 , suggesting that the total number of infections has been vastly underestimated. Spain ordered a series of nonpharmaceutical intervention measures, including a general lockdown on
International Journal of Antimicrobial Agents, 2007
The rapid spread of acquired metallo--lactamases (MBLs) among major Gram-negative pathogens is a... more The rapid spread of acquired metallo--lactamases (MBLs) among major Gram-negative pathogens is a matter of particular concern worldwide and primarily in Europe, one of first continents where the emergence of acquired MBLs has been reported and possibly the geographical area where the increasing diversity of these enzymes and the number of bacterial species affected are most impressive. This spread has not been paralleled by accuracy/standardisation of detection methods, completeness of epidemiological knowledge or a clear understanding of what MBL production entails in terms of clinical impact, hospital infection control and antimicrobial chemotherapy. A number of European experts in the field met to review the current knowledge on this phenomenon, to point out open issues and to reinforce and relate to one another the existing activities set forth by research institutes, scientific societies and European Union-driven networks.
The aim of this study was to characterize the different inhibitor-resistant TEM b-lactamases, ext... more The aim of this study was to characterize the different inhibitor-resistant TEM b-lactamases, extended-spectrum b-lactamases (ESBLs) and plasmid-mediated AmpC b-lactamases implicated in b-lactam resistance in Proteus mirabilis, which has increased over recent years. Methods: From February 2000 to December 2005, 1423 clinical isolates of P. mirabilis were collected. The AmpC phenotype was checked by means of a double-disc synergy test using cloxacillin as an inhibitor of AmpC enzymes. The production of ESBL was assessed by the double-disc synergy method and by Etest ESBL. Analytical isoelectric focusing, determination of kinetic constants, conjugation, PCR and a sequencing strategy were used to characterize the enzymes. The possible relationships between isolates were analysed by PFGE. Results and conclusions: Twenty-five of 1423 isolates were found to display intermediate or full resistance to co-amoxiclav, cefotaxime or ceftazidime. Seventeen isolates had reduced susceptibility to co-amoxiclav; of these, seven produced TEM-110, eight produced the new TEM-159, one the new TEM-160 and one TEM-1. Five isolates producing TEM-110, TEM-159 or TEM-160 enzymes shared the same PFGE profile. Three isolates produced an ESBL, CTX-M-1, CTX-M-32 and the new variant, VEB-4. Finally, five isolates with an AmpC phenotype produced CMY-2, two with the same PFGE profile. Our data emphasize the diversity of b-lactamases found in this species.
The ability of the new VITEK 2 Neisseria-Haemophilus card (bioMérieux) for the identification of ... more The ability of the new VITEK 2 Neisseria-Haemophilus card (bioMérieux) for the identification of Neisseria, Haemophilus and other fastidious Gram-negative organisms was compared with 16S rRNA gene sequencing and others reference methods, in a clinical microbiology laboratory. The VITEK 2 NH card correctly identified 100 isolates (95%) of 105 isolates. Four isolates were misidentified (1 Campylobacter coli, 1 Campylobacter jejuni, 1 Neisseria meningitidis and 1 Haemophilus influenzae) and one C. coli was unidentified. With its extended database and results available within 6 hours, this card could be considered a useful tool for routine use in clinical microbiology laboratory.
Forty-eight Streptococcus pneumoniae isolates recovered from sputum samples from 26 cystic fibros... more Forty-eight Streptococcus pneumoniae isolates recovered from sputum samples from 26 cystic fibrosis (CF) patients attending our CF unit (1995 to 2003) were studied. Mean yearly incidence of isolation was 5.5%, and all were strains recovered from young patients ( 12 years). The ...
In this study, the plasmid content of clinical and commensal strains was analysed and compared. T... more In this study, the plasmid content of clinical and commensal strains was analysed and compared. The replicon profile was similar in both, except for L, M, A/C and N (detected only in clinical strains) and HI1 (only in commensal strains). Although I1 and F were the most frequent replicons, only IncI1 ST12 was associated with blaCMY-2 in both populations. In contrast, the widespread resistant IncF plasmids were not linked to a single epidemic plasmid.
Ascitic neutrophils from cirrhotic patients with spontaneous bacterial peritonitis (SBP) exhibit ... more Ascitic neutrophils from cirrhotic patients with spontaneous bacterial peritonitis (SBP) exhibit an impaired oxidative burst that could facilitate bacterial infection. However, the influence of the cell-free ascitic fluid of these patients on neutrophil function has not been investigated. To analyze this influence, we determined the ascitic levels of cytokines, resistin, and lactoferrin and their association with neutrophil function, disease severity score, and SBP resolution. We analyzed NETosis induction by microscopy and oxidative burst by the flow cytometry of healthy neutrophils cultured in ascitic fluid from cirrhotic patients with sterile ascites (SA) and with SBP before and after antibiotic treatment. Resistin, IL-6, IL-1 receptor antagonist, IL-1β, and lactoferrin levels were measured in ascitic fluids and supernatants of cultured neutrophils and PBMCs by ELISA. Upon stimulation, healthy neutrophils cultured in SBP ascitic fluid produced lower NETosis and oxidative burst th...
Microbial drug resistance (Larchmont, N.Y.), Jan 30, 2017
During a Spanish surveillance study, a natural variant of a CMY-type β-lactamase related to CMY-2... more During a Spanish surveillance study, a natural variant of a CMY-type β-lactamase related to CMY-2 with a GluLeu(217-218) insertion in the Ω-loop (designated CMY-54) was found to increase the minimum inhibitory concentractions to β-lactams in a clinical strain of Escherichia coli. The aim of this study was to characterize CMY-54 by genetic, microbiological, and biochemical analysis. The blaCMY-54 gene is encoded by a plasmid of around 100 kb that hybridizes with K and FIB probes. The genetic context of blaCMY-54 and blaCMY-2 genes was found to be very similar. E. coli expressing CMY-54 under isogenic conditions showed a clear fourfold to eightfold increase in MICs to penicillins, cefotaxime, ceftazidime, and aztreonam compared with CMY-2. The catalytic efficiencies of pure CMY-2 and CMY-54 proteins correlated with their microbiological parameters. CMY-2 protein was more resistant to thermal denaturation than CMY-54, indicating than the Ω-loop of CMY-54 may be wider and more relaxed a...
Microbial drug resistance (Larchmont, N.Y.), Jan 26, 2017
This study describes the molecular characterization of an NDM-7 carbapenemase-producing Escherich... more This study describes the molecular characterization of an NDM-7 carbapenemase-producing Escherichia coli strain Ec188, recovered from a rectal swab of a male patient who had travelled to Pakistan before his hospitalization at the Hospital del Mar in Barcelona, Spain. The Ec188 isolate, assigned to a new multilocus sequence type ST679, was resistant to all beta-lactams, aminoglycosides (gentamicin, tobramycin, and with reduced susceptibility to amikacin), and ciprofloxacin. The blaNDM-7 gene was located on a 50 kb IncX4 plasmid (pEc188-NDM7), both in the original and transconjugant strains. In addition, blaCTX-M-15 was located on a 150 kb IncFIA plasmid and blaCMY-2 on a 95 kb undetermined plasmid type, only in the wild-type strain. The immediate genetic surroundings of blaNDM-7 included the bleo, trpf, and dsbC genes, and it was flanked by the insertion sequences IS26 and ISAba125, which appeared interrupted by IS5. The res and parA genes were found in the same orientation downstrea...
Bacteriophages, viruses that infect bacteria, have re-emerged as powerful regulators of bacterial... more Bacteriophages, viruses that infect bacteria, have re-emerged as powerful regulators of bacterial populations in natural ecosystems. Phages invade the human body, just as they do other natural environments, to such an extent that they are the most numerous group in the human virome. This was only revealed in recent metagenomic studies, despite the fact that the presence of phages in the human body was reported decades ago. The influence of the presence of phages in humans has yet to be evaluated; but as in marine environments, a clear role in the regulation of bacterial populations could be envisaged, that might have an impact on human health. Moreover, phages are excellent vehicles of genetic transfer, and they contribute to the evolution of bacterial cells in the human body by spreading and acquiring DNA horizontally. The abundance of phages in the human body does not pass unnoticed and the immune system reacts to them, although it is not clear to what extent. Finally, the presenc...
Microbial drug resistance (Larchmont, N.Y.), Jan 17, 2017
Proteus mirabilis is the second most common cause of urinary tract infections and is also an impo... more Proteus mirabilis is the second most common cause of urinary tract infections and is also an important cause of nosocomial infections. TEM-type and CTX-M-type extended-spectrum β-lactamases (ESBLs) are the most widely distributed in this bacterial species, but minor ESBLs such as the VEB-type have also been identified. The aim of this study was to analyze the genetic environment of the blaVEB-4 gene found in a P. mirabilis clinical isolate recovered in Spain. P. mirabilis N2231 showed resistance to penicillins, cephalosporins, and aminoglycosides, remaining susceptible to imipenem, cefoxitin, β-lactamases inhibitors, and quinolones. Southern blot analysis revealed that blaVEB-4 was located in the chromosome. Analysis of the blaVEB-4 genetic context revealed a 15 kb segment 98% identical to the multidrug resistance (MDR) region of a Salmonella genomic island 1 (SGI1), which included a class 1 integron belonging to the In104 family, previously described in blaVEB-6-producing P. mirabi...
Bacillus toyonensis strain BCT-7112(T) (NCIMB 14858(T)) has been widely used as an additive in an... more Bacillus toyonensis strain BCT-7112(T) (NCIMB 14858(T)) has been widely used as an additive in animal nutrition for more than 30 years without reports of adverse toxigenic effects. However, this strain is resistant to chloramphenicol and tetracycline and it is generally considered inadvisable to introduce into the food chain resistance determinants capable of being transferred to other bacterial strains, thereby adding to the pool of such determinants in the gastro-enteric systems of livestock species. We therefore characterized the resistance phenotypes of this strain and its close relatives to determine whether they were of recent origin, and therefore likely to be transmissible. To this end we identified the genes responsible for chloramphenicol (catQ) and tetracycline (tetM) resistance and confirmed the presence of homologs in other members of the B. toyonensis taxonomic unit. Unexpectedly, closely related strains encoding these genes did not exhibit chloramphenicol and tetracyc...
Trypanosoma cruzi, the causative agent of Chagas disease, is divided into six Discrete Typing Uni... more Trypanosoma cruzi, the causative agent of Chagas disease, is divided into six Discrete Typing Units (DTUs): TcI-TcVI. We aimed to identify T. cruzi DTUs in Latin-American migrants in the Barcelona area (Spain) and to assess different molecular typing approaches for the characterization of T. cruzi genotypes. Seventy-five peripheral blood samples were analyzed by two real-time PCR methods (qPCR) based on satellite DNA (SatDNA) and kinetoplastid DNA (kDNA). The 20 samples testing positive in both methods, all belonging to Bolivian individuals, were submitted to DTU characterization using two PCR-based flowcharts: multiplex qPCR using TaqMan probes (MTq-PCR), and conventional PCR. These samples were also studied by sequencing the SatDNA and classified as type I (TcI/III), type II (TcII/IV) and type I/II hybrid (TcV/VI). Ten out of the 20 samples gave positive results in the flowcharts: TcV (5 samples), TcII/V/VI (3) and mixed infections by TcV plus TcII (1) and TcV plus TcII/VI (1). By...
Enfermedades Infecciosas y Microbiología Clínica, 2016
Antimicrobial resistance in Enterobacteriaceae is increasing worldwide and is making treating inf... more Antimicrobial resistance in Enterobacteriaceae is increasing worldwide and is making treating infections caused by multidrug-resistant Enterobacteriaceae a challenge. The use of β-lactam agents is compromised by microorganisms harboring extended-spectrum β-lactamases (ESBLs) and other mechanisms of resistance. Avibactam is a non β-lactam agent that inhibits clinically relevant β-lactamases, such as ESBL and AmpC. The ceftazidime-avibactam combination (CAZ-AVI) was recently approved for use in certain complicated infections, and may provide a therapeutic alternative for infections caused by these microorganisms. The in vitro activity of CAZ and CAZ-AVI (AVI at a fixed concentration of 4mg/L) was tested against 250 clinical isolates of Enterobacteriaceae using broth microdilution. EUCAST breakpoint criteria were used for CAZ, and FDA criteria for CAZ-AVI. Clinical isolates included bacteria producing extended-spectrum β-lactamases (ESBLs) and acquired AmpC β-lactamases (AACBLs). Porin loss in Klebsiella pneumoniae was also evaluated. The combination of AVI with CAZ displayed excellent activity against clinical isolates of ESBL-producing Escherichia coli and Klebsiella pneumoniae, rendering all the ceftazidime-resistant isolates susceptible to ceftazidime. CAZ-AVI retained activity against porin-deficient isolates of K. pneumoniae producing ESBLs, AACBLs, or both, although MIC values were higher compared to porin-expressing isolates. CAZ-AVI rendered all the ceftazidime-resistant AACBL-producing Enterobacteriaceae tested susceptible to ceftazidime. CAZ-AVI showed potent in vitro activity against clinical isolates of Enterobacteriaceae producing ESBLs and/or AACBLs, including K. pneumoniae with loss of porins.
Bacteriophages are viruses that infect bacteria, and they are found everywhere their bacterial ho... more Bacteriophages are viruses that infect bacteria, and they are found everywhere their bacterial hosts are present, including the human body. To explore the presence of phages in clinical samples, we assessed 65 clinical samples (blood, ascitic fluid, urine, cerebrospinal fluid, and serum). Infectious tailed phages were detected in >45% of ascitic fluid and urine samples. Three examples of phage interference with bacterial isolation were observed. Phages prevented the confluent bacterial growth required for an antibiogram assay when the inoculum was taken from an agar plate containing lysis plaques, but not when taken from a single colony in a phage-free area. In addition, bacteria were isolated directly from ascitic fluid, but not after liquid enrichment culture of the same samples, since phage propagation lysed the bacteria. Lastly, Gram-negative bacilli observed in a urine sample did not grow on agar plates due to the high densities of infectious phages in the sample.
Enfermedades Infecciosas Y Microbiologia Clinica, Feb 1, 1996
To study the emergence of amoxicilline/clavulanate resistance in Salmonella and Shigella. We have... more To study the emergence of amoxicilline/clavulanate resistance in Salmonella and Shigella. We have studied 118 strains of Salmonella enterica and 11 strains of Shigella flexneri isolated in our laboratory along 1993. The MICs values for amoxicilline/clavulanate were determined by the E-Test method and confirmed by the standard agar dilution method. We have observed that 6% (7 out of 118 strains) of Salmonella enterica and 42% (5 out of 11 strains) of Shigella flexneri isolates exhibited an intermediate susceptibility or were resistant to amoxicilline/clavulanate with MICs values ranging between 16 mg/l and 32 mg/l. Along 1993 we have detected the emergence of an amoxicilline/clavulanate resistance in salmonellae and shigellae strains. To our knowledge this fact has not been published up to now (Medline, 1990-October 1994). We don't know the clinical importance of this fact.
International journal of antimicrobial agents, Jan 24, 2017
Phage particles have emerged as elements with the potential to mobilize antibiotic resistance gen... more Phage particles have emerged as elements with the potential to mobilize antibiotic resistance genes (ARGs) in different environments, including the intestinal habitat. The aim of this study was to determine the occurrence of ARGs in phage particles present in fecal matter and induced from strains isolated from feces. Nine ARGs (blaTEM, blaCTX-M-1-group, blaCTX-M-9-group, blaOXA-48, qnrA, qnrS, mecA, sul1 and armA) were quantified by qPCR in the phage DNA fractions of 150 fecal samples obtained from healthy individuals. These subjects had not received antibiotic treatment or travelled abroad in the three months prior to the sample collection. On the suspicion that the detected particles originated from bacterial flora, 82 Escherichia coli and Klebsiella pneumoniae isolates possessing at least one identified ARG (blaTEM, blaCTX-M-1-group, blaCTX-M-9-group, armA, qnrA, qnrS, and sul1) were isolated and their capacity to produce phage particles carrying these ARGs after induction was ev...
International Journal of Antimicrobial Agents, 2016
Escherichia coli recovered from three hospitals in Barcelona (Spain) were studied to determine th... more Escherichia coli recovered from three hospitals in Barcelona (Spain) were studied to determine the prevalence of isolates with acquired AmpC (ac-AmpC) and/or overproduced chromosomal AmpC (c-AmpC). Mechanisms involved in blac-AmpC overexpression, blaac-AmpC and the plasmids associated with their distribution as well as the prevalence of plasmid-mediated quinolone resistance (PMQR) in AmpC-producing isolates were also determined. Isolates were selected according to their resistance phenotype. blaac-AmpC, alterations in the blac-AmpC promoter/attenuator, and PMQR genes [qnrA, qnrB, qnrS, aac(6')-Ib-cr and qepA] were characterised by PCR and sequencing. blac-AmpC expression was determined by qRT-PCR. Population structure analysis was performed using PFGE, MLST and phylogenetic group PCR. Plasmids carrying blaac-AmpC were characterised by PCR-based replicon typing and S1-PFGE. IncI1 and IncF plasmids were also analysed by plasmid MLST and replicon sequence typing, respectively. Among 21563 E. coli isolates, 240 (1.1%) overproduced AmpC β-lactamases, including 180 (75.0%) harbouring ac-AmpC (132 CMY-2 variants and 48 DHA-1) and 60 (25.0%) c-AmpC enzymes. Three mutation profiles in the blac-AmpC promoter/attenuator were associated with a 72.5-, 19.9- and 5.8-fold increased expression, respectively. Moreover, 63.3% of ac-AmpC and 43.3% of c-AmpC isolates belonged to B2, D, E or F phylogenetic groups. PMQR was found in 31% of ac-AmpC isolates [38 qnrB4, 8…
T he new coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 (severe acute respiratory syndr... more T he new coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) emerged in China in October-November 2019 (ref. 1) and by the end of March 2020 it was present in most countries of the world. The World Health Organization (WHO) declared the new disease as a pandemic on 11 March 2020. Spain suffered a severe epidemic, with the first case reported on 29 January 2020 (ref. 2), and an accumulated number of 249,659 cases by 1 July 2020, including 28,363 fatalities 3. Furthermore, a nationwide seroprevalence study showed that only one in ten cases of infection by SARS-CoV-2 were diagnosed and reported in that period 4 , suggesting that the total number of infections has been vastly underestimated. Spain ordered a series of nonpharmaceutical intervention measures, including a general lockdown on
International Journal of Antimicrobial Agents, 2007
The rapid spread of acquired metallo--lactamases (MBLs) among major Gram-negative pathogens is a... more The rapid spread of acquired metallo--lactamases (MBLs) among major Gram-negative pathogens is a matter of particular concern worldwide and primarily in Europe, one of first continents where the emergence of acquired MBLs has been reported and possibly the geographical area where the increasing diversity of these enzymes and the number of bacterial species affected are most impressive. This spread has not been paralleled by accuracy/standardisation of detection methods, completeness of epidemiological knowledge or a clear understanding of what MBL production entails in terms of clinical impact, hospital infection control and antimicrobial chemotherapy. A number of European experts in the field met to review the current knowledge on this phenomenon, to point out open issues and to reinforce and relate to one another the existing activities set forth by research institutes, scientific societies and European Union-driven networks.
The aim of this study was to characterize the different inhibitor-resistant TEM b-lactamases, ext... more The aim of this study was to characterize the different inhibitor-resistant TEM b-lactamases, extended-spectrum b-lactamases (ESBLs) and plasmid-mediated AmpC b-lactamases implicated in b-lactam resistance in Proteus mirabilis, which has increased over recent years. Methods: From February 2000 to December 2005, 1423 clinical isolates of P. mirabilis were collected. The AmpC phenotype was checked by means of a double-disc synergy test using cloxacillin as an inhibitor of AmpC enzymes. The production of ESBL was assessed by the double-disc synergy method and by Etest ESBL. Analytical isoelectric focusing, determination of kinetic constants, conjugation, PCR and a sequencing strategy were used to characterize the enzymes. The possible relationships between isolates were analysed by PFGE. Results and conclusions: Twenty-five of 1423 isolates were found to display intermediate or full resistance to co-amoxiclav, cefotaxime or ceftazidime. Seventeen isolates had reduced susceptibility to co-amoxiclav; of these, seven produced TEM-110, eight produced the new TEM-159, one the new TEM-160 and one TEM-1. Five isolates producing TEM-110, TEM-159 or TEM-160 enzymes shared the same PFGE profile. Three isolates produced an ESBL, CTX-M-1, CTX-M-32 and the new variant, VEB-4. Finally, five isolates with an AmpC phenotype produced CMY-2, two with the same PFGE profile. Our data emphasize the diversity of b-lactamases found in this species.
The ability of the new VITEK 2 Neisseria-Haemophilus card (bioMérieux) for the identification of ... more The ability of the new VITEK 2 Neisseria-Haemophilus card (bioMérieux) for the identification of Neisseria, Haemophilus and other fastidious Gram-negative organisms was compared with 16S rRNA gene sequencing and others reference methods, in a clinical microbiology laboratory. The VITEK 2 NH card correctly identified 100 isolates (95%) of 105 isolates. Four isolates were misidentified (1 Campylobacter coli, 1 Campylobacter jejuni, 1 Neisseria meningitidis and 1 Haemophilus influenzae) and one C. coli was unidentified. With its extended database and results available within 6 hours, this card could be considered a useful tool for routine use in clinical microbiology laboratory.
Forty-eight Streptococcus pneumoniae isolates recovered from sputum samples from 26 cystic fibros... more Forty-eight Streptococcus pneumoniae isolates recovered from sputum samples from 26 cystic fibrosis (CF) patients attending our CF unit (1995 to 2003) were studied. Mean yearly incidence of isolation was 5.5%, and all were strains recovered from young patients ( 12 years). The ...
In this study, the plasmid content of clinical and commensal strains was analysed and compared. T... more In this study, the plasmid content of clinical and commensal strains was analysed and compared. The replicon profile was similar in both, except for L, M, A/C and N (detected only in clinical strains) and HI1 (only in commensal strains). Although I1 and F were the most frequent replicons, only IncI1 ST12 was associated with blaCMY-2 in both populations. In contrast, the widespread resistant IncF plasmids were not linked to a single epidemic plasmid.
Ascitic neutrophils from cirrhotic patients with spontaneous bacterial peritonitis (SBP) exhibit ... more Ascitic neutrophils from cirrhotic patients with spontaneous bacterial peritonitis (SBP) exhibit an impaired oxidative burst that could facilitate bacterial infection. However, the influence of the cell-free ascitic fluid of these patients on neutrophil function has not been investigated. To analyze this influence, we determined the ascitic levels of cytokines, resistin, and lactoferrin and their association with neutrophil function, disease severity score, and SBP resolution. We analyzed NETosis induction by microscopy and oxidative burst by the flow cytometry of healthy neutrophils cultured in ascitic fluid from cirrhotic patients with sterile ascites (SA) and with SBP before and after antibiotic treatment. Resistin, IL-6, IL-1 receptor antagonist, IL-1β, and lactoferrin levels were measured in ascitic fluids and supernatants of cultured neutrophils and PBMCs by ELISA. Upon stimulation, healthy neutrophils cultured in SBP ascitic fluid produced lower NETosis and oxidative burst th...
Microbial drug resistance (Larchmont, N.Y.), Jan 30, 2017
During a Spanish surveillance study, a natural variant of a CMY-type β-lactamase related to CMY-2... more During a Spanish surveillance study, a natural variant of a CMY-type β-lactamase related to CMY-2 with a GluLeu(217-218) insertion in the Ω-loop (designated CMY-54) was found to increase the minimum inhibitory concentractions to β-lactams in a clinical strain of Escherichia coli. The aim of this study was to characterize CMY-54 by genetic, microbiological, and biochemical analysis. The blaCMY-54 gene is encoded by a plasmid of around 100 kb that hybridizes with K and FIB probes. The genetic context of blaCMY-54 and blaCMY-2 genes was found to be very similar. E. coli expressing CMY-54 under isogenic conditions showed a clear fourfold to eightfold increase in MICs to penicillins, cefotaxime, ceftazidime, and aztreonam compared with CMY-2. The catalytic efficiencies of pure CMY-2 and CMY-54 proteins correlated with their microbiological parameters. CMY-2 protein was more resistant to thermal denaturation than CMY-54, indicating than the Ω-loop of CMY-54 may be wider and more relaxed a...
Microbial drug resistance (Larchmont, N.Y.), Jan 26, 2017
This study describes the molecular characterization of an NDM-7 carbapenemase-producing Escherich... more This study describes the molecular characterization of an NDM-7 carbapenemase-producing Escherichia coli strain Ec188, recovered from a rectal swab of a male patient who had travelled to Pakistan before his hospitalization at the Hospital del Mar in Barcelona, Spain. The Ec188 isolate, assigned to a new multilocus sequence type ST679, was resistant to all beta-lactams, aminoglycosides (gentamicin, tobramycin, and with reduced susceptibility to amikacin), and ciprofloxacin. The blaNDM-7 gene was located on a 50 kb IncX4 plasmid (pEc188-NDM7), both in the original and transconjugant strains. In addition, blaCTX-M-15 was located on a 150 kb IncFIA plasmid and blaCMY-2 on a 95 kb undetermined plasmid type, only in the wild-type strain. The immediate genetic surroundings of blaNDM-7 included the bleo, trpf, and dsbC genes, and it was flanked by the insertion sequences IS26 and ISAba125, which appeared interrupted by IS5. The res and parA genes were found in the same orientation downstrea...
Bacteriophages, viruses that infect bacteria, have re-emerged as powerful regulators of bacterial... more Bacteriophages, viruses that infect bacteria, have re-emerged as powerful regulators of bacterial populations in natural ecosystems. Phages invade the human body, just as they do other natural environments, to such an extent that they are the most numerous group in the human virome. This was only revealed in recent metagenomic studies, despite the fact that the presence of phages in the human body was reported decades ago. The influence of the presence of phages in humans has yet to be evaluated; but as in marine environments, a clear role in the regulation of bacterial populations could be envisaged, that might have an impact on human health. Moreover, phages are excellent vehicles of genetic transfer, and they contribute to the evolution of bacterial cells in the human body by spreading and acquiring DNA horizontally. The abundance of phages in the human body does not pass unnoticed and the immune system reacts to them, although it is not clear to what extent. Finally, the presenc...
Microbial drug resistance (Larchmont, N.Y.), Jan 17, 2017
Proteus mirabilis is the second most common cause of urinary tract infections and is also an impo... more Proteus mirabilis is the second most common cause of urinary tract infections and is also an important cause of nosocomial infections. TEM-type and CTX-M-type extended-spectrum β-lactamases (ESBLs) are the most widely distributed in this bacterial species, but minor ESBLs such as the VEB-type have also been identified. The aim of this study was to analyze the genetic environment of the blaVEB-4 gene found in a P. mirabilis clinical isolate recovered in Spain. P. mirabilis N2231 showed resistance to penicillins, cephalosporins, and aminoglycosides, remaining susceptible to imipenem, cefoxitin, β-lactamases inhibitors, and quinolones. Southern blot analysis revealed that blaVEB-4 was located in the chromosome. Analysis of the blaVEB-4 genetic context revealed a 15 kb segment 98% identical to the multidrug resistance (MDR) region of a Salmonella genomic island 1 (SGI1), which included a class 1 integron belonging to the In104 family, previously described in blaVEB-6-producing P. mirabi...
Bacillus toyonensis strain BCT-7112(T) (NCIMB 14858(T)) has been widely used as an additive in an... more Bacillus toyonensis strain BCT-7112(T) (NCIMB 14858(T)) has been widely used as an additive in animal nutrition for more than 30 years without reports of adverse toxigenic effects. However, this strain is resistant to chloramphenicol and tetracycline and it is generally considered inadvisable to introduce into the food chain resistance determinants capable of being transferred to other bacterial strains, thereby adding to the pool of such determinants in the gastro-enteric systems of livestock species. We therefore characterized the resistance phenotypes of this strain and its close relatives to determine whether they were of recent origin, and therefore likely to be transmissible. To this end we identified the genes responsible for chloramphenicol (catQ) and tetracycline (tetM) resistance and confirmed the presence of homologs in other members of the B. toyonensis taxonomic unit. Unexpectedly, closely related strains encoding these genes did not exhibit chloramphenicol and tetracyc...
Trypanosoma cruzi, the causative agent of Chagas disease, is divided into six Discrete Typing Uni... more Trypanosoma cruzi, the causative agent of Chagas disease, is divided into six Discrete Typing Units (DTUs): TcI-TcVI. We aimed to identify T. cruzi DTUs in Latin-American migrants in the Barcelona area (Spain) and to assess different molecular typing approaches for the characterization of T. cruzi genotypes. Seventy-five peripheral blood samples were analyzed by two real-time PCR methods (qPCR) based on satellite DNA (SatDNA) and kinetoplastid DNA (kDNA). The 20 samples testing positive in both methods, all belonging to Bolivian individuals, were submitted to DTU characterization using two PCR-based flowcharts: multiplex qPCR using TaqMan probes (MTq-PCR), and conventional PCR. These samples were also studied by sequencing the SatDNA and classified as type I (TcI/III), type II (TcII/IV) and type I/II hybrid (TcV/VI). Ten out of the 20 samples gave positive results in the flowcharts: TcV (5 samples), TcII/V/VI (3) and mixed infections by TcV plus TcII (1) and TcV plus TcII/VI (1). By...
Enfermedades Infecciosas y Microbiología Clínica, 2016
Antimicrobial resistance in Enterobacteriaceae is increasing worldwide and is making treating inf... more Antimicrobial resistance in Enterobacteriaceae is increasing worldwide and is making treating infections caused by multidrug-resistant Enterobacteriaceae a challenge. The use of β-lactam agents is compromised by microorganisms harboring extended-spectrum β-lactamases (ESBLs) and other mechanisms of resistance. Avibactam is a non β-lactam agent that inhibits clinically relevant β-lactamases, such as ESBL and AmpC. The ceftazidime-avibactam combination (CAZ-AVI) was recently approved for use in certain complicated infections, and may provide a therapeutic alternative for infections caused by these microorganisms. The in vitro activity of CAZ and CAZ-AVI (AVI at a fixed concentration of 4mg/L) was tested against 250 clinical isolates of Enterobacteriaceae using broth microdilution. EUCAST breakpoint criteria were used for CAZ, and FDA criteria for CAZ-AVI. Clinical isolates included bacteria producing extended-spectrum β-lactamases (ESBLs) and acquired AmpC β-lactamases (AACBLs). Porin loss in Klebsiella pneumoniae was also evaluated. The combination of AVI with CAZ displayed excellent activity against clinical isolates of ESBL-producing Escherichia coli and Klebsiella pneumoniae, rendering all the ceftazidime-resistant isolates susceptible to ceftazidime. CAZ-AVI retained activity against porin-deficient isolates of K. pneumoniae producing ESBLs, AACBLs, or both, although MIC values were higher compared to porin-expressing isolates. CAZ-AVI rendered all the ceftazidime-resistant AACBL-producing Enterobacteriaceae tested susceptible to ceftazidime. CAZ-AVI showed potent in vitro activity against clinical isolates of Enterobacteriaceae producing ESBLs and/or AACBLs, including K. pneumoniae with loss of porins.
Bacteriophages are viruses that infect bacteria, and they are found everywhere their bacterial ho... more Bacteriophages are viruses that infect bacteria, and they are found everywhere their bacterial hosts are present, including the human body. To explore the presence of phages in clinical samples, we assessed 65 clinical samples (blood, ascitic fluid, urine, cerebrospinal fluid, and serum). Infectious tailed phages were detected in >45% of ascitic fluid and urine samples. Three examples of phage interference with bacterial isolation were observed. Phages prevented the confluent bacterial growth required for an antibiogram assay when the inoculum was taken from an agar plate containing lysis plaques, but not when taken from a single colony in a phage-free area. In addition, bacteria were isolated directly from ascitic fluid, but not after liquid enrichment culture of the same samples, since phage propagation lysed the bacteria. Lastly, Gram-negative bacilli observed in a urine sample did not grow on agar plates due to the high densities of infectious phages in the sample.
Enfermedades Infecciosas Y Microbiologia Clinica, Feb 1, 1996
To study the emergence of amoxicilline/clavulanate resistance in Salmonella and Shigella. We have... more To study the emergence of amoxicilline/clavulanate resistance in Salmonella and Shigella. We have studied 118 strains of Salmonella enterica and 11 strains of Shigella flexneri isolated in our laboratory along 1993. The MICs values for amoxicilline/clavulanate were determined by the E-Test method and confirmed by the standard agar dilution method. We have observed that 6% (7 out of 118 strains) of Salmonella enterica and 42% (5 out of 11 strains) of Shigella flexneri isolates exhibited an intermediate susceptibility or were resistant to amoxicilline/clavulanate with MICs values ranging between 16 mg/l and 32 mg/l. Along 1993 we have detected the emergence of an amoxicilline/clavulanate resistance in salmonellae and shigellae strains. To our knowledge this fact has not been published up to now (Medline, 1990-October 1994). We don't know the clinical importance of this fact.
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Papers by Ferran Navarro