Papers by Carlos Gutiérrez
mBio, 2016
The Gram-positive bacterium Lactococcus lactis, used for the production of cheeses and other ferm... more The Gram-positive bacterium Lactococcus lactis, used for the production of cheeses and other fermented dairy products, falls victim frequently to fortuitous infection by tailed phages. The accompanying risk of dairy fermentation failures in industrial facilities has prompted in-depth investigations of these phages. Lactococcal phage Tuc2009 possesses extensive genomic homology to phage TP901-1. However, striking differences in the baseplate-encoding genes stimulated our interest in solving the structure of this host's adhesion device. We report here the X-ray structures of phage Tuc2009 receptor binding protein (RBP) and of a "tripod" assembly of three baseplate components, BppU, BppA, and BppL (the RBP). These structures made it possible to generate a realistic atomic model of the complete Tuc2009 baseplate that consists of an 84-protein complex: 18 BppU, 12 BppA, and 54 BppL proteins. The RBP head domain possesses a different fold than those of phages p2, TP901-1, an...
Eurosurveillance, 2015
In 2012, a new betacoronavirus, Middle East respiratory syndrome coronavirus (MERS-CoV), was iden... more In 2012, a new betacoronavirus, Middle East respiratory syndrome coronavirus (MERS-CoV), was identified in humans. Several studies confirmed dromedary camels to be a potential reservoir and a source for human infection. Camels located on the Canary Islands were included in those studies and ca 10% of them were positive for MERS-CoV-specific antibodies. However, these findings could not be correctly interpreted because epidemiological information was not provided. Thus, further investigations were necessary to clarify these results. A total of 170 camels were investigated in this survey, of which seven (4.1%) were seropositive by ELISA. Epidemiological information revealed that all seropositive camels had been imported from Africa 20 or more years prior. We conclude that seropositive camels had contact with MERS-CoV in Africa and that there is no shedding of the virus among camels or people around the farms on the Canary Islands. However, the presence of antibodies in the camel herds should be monitored.
Methods Mol.Biol., 2012
Immunizing a camelid (camels and llamas) with soluble, properly folded proteins raises an affinit... more Immunizing a camelid (camels and llamas) with soluble, properly folded proteins raises an affinity-matured immune response in the unique camelid heavy-chain only antibodies (HCAbs). The peripheral blood lymphocytes of the immunized animal are used to clone the antigen-binding antibody fragment from the HCAbs in a phage display vector. A representative aliquot of the library of these antigen-binding fragments is used to retrieve single domain antigen-specific binders by successive rounds of panning. These single domain antibody fragments are cloned in tandem to generate manifold constructs (bivalent, biparatopic or bispecific constructs) to increase their functional affinity, to increase specificity, or to connect two independent antigen molecules.
Veterinary …, 2010
Trypanosoma evansi was diagnosed for the first time in camels in the Canary Islands in 1997. Seve... more Trypanosoma evansi was diagnosed for the first time in camels in the Canary Islands in 1997. Several sanitary measures including treatment of infected animals were taken; however, nowadays a little area is still infected. In order to determine possible reservoirs 138 wild rodents were trapped, 64 of them in the infected farms and the remaining 74 in other areas. The captured species were Rattus rattus (24), Rattus norvegicus (69) and Mus musculus domesticus (45). Serological (CATT/T. evansi), parasitological (micro-Hematocrit Centrifugation technique and stained smears) and molecular (PCR) methods for T. evansi and T. lewisi were used as diagnostic methods. None of the examined rodents was positive for T. evansi; 18, however, showed motile trypanosomes at micro-Hematocrit Centrifugation technique and resulted positive for T. lewisi by PCR. The results would suggest that the studied rodent species would not play a relevant role in the epidemiology of T. evansi infection in Canaries.
Veterinary …, 2006
Ocular lesions associated with Trypanosoma spp. infection have been described in man and many ani... more Ocular lesions associated with Trypanosoma spp. infection have been described in man and many animal species. However, loss of vision has not been demonstrated in humans presenting Chagas disease or in animals affected by different trypanosome species. In order to assess the possible ocular disorders caused by Trypanosoma evansi infection, six goats were inoculated with 1 Â 10 5 T. evansi and maintained for 12 months and four goats were used as control. The inoculated animals became positive at serological and parasitological tests at 1-month post-inoculation and showed a subclinical course of the disease. Unilateral superficial corneal ulceration and retinochoroiditis were observed in two inoculated animals. Data from ocular neurologic examination and electroretinography showed no significant differences between inoculated and non-inoculated goats. It could be concluded that Trypanosoma evansi can produce ocular lesion but without apparent loss of vision in goats. #
isocard.org
Questo studio ha esaminato la presenza, i fattori di virulenza e la resistenza agli antibiotici p... more Questo studio ha esaminato la presenza, i fattori di virulenza e la resistenza agli antibiotici più comunemente utilizzati in terapia dei ceppi di Enterococcus spp. isolati dalle feci di cammelli. Centosettantatre ceppi di Enterococcus spp. sono stati isolati e identificati mediante reazione a catena della polimerasi (PCR). La resistenza nei confronti di 11 antibiotici è stata determinata con il metodo di diffusione su dischetto. Inoltre, sono state determinate le concentrazioni minime inibenti di penicillina, ampicillina, vancomicina, teicoplanina, gentamicina e streptomicina. I geni che codificano per la resistenza a vancomicina, tetraciclina, eritromicina e i geni codificanti per alcuni fattori di virulenza sono stati identificati mediante PCR. Enterococcus hirae (54,3%) e Enterococcus faecium (25,4%) sono risultate le specie più frequentemente isolate. Nessuno dei ceppi analizzati è risultato resistente a vancomicina, teicoplanina, ampicillina o ha mostrato un elevato livello di resistenza agli aminoglicosidi (HLAR). I ceppi resistenti alla rifampicina (42,42%)sono stati quelli più frequentemente isolati seguiti da quelli resistenti al trimetoprim sulfametossazolo (33,33%). I geni tetM, tetL, vanC1 e vanC2-C3 sono stati rilevati in alcuni ceppi mentre non sono stati rilevati i geni di virulenza. Monitorare la presenza di ceppi resistenti di enterococchi fecali in animali utilizzati a scopo ricreativo è importante per prevenirne la trasmissione all'uomo e per individuare geni di resistenza o virulenza che potrebbero essere trasferiti ad altri batteri clinicamente importanti.
Fy blood group antigens are carried by the Duffy antigen receptor for chemokines (DARC), a red ce... more Fy blood group antigens are carried by the Duffy antigen receptor for chemokines (DARC), a red cells receptor for Plasmodium vivax broadly implicated in human health and diseases. Recombinant VHHs, or nanobodies, the smallest intact antigen binding fragment derivative from the heavy chain-only antibodies present in camelids, were prepared from a dromedary immunized against DARC N-terminal extracellular domain and selected for DARC binding. A described VHH, CA52, does recognize native DARC on cells. It inhibits P. vivax invasion of erythrocytes and displaces interleukin-8 bound to DARC. The targeted epitope overlaps the well-defined DARC Fy6 epitope. K D of CA52-DARC equilibrium is sub-nanomolar, hence ideal to develop diagnostic or therapeutic compounds. Immunocapture by immobilized CA52 yielded highly purified DARC from engineered K562 cells. This first report on a VHH with specificity for a red blood cell protein exemplifies VHHs' potentialities to target, to purify, and to modulate the function of cellular markers.
Journal of Applied Animal Research, 2000
Ocular lesions associated with Trypanosoma spp. infection have been described in man and many ani... more Ocular lesions associated with Trypanosoma spp. infection have been described in man and many animal species. However, loss of vision has not been demonstrated in humans presenting Chagas disease or in animals affected by different trypanosome species. In order to assess the possible ocular disorders caused by Trypanosoma evansi infection, six goats were inoculated with 1 Â 10 5 T. evansi and maintained for 12 months and four goats were used as control. The inoculated animals became positive at serological and parasitological tests at 1-month post-inoculation and showed a subclinical course of the disease. Unilateral superficial corneal ulceration and retinochoroiditis were observed in two inoculated animals. Data from ocular neurologic examination and electroretinography showed no significant differences between inoculated and non-inoculated goats. It could be concluded that Trypanosoma evansi can produce ocular lesion but without apparent loss of vision in goats. #
Journal of Equine Veterinary Science, 2013
Trypanosoma evansi was diagnosed in a camel in the Canary Islands for the first time in 1997, and... more Trypanosoma evansi was diagnosed in a camel in the Canary Islands for the first time in 1997, and the parasite is still present in a little area of the Archipelago. Since then, the disease has exclusively affected camel herds, and clinical evidence of the infection has not been demonstrated in any other animal hosts. In the frame of a control plan of the disease in the Archipelago, 864 equines located in the infected area were examined during one decade (2001-2010), of which a total of 26 (3%) were serologically positive but showed negative results at parasitological and molecular examinations. FreeCalc, an epidemiological tool to detect presence/absence of disease, showed that the population would be diseased at a confidence level of 99.916%. These results must suppose to implement the control plan against the disease including the equine population present in the surrounding area of the infected camel farms.
Revista da Sociedade Brasileira de Medicina Tropical, 2014
Trypanosoma evansi was first identified in the Canary Islands in 1997, and is still present in a ... more Trypanosoma evansi was first identified in the Canary Islands in 1997, and is still present in a small area of the Archipelago. To date, the disease has exclusively affected camel herds, and has not been detected in any other animal hosts. However potential vectors of Trypanosoma evansi must be identified. One Nzi trap was placed on a camel farm located in the infected area for a period of one year. Two thousand five hundred and five insects were trapped, of which Stomoxys calcitrans was the sole hematophagous vector captured. Stomoxys calcitrans could be exclusively responsible for the transmission of Trypanosoma evansi among camels in the surveyed area, as other species do not seem to be infected by S. calcitrans in the presence of camels.
The Canadian veterinary journal. La revue vétérinaire canadienne, 2001
Two cases of uterine prolapse in dromedary camels in a herd with concomitant cases of white muscl... more Two cases of uterine prolapse in dromedary camels in a herd with concomitant cases of white muscle disease are described. Serum selenium and glutathione peroxidase in whole blood were investigated in both patients and showed statistical difference compared with a control group. Results suggest that selenium deficiency could promote uterine prolapse in dromedary camels.
A cross-sectional study has been carried out in order to determine the prevalence of Trypanosoma ... more A cross-sectional study has been carried out in order to determine the prevalence of Trypanosoma evansi infection in susceptible hosts in the Punjab region (Pakistan). A total of 170 equines and 150 dromedary camels were examined. Five (3.3%) and 6 (4%) camels were positive at parasitological and serological examination, respectively. None of the equines tested positive at any method. These results seem to indicate that T. evansi infection has a relatively low prevalence in the Punjab region. However, efforts must be done in order to establish control measures in affected herds and avoid dissemination of the disease.
Trypanosoma evansi was diagnosed for the first time in the Canary Islands (Spain) in 1998 in a dr... more Trypanosoma evansi was diagnosed for the first time in the Canary Islands (Spain) in 1998 in a dromedary camel. Seroprevalences of 4.8% up to 9% have been observed using different diagnostic methods. Affected animals have been treated but the dissemination of the disease is unknown. This article presents an outbreak of abortions and high neonatal mortality attributable to T. evansi infection in camels as well as the clinical assessment of the affected animals. The patients were diagnosed by routine checking (three pregnant animals), after abortion (five dams), or after delivered premature or weak calves (eight dams). At clinical examination, 2 out of 16 affected animals showed moderate signs of chronic form, particularly hyporexia and intolerance to exercise. The aborted fetuses were aged 6-8 months of gestation, approximately. The main laboratorial findings were regenerative anemia (haemolytic anemia), lymphocytic and monocytic leukocytosis, hyperproteinemia, hyperglobulinemia, hypoglycaemia, serum urea increased and serum iron decreased. Treatment using trypanocidal drug (Cymelarsan 1 ) resulted highly effective. Massive treatment would be recommended in the entire camel population in the Canary Islands (less than 2000 animals), as therapeutic or preventive measure, in order to control and to achieve an eventual eradication of the disease. #
Transfusion Clinique et Biologique, 2013
faites dans du PBS contenant du BSA et du Tween 20. Pour le contrôle, 0,5 ml d'échantillon est pr... more faites dans du PBS contenant du BSA et du Tween 20. Pour le contrôle, 0,5 ml d'échantillon est préparé selon la procédure actuelle PGD et versé sur le dispositif de test PGD. Pour le prototype, 0,2 ml d'échantillon est introduit dans un tube pré-rempli d'un réactif lyophilisé, immédiatement suivi de l'addition de 0,1 ml de réactif. L'échantillon est versé dans le dispositif de test prototype PGD. Pour les deux méthodes, les intensités de signal sont évaluées visuellement vs des contrôles d'intensité. Résultats.-Pour les deux méthodes, les signaux détectés sur les lignes de capture ont été quantifiés et additionnés. Conclusion.-Dans tous les cas testés, le système prototype a produit des intensités de signal plus élevées tout en utilisant un échantillon de volume plus petit et une préparation de l'échantillon simplifiée. http://dx.Introduction.-La nature des antigènes (AG) des bactéries à Gram négatif (GN) tels que l'AG du lipopolysaccharide O et l'AG flagellaire H d'espèces comme E. coli varie largement. De nouveaux anticorps (AC) ont été développés par Verax pour une utilisation dans une version améliorée du test PGD. Méthode.-La réactivité des AC du test PGD actuels et futurs est déterminée par Elisa dans une série d'isolats de bactéries GN (E. coli, K. pneumoniae, Enterobacter spp., S. marcescens et P. aeruginosa). La solution d'AC purifiés est mise en réaction dans un puits recouvert d'un lysat de bactéries lu dans un spectrophotomètre et rapporté en densité optique (DO). Les bactéries sont cultivées une nuit dans du RPMI pour simuler la croissance dans les plaquettes. Cinq concentrations de bactéries sont préparées par dilutions au dixième. 20 l de l'anticorps couplé à de l'or colloïdal, 20 l de bactéries et 20 l d'un tampon contenant des détergents sont mélangés dans les puits d'une plaque à 96 puits. Une bandelette de 0,5 cm d'une membrane de nitrocellulose Millipore contenant l'AC de capture et une mèche absorbante est placée dans chaque puits et incubée jusqu'à ce que tout le liquide ait migré. La bandelette est rincée avec 100 l de tampon avant d'évaluer l'intensité du signal par rapport à un contrôle. Résultats.-Pour les cinq bactéries de type GN testées, les nouveaux AC ont montré une réactivité largement supérieure avec les dix souches différentes testées que les AC actuels. Conclusion.-Les nouveaux AC développés par Verax contribueront à une version améliorée du test PGD afin de mieux détecter les diverses souches de bactéries à GN les plus rencontrées dans les concentrés plaquettaires. http://dx.
Blood glutathione peroxidase (GSH-Px) levels in 709 normal dromedary camels (442 females and 267 ... more Blood glutathione peroxidase (GSH-Px) levels in 709 normal dromedary camels (442 females and 267 males) were assessed in the Canary Islands. All animals were intensively reared, and three different nutritional systems were evaluated, depending on selenium content of the diet. Mean GSH-Px level in the total population was 288.5 ± 157.2 IU⋅g -1 Hb. Reference ranges were estimated and enzymatic activities below 51 IU⋅g -1 Hb were considered inadequate. GSH-Px activities obtained in females (298.1 ± 155.7 IU⋅g -1 Hb) were significantly (P = 0.037) higher than in males (272.6 ± 157.2 IU⋅g -1 Hb). When age groups were compared, only males between 6 and 12 months old exhibited significantly lower mean GSH-Px (P = 0.006) than females. A high correlation (r = 0.88) between serum selenium concentration and blood GSH-Px activity was estimated, and the regression equation was y = 2.5101x + 42.423. Selenium content of the diet above 0.1 mg⋅kg -1 DM seems to supply adequate selenium requirements for dromedaries under intensive husbandry.
A rapid urinary iodide test was assessed in goats to validate its effectiveness in field conditio... more A rapid urinary iodide test was assessed in goats to validate its effectiveness in field conditions. The test provides a semiquantitative assessment of the iodine intake and could be valuable for animal population. Two hundred and forty-six dairy goats were randomized selected for this study. According to iodide content in urine, results were classified in three groups (30 μg/dL). These
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Papers by Carlos Gutiérrez