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Objective. To evaluate the effects of different levels of digestible lysine in diets with high energy density on productive performance and carcass characteristics of finishing pigs. Materials and Methods. Seventy crossbred barrows (initial body weight of 83.36 kg) were used and allotted in a randomized block design with five treatments, seven replications and two pigs per experimental unit. Pigs were fed ad libitum with diets containing 3.5 kcal/kg of ME and five levels of digestible lysine (0.46, 0.52, 0.58, 0.64 and 0.70%) during four weeks. Final live weight (FLW), daily feed intake (DFI), daily weight gain (DWG), feed conversion (FC), daily lysine intake (DLI), and the amount of lysine per body weight gain (DLI/DWG), were evaluated. At the end of the experiment, blood samples were taken from each pig to determine urea nitrogen concentration (UN) in serum and slaughtered to evaluate quantitative and qualitative carcass characteristics. Results. The FLW increased linearly (p<0.05).There were no differences among treatments for DFI, DWG, FC, carcass characteristics and UN. The DLI and DLI/DWG varied significantly (p<0.001) and increased linearly (p<0.001) with each lysine level. Pigs that consumed the limiting diet in lysine (0.46%) showed less DLI and DLI/DWG (p<0.001) than pigs fed the other diets. Conclusions. The amount of DLI/DWG increased with the evaluated levels of digestible lysine in diets with high energy density, without effects on productive performance and carcass characteristics of finishing pigs.

Objetivo. Evaluar los efectos de diferentes niveles de lisina digestible en dietas con alta densidad energética sobre el desempeño productivo y características de la canal de cerdos en finalización. Materiales y métodos. Se utilizaron 70 cerdos (peso inicial de 83.36 kg) mestizos castrados, distribuidos en un diseño de bloques al azar con cinco tratamientos, siete repeticiones y dos cerdos por unidad experimental. Los cerdos fueron alimentados ad libitum con dietas que contenían 3.5 Mcal/kg de energía metabolizable y cinco niveles de lisina digestible (0.46, 0.52, 0.58, 0.64 y 0.70%) durante cuatro semanas. Se evaluaron: peso vivo final (PVF), consumo diario de alimento (CDA), ganancia diaria de peso (GDP), conversión de alimento (CA), consumo diario de lisina (CDLis) y la cantidad de lisina por peso ganado (CDLis/GDP). Al final de experimento, se extrajeron muestras de sangre de todos los cerdos para determinar la concentración de nitrógeno ureico (NU) en suero sanguíneo y luego se sacrificaron para evaluar las características cualitativas y cuantitativas de la canal. Resultados. No se observaron diferencias significativas entre tratamientos para CDA, GDP, CA, características de la canal y NU. El PVF incrementó linealmente (p<0.05). El CDLis y la CDLis/GDP variaron significativamente (p<0.001) e incrementaron linealmente (p<0.001) con cada nivel de lisina. Los cerdos que consumieron la dieta limitante en lisina (0.46%) mostraron menor consumo y CDLis/GDP (p<0.001) que los cerdos alimentados con las otras dietas. Conclusiones. Los niveles de lisina digestible evaluados en dietas con alta densidad energética aumentan la CDLis/GDP, sin efectos sobre el desempeño productivo y las características de la canal de los cerdos en finalización.

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Para evaluar el efecto de la harina de girasol (HG) y dos complejos enzimáticos (CE) sobre el desempeño productivo de pollos de engorde en fase de finalización, se distribuyeron 720 pollos mediante un diseño completamente aleatorizado con arreglo factorial 2 x 3, dos niveles de inclusión de HG: 0 y 3%; tres niveles de inclusión de CE: sin CE (SCE), con CE tipo A (con actividad de las enzimas proteasas y celulasas; CEA) y con CE tipo B (con actividad de las enzimas xilanasas y b-glucanasas; CEB), con seis repeticiones de 20 pollos cada una. El factor CE afectó al adicionar el CEB, obteniendo conversión de alimento (P=0,032) de 1,555, índice de eficiencia europea (P=0,007) de 377,13, rendimiento de canal (P=0,012) de 76,69%, rendimiento de pechuga (P=0,044) de 24,86%. Para la interacción de factores se obtuvo un consumo de alimento (P=0,005) de 2.596,90 g (3% HG+SCE), conversión de alimento (P=0,0009) de 1,513 (0% HG+CEA), índice de eficiencia europea (P=0,0011) similares de 399,86 (0% HG+CEA) y 379,98 (3% HG + CEB), la dieta 3% HG+CEB con rendimiento de canal (P=0,0024) de 77,14% y rendimiento de pechuga (P=0,044) de 25,72%. Estos resultados demuestran que adicionando 3% HG no se afecta el desempeño productivo y la adición de ambos CE generan resultados positivos, con mayor eficiencia del CEB, obteniendo respuestas económicamente viables para la alimentación de los pollos de engorde.

To evaluate the effect of sunflower meal (SM) and two enzyme complexes (EC) on the performance of finishing broilers, 720 broilers were distributed through a completely randomized design 2 x 3 factorial arrangement, two levels with inclusion sunflower meal (SM); 0 and 3%; including three levels of EC; without EC (NEC), with EC A; (with activity of proteases and cellulases; ECA) and EC B enzymes, with activity the b-glucanase and xylanase enzymes; CEB, with six replicates of 20 broilers each. The CE factor affected by adding the CEB, obtaining feed conversion (P=0.032) 1.555, european efficiency index (P=0.007) of 377.13, carcass yield (P=0.012) of 76.69%, breast yield (P=0.044) of 24.86%. For the interaction of factors was obtained a feed intake (P=0.005) of 2596.90 g (3%SM+NEC), feed conversion (P=0.0009) of 1,513 (0%SM+CEA), similar index european Efficiency (P = 0.0011) of 399.86 (0% SM + CEA) and 379.98 (3%SM+CEB), the diet 3% SM + ECB with carcass yield (P=0.0024) of 77.14% and breast yield (P=0.044) of 25.72%. These results demonstrate that adding 3% HG do not affect production performance and the addition of both EC generate positive results, more efficiently ECB, obtaining a performance viable economically for broilers feeding.

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Para determinar el efecto de dos tipos de material de cama sobre la carga parasitaria de cerdos en crecimiento y engorde alojados en cama profunda, se realizó un ensayo utilizando 92 cerdos machos inmunocastrados, con peso inicial promedio de 30 kg y 70 d de edad, hasta peso de finalización. Se utilizó un diseño completamente al azar, con dos tratamientos basados en el material de cama, heno de gramíneas (HG) y concha de arroz (CA), con seis réplicas y 46 animales/tratamiento distribuidos según una densidad de 1,37 cerdos/m². Se administró ad libitum un alimento comercial. Durante 90 d se evaluó la cantidad de material de cama requerido por animal (CCA), la humedad de la cama (HC), emisión de amonio (EAC), composición química de la cama, zonas de uso (% área limpia y sucia), presencia de ectoparásitos (PE), carga parasitaria en la cama (CPC) y heces de los cerdos (CPH). Los datos obtenidos fueron analizados utilizando el método PROC GENMOD del paquete estadístico SAS. Se encontraron diferencias significativas (P< 0,05) entre HG y CA, para las variables CCA (107,32 y 84,157 kg/animal/ciclo), EAC (9,462 y 3,3274 ppm), PE (14,04 y 4,34 moscas/animal/d), zonas de uso y composición química de la cama en sus fracciones de nitrógeno, proteína, fibra, grasa cruda, ceniza y fósforo. No se encontraron diferencias significativas para CPC, pero si para CPH. La CA presentó características de HC, EAC, CPH y zonas de uso más favorables que la HG. La presencia de ectoparásitos fue mayor en los cerdos alojados en cama con HG. Además, se requirió menor cantidad de material de cama por animal en CA comparado con HG.

To determine the effect of two types of bedding material on parasitic burden in growing and fattening pigs housed in deep litter, an assay was conducted using 92 immune castrated males, with an average initial weight of 30.00 kg and 70 days old until finalization weight. A completely randomized design was used, with two treatments based on bedding material, as follows: grass hay (GH) and rice husk (RH), with six replicates/treatment and 46 animals/treatment, according to a density of 1.37 pigs/m². A commercial feed was given ad libitum. During the course of 90 days was evaluated: amount of bedding material required per animal (ABA), bedding moisture (BM) ammonia emission (AE), chemical composition of the bed, areas of use (% of clean and dirty area), presence of ectoparasites (PE), parasite burden in bed (PBB) and feces of pigs (PBF). The data obtained were analyzed using the PROC GENMOD methodology, of the Statistical Analysis System (SAS). Statistically significant (P<0.05) differences were found between GH and RH for the variables ABA (107.32 and 84.157 kg/animal/cycle), AE (9.462 and 3.3274 ppm), PE (14.04, and 4.34 flies/animal/day), areas of use and chemical composition of the bed in their nitrogen, protein, fiber, crude fat, ash and phosphorus fractions:. No significant differences between treatments were found for PBB. In contrast, significant differences were shown for PBF. The presence of ectoparasites in pigs housed in deep litter with HG was greater. Additionally, a less amount of bed material was required per animal with RH, in comparison with HG.

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Objetivo. Evaluar el efecto de la harina de pijiguao y lisina sintética sobre los lípidos sanguíneos de cerdos en crecimiento y engorde. Materiales y métodos. El estudio se realizó en dos etapas. En la primera etapa se utilizaron 72 cerdos castrados en crecimiento de 30 ± 0.5 kg, en un arreglo factorial 2x3: dos niveles de lisina sintética (0 y 2.70 g/kg) y tres niveles de harina de pijiguao (0, 160 y 320 g/kg). En la segunda etapa se utilizaron 16 cerdos en engorde de 67.25 ± 1.17 kg, en un arreglo factorial 2x2: dos niveles de lisina sintética (0 y 2.70 g/kg) y dos niveles de pijiguao (0 y 175 g/kg). Se determinaron las concentraciones séricas de triacilgliceroles, colesterol total y ácidos grasos. Resultados. Los cerdos en crecimiento que consumieron pijiguao presentaron menores (p<0.001) concentraciones de colesterol que el grupo control (2.27 y 2.23 mmol/l vs 2.56 mmol/l) y triacilgliceroles (0.34 y 0.28 mmol/l vs 0.42 mmol/l). El ácido oleico incrementó (p<0.01) con el mayor nivel de pijiguao (20.78% a 28.84%), y la lisina aumentó (p<0.05) el ácido linoleico (27.83% a 31.29%). Los cerdos alimentados con pijiguao y lisina mostraron menor (p<0.001) ácido palmítico que el grupo con pijiguao sin lisina (0.23 y 0.19% vs 0.45 y 0.62%, respectivamente). En la etapa de engorde los triacilgliceroles disminuyeron (p<0.05) en los cerdos alimentados con pijiguao y lisina (0.46 a 0.36 mmol/l). Los cerdos alimentados con pijiguao mostraron menor ácido linoleico y mayor ácido oleico (p<0.001). Conclusiones. Las dietas con pijiguao y lisina sintética no causaron efectos negativos sobre los lípidos sanguíneos de cerdos.

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Streptococcus pneumoniae and Staphylococcus aureus cause significant morbidity and mortality worldwide. We investigated both the colonization and co-colonization characteristics for these pathogens among 250 healthy children from 2 to 5 years of age in Merida, Venezuela, in 2007. The prevalence of S. pneumoniae colonization, S. aureus colonization, and S. pneumoniae-S. aureus co-colonization was 28%, 56%, and 16%, respectively. Pneumococcal serotypes 6B (14%), 19F (12%), 23F (12%), 15 (9%), 6A (8%), 11 (8%), 23A (6%), and 34 (6%) were the most prevalent. Non-respiratory atopy was a risk factor for S. aureus colonization (p = 0.017). Vaccine serotypes were negatively associated with preceding respiratory infection (p = 0.02) and with S. aureus colonization (p = 0.03). We observed a high prevalence of pneumococcal resistance against trimethoprim-sulfamethoxazole (40%), erythromycin (38%), and penicillin (14%). Semi-quantitative measurement of pneumococcal colonization density showed that children with young siblings and low socioeconomic status were more densely colonized (p = 0.02 and p = 0.02, respectively). In contrast, trimethoprim-sulfamethoxazole- and multidrug-resistant-pneumococci colonized children sparsely (p = 0.03 and p = 0.01, respectively). Our data form an important basis to monitor the future impact of pneumococcal vaccination on bacterial colonization, as well as to recommend a rationalized and restrictive antimicrobial use in our community.

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In North America, the indigenous groups have been identified as a population with increased risk of pneumococcal colonization and pneumococcal invasive disease. However, little information is available from South American natives. In the present study we evaluated the nasopharyngeal carriage and serotype distribution of Streptococcus pneumoniae in mothers and children of the Panare people from Venezuela. In May 2008, in 8 distinct geographically isolated communities, 148 nasopharyngeal samples were obtained from 64 healthy mothers and 84 healthy Panare children under 5 years of age. S. pneumoniae was isolated and identified by standard techniques. Strains were typified by multiplex PCR and resistance patterns were determined by the disk diffusion method. A total of 65 strains were isolated; 11% of the mothers and 69% of the children carried S. pneumoniae. Serotypes 6B (48%), 33F (21,5%), 6A (6%), 19A (3,1%) and 23F (1,5%) were the most predominant. Of the 6 colonized mother-child pairs, 3 pairs (2 with 6B), were colonized with the same serotype. All strains were sensitive to penicillin and 13,7% were resistant to macrolides. The high colonization rates in the Panare people suggest that the children are at increased risk of pneumococcal invasive disease and could benefit from vaccination. Four conjugate vaccine serotypes (6B, 6A, 19A and 23F) representing 58 % of all strains were present in the population at the moment of sampling. Resistance to antibiotics is (still) not a problem.

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Se estudia la transferencia de mercurio y cadmio desde el sistema suelo hacia Brachiaria dictyoneura en función de la capacidad bioindicadora y bioacumuladora. Durante la evaluación de cadmio en B. dictyoneura se observó una disminución en el crecimiento del 65%. La toxicidad de cadmio se correlaciona con la acumulación consecutiva del catión durante el tiempo de monitoreo. En el tratamiento con mercurio, a partir de los 30 días de exposición, se observó disminución en el contenido del catión en la planta, presentando posiblemente fitorreducción de mercurio Hg2+ a Hg0 y posterior evaporación. La tolerancia y la capacidad acumuladora de B. dictyoneura podrían ser utilizadas para fitoremediación en sitios co-contaminados por Cd y Hg.

The transfer of mercury and cadmium in Brachiaria dictyoneura was studied in terms of bioaccumulative capacity and as a bioindicator. During the evaluation cadmium in B. dictyoneura show a decrease of 65%. The toxicity of cadmium was correlated with the consecutive accumulation of the cation during the monitoring time. With respect to mercury, a decrease in cation content in the plant was observed 30 days after exposure, presenting possible phytoreductión of mercury ion Hg2+ to Hg0 in B. dictyoneura and subsequent evaporation. The tolerance and accumulator capacity of B. dictyoneura could be used for phytoremediation of sites co-contaminated with Cd and Hg.

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En este trabajo se estudia el efecto de las emulsiones O/W de ácido oleico-nicotina estabilizadas con Tween 80® sobre su actividad insecticida aguda y crónica en Drosophila melanogaster. La bioactividad aguda de las emulsiones de ácido oleico-nicotina registró un tiempo letal medio (TL50 = 13 ± 3 minutos) significativamente mayor que el obtenido con la nicotina en solución acuosa (TL50 = 7 ± 1 minutos). La baja bioactividad de la emulsión de ácido oleico-nicotina presenta una alta correlación con el porcentaje de nicotina encapsulada en las gotas de emulsión. La bioactividad crónica se evaluó en el ciclo de vida de D. melanogaster, donde se observó repelencia, evidenciada por la disminución en la oviposición.

This paper studies the effect of the O/W emulsion of oleic acid-nicotine stabilized with Tween 80® on its acute and chronic insecticidal activity in Drosophila melanogaster. The oleic acid-nicotine emulsions acute bioactivity show a median lethal time (LT50 = 13 ± 3 minutes) significantly higher compared with that obtained with nicotine in aqueous solution (LT50 = 7 ± 1 minutes). Oleic acid-nicotine emulsion low bioactivity present high correlation with the percentage of nicotine encapsulated in emulsion droplets. The chronic bioactivity is assessed in the life cycle of D. melanogaster where diminution in oviposition is taken as evidence of repellency.

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In order to study the genetic variability of Mycobacterium tuberculosis circulating in the Carabobo State at Venezuela, 317 strains of M. tuberculosis isolated from patients living in different health districts whose acid fast smears were positive, were included. Each strain was characterized by spoligotyping and the pattern compared with the national and worldwide SpolDB4.0 databases; 220 isolates (69.4%) were grouped in 24 clusters, being LAM the most common family (34%). In contrast to other Venezuelan regions, the most common Carabobo spoligotype was number 605, with 46 isolates (14.5%). In addition, there were 97 (30.6%) orphan spoligotypes, 19 of which are found in SpolDB4.0, and 78 non described. Co-infection with human immunodeficiency virus was detected in 11 patients (3.5%). These results show high genotypic variability of M. tuberculosis in the region, contributing with new information for a better understanding of tuberculosis transmission in Venezuela.

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In order to study the genetic variability oí Mycobacterium tuberculosis circulating in the Carabobo State at Venezuela, 317 strains of M. tuberculosis isolated from patients living in different health districts whose acid fast smears were positive, were included. Each strain was characterized by spoligotyping and the pattern compared with the national and worldwide SpolDB4.0 databases; 220 isolates (69.4 percent) were grouped in 24 clusters, being LAM the most common family (34 percent). In contrast to other Venezuelan regions, the most common Carabobo spoligotype was number 605, with 46 isolates (14.5 percent). In addition, there were 97 (30.6 percent) orphan spoligotypes, 19 of which are found in SpolDB4.0, and 78 non described. Co-infection with human irnmunodeficiency virus was detected in 11 patients (3.5 percent). These results show high genotypic variability of M. tuberculosis in the región, contributing with new information for a better understanding of tuberculosis transmission in Venezuela.

Con el objeto de estudiar la variabilidad genética de las cepas de Mycobacterium tuberculosis circulantes en el Estado Carabobo, Venezuela, se empleó la técnica de spoligotyping para caracterizar 317 cepas de M. tuberculosis aisladas de pacientes con baciloscopia y cultivo positivo, residentes en diferentes distritos sanitarios. Los espoligotipos obtenidos se contrastaron con la base de datos nacional y mundial (SpolDB4.0); 220 aislados (69,4 por ciento) se agruparon en 24 clusters, con predominio de la familia LAM (34 por ciento). A diferencia de otras regiones venezolanas, el espoligotipo 605 fue el más frecuente con 46 aislados (14,5 por ciento). Se identificaron 97 (30,6 por cientoo) aislados únicos, 19 reportados en SpolDB4.0 y 78 no descritos. Co-infección con el virus de inmunodeficiencia humana se detectó en 11 pacientes (3,5 por cientoo). Los resultados son un aporte al estudio de la transmisión de la tuberculosis a nivel regional y nacional y sugieren que existen diferencias regionales en las cepas más comunes. La cepa 605, poco común fuera de Venezuela, requiere de estudios epidemiológicos adicionales.

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Twelve Klebsiella pneumoniae isolates resistant to expanded-spectrum cephalosporins and aztreonam, from patients with nosocomial septicaemia at the intensive care unit of the Andes University Hospital, Mérida, Venezuela, were studied for production of extended-spectrum beta-lactamase (ESbetaL) activity. All were also resistant to gentamicin, kanamycin, tetracycline and chloramphenicol but sensitive to cefoxitin, imipenem, amikacin and tobramycin. Production of ESbetaL activity was confirmed by restoring susceptibility to ceftazidime in the presence of clavulanic acid. All isolates carried an identical plasmid of approximately 87 kb. Resistance to beta-lactams, aminoglycosides, tetracycline and chloramphenicol was lost en bloc after plasmid curing by treatment with acridine orange and was transferable en bloc to Escherichia coli by conjugation. Transconjugants always showed the same plasmid profile as that of Klebsiella donors. Isoelectric focusing analysis of the crude extracts of transconjugants showed in all cases, the presence of two beta-lactamases of pI 5.4 and 8.2. Analysis of the plasmid carried by one of the transconjugants by means of hybridization assays, revealed the presence of both bla(TEM) and bla(SHV) determinants. Cloning and sequencing of each determinant identified them as bla(TEM-1) and bla(SHV-5), respectively, the latter being responsible for the ESbetaL activity. Results of this study indicate that ESbetaL determinants of the SHV-type carried by transferable elements, are spreading among nosocomial isolates of K. pneumoniae in Mérida, Venezuela.

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A total of 57 strains of Shigella (36 S sonnei, 21 S flexneri), isolated from children with acute diarrheal disease who presented for treatment at the Andes University Hospital, Merida, Venezuela, from June 1993 to June 1995, were tested for their susceptibility to trimethoprim, sulfamethoxazole, ampicillin, cefamandole, ceftriaxone, streptomycin, fleroxacin, and nalidixic acid, by the agar dilution method. Twenty-seven strains (75%) of S sonnei and eight strains of S flexneri (38.1%) isolates showed high-level resistance to trimethoprim (MIC90 > 1024 microg/mL), which was also associated with other resistance patterns. The most common resistant phenotype associated with trimethoprim-resistance among S sonnei isolates was sulfamethoxazole-streptomycin (63%); among S flexneri isolates, it was sulfamethoxazole-ampicillin-streptomycin (87.5%). Individual resistance was only observed for ampicillin, mainly in four isolates of S flexneri, and in one isolate of S sonnei. Most Shigella strains were resistant to three or more antimicrobial agents. These results confirmed that multiresistant strains of Shigella are present in Merida, and emphasize the importance to maintain these under surveillance in order to assess local susceptibility patterns and empiric therapy.

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In order to evaluate the in vitro activity of fleroxacin against nosocomial gram-negative organisms, 263 multiresistant gram-negative bacilli (203 Enterobacteriaceae and 60 non-fermenting gram-negative bacilli) were isolated from adult patients with nosocomial infections. The different patterns of resistance to eight different antimicrobial agents (ampicillin, carbenicillin, piperacillin, cephalothin, cefamandole, ceftazidime, gentamicin and amikacin) were determined by minimum inhibitory concentration (MIC), using the agar dilution method. The most prevalent multiresistant species isolated were Klebsiella pneumoniae (28.9%), Escherichia coli (24%) and Pseudomonas aeruginosa (12.2%). All these bacterial strains showed three to five resistance patterns to at least three different antibiotics. Resistance to ceftazidime was observed in at least one of the resistance patterns of isolated bacteria. The activity of fleroxacin against multiresistant enteric bacteria was excellent; these strains showed a susceptibility of 79-100%. The susceptibility of P. aeruginosa to antipseudomonal agents was low; however, the activity of fleroxacin against these strains was higher than 60% (MIC < or = 2 microg/ ml), broadly comparable with ciprofloxacin. The resistance to fluoroquinolones detected in this study was no cause for alarm (3%). Consequently, fleroxacin maintains a remarkable activity against Enterobacteriaceae and remains highly active against other gram-negative bacilli. Nevertheless, actions directed at preventing or limiting resistance will be crucial to maintain the viability of fluoroquinolones as important therapeutic agents.

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BACKGROUND: The genetic and molecular mechanisms involved in antimicrobial resistance of 10 strains of gramnegative bacilli (1 Serratia marcescens; 2 Escherichia coli; 1 Proteus mirabilis; 4 Klebsiella pneumoniae; 1 Enterobacter cloacae y 1 Alcaligenes faecalis), isolated from adult patients with nosocomial pulmonary infection at the in-patient facilities of the University Hospital of Los Andes, Mérida, Venezuela, have been studied. METHODS: The antimicrobial susceptibility was determined by minimum inhibitory concentrations using the dilution method in agar. The study of extrachromosomal genes was carried out by conjugation, bacterial infection with the bacteriophage M13 and curing of plasmid by acridine orange. The plasmids were isolated by alkaline lysis and analysis of restriction endonuclease digestion was carried out separately using the enzymes EcoRI and HindIII. A DNA probe, derived from the region which encodes the TEM-1 beta-lactamase of the plasmid pBR322 was used for dot-blot hybridization tests. RESULTS: All of the gramnegative bacilli showed resistance to ampicillin, carbenicillin and cephalothin (> 128 micrograms/ml) and 3 strains also showed resistance to gentamicin (> 64 micrograms/ml). Genetic and molecular procedures showed the presence of conjugative plasmids of approximately 54 kb in all the 10 strains. The restriction patterns obtained by using EcoRI and HindIII indicated common DNA fragments in most of the plasmids studied. The dot-blot hybridization tests confirmed homology between the plasmids and the DNA probe used (TEM-1 beta-lactamase). CONCLUSIONS: In this study, the gramnegative bacteria of nosocomial origin harbored self-transferable plasmids of approximately 54 kb, which mediate resistance to gentamicin and encode a beta-lactamase of the TEM group.

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