Universidade de Trás-os-Montes e Alto Douro (UTAD)
Departamento de Ciências Veterinárias
Lyme borreliosis is the most common tick-borne zoonosis in the northern hemisphere. Several vertebrates are crucial in the epidemiological cycle of Borrelia burgdorferi sensu lato, but the role of wild boar as a reservoir is still... more
Lyme borreliosis is the most common tick-borne zoonosis in the northern hemisphere. Several vertebrates are crucial in the epidemiological cycle of Borrelia burgdorferi sensu lato, but the role of wild boar as a reservoir is still unknown. Sera were collected from 90 wild boars shot in the Trás-os-Montes region, Northern Portugal (hunting season 2011/2012). In this study, Borrelia DNA was detected for the first time by nested-PCR in three different sera, suggesting that the wild boar may be a potential reservoir for this spirochete. Sequencing results show 100% similarity with Borrelia afzelii. Further studies are needed to evaluate the public health risks associated with boar hunting.
Borrelia miyamotoi, a relapsing fever spirochete, has been found recently in Ixodes ricinus ticks; however, little is known about its spatial distribution and potential local impact on human health. A total of 640 ticks (447 nymphs and... more
Borrelia miyamotoi, a relapsing fever spirochete, has been found recently in Ixodes ricinus ticks; however, little is known about its spatial distribution and potential local impact on human health. A total of 640 ticks (447 nymphs and 193 adults) collected throughout Portugal were analyzed using two nested PCR protocols, one targeting the flagellin gene and the other the internal transcribed space region between the 5S and the 23S rRNA. As a result, B. miyamotoi was detected, for the first time, in one guesting I. ricinus nymph collected in the Lisboa district. In addition, a prevalence of 11% (71/640) for B. burgdorferi sensu lato was obtained. Even though no human relapsing fever cases due to infection by B. miyamotoi have been reported yet in Portugal, surveillance must be improved to provide better insight into the prevalence and distribution of this spirochete in ticks.
SUMMARY Leptospirosis is a zoonosis of worldwide distribution, caused by infection with pathogenic spirochaetes of the genus Leptospira. The wild boar (Sus scrofa), an important hunting species in Europe, seems to play a significant role... more
SUMMARY Leptospirosis is a zoonosis of worldwide distribution, caused by infection with pathogenic spirochaetes of the genus Leptospira. The wild boar (Sus scrofa), an important hunting species in Europe, seems to play a significant role in the epidemiological cycle of leptospirosis. A total of 101 serum samples from wild boar hunted in Northern Portugal were analysed for leptospiral antibodies detection by microscopic agglutination test. Sera were collected during hunting seasons (2011-2013) and tested with 17 different pathogenic serovars of Leptospira. Antibodies against nine serovars were detected in 66 (65·4%) of these sera. Serovars Tarassovi and Altodouro exhibited the highest seroreactivity rates (23·8% and 16·8%, respectively), followed by Autumnalis (7·9%) and Bratislava (6·9%). Age and district of origin were found to be risk factors for the presence of leptospiral antibodies in contrast to gender. From a One Health perspective, this study revealed that wild boar should be considered as a potential source of leptospirosis dissemination for humans and animal species (domestic and wild) in shared environments, particularly in the Trás-os-Montes region.
Lyme borreliosis is the most common tick-borne zoonosis in the northern hemisphere. Several vertebrates are crucial in the epidemiological cycle of Borrelia burgdorferi sensu lato, but the role of wild boar as a reservoir is still... more
Lyme borreliosis is the most common tick-borne zoonosis in the northern hemisphere. Several vertebrates are crucial in the epidemiological cycle of Borrelia burgdorferi sensu lato, but the role of wild boar as a reservoir is still unknown. Sera were collected from 90 wild boars shot in the Trás-os-Montes region, Northern Portugal (hunting season 2011/2012). In this study, Borrelia DNA was detected for the first time by nested-PCR in three different sera, suggesting that the wild boar may be a potential reservoir for this spirochete. Sequencing results show 100% similarity with Borrelia afzelii. Further studies are needed to evaluate the public health risks associated with boar hunting.
PCR-based methods of fingerprinting take advantage of the presence of repetitive sequences that are interspersed throughout the genome of diverse bacterial species. They include the repetitive extragenic palindromic (REP) sequence, the... more
PCR-based methods of fingerprinting take advantage of the presence of repetitive sequences that are interspersed throughout the genome of diverse bacterial species. They include the repetitive extragenic palindromic (REP) sequence, the enterobacterial repetitive intergenic consensus sequence (ERIC) and the 154-bp BOX element. The combination of the three methods is used for fine discrimination of strains and is designated as rep-polymerase chain reaction (PCR). REP-PCR and ERIC-PCR have been shown to be useful for typing Aeromonas strains. To our knowledge, rep-PCR fingerprinting method using the BOXA1R primer has never been tested on aeromonads. In this study, the BOX-PCR fingerprinting technique was evaluated for the discrimination of strains of some Aeromonas species. All strains were typeable and the majority showed unique banding patterns. Four strains from culture collections were used to investigate the reproducibility of the method. According to our results, BOX-PCR fingerprinting is applicable for typing of Aeromonas strains and can be considered as a useful complementary tool for epidemiological studies of members of this genus.
- by Artur Alves and +2
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- Bacteriology
Bacterial infections caused by members of the genus Aeromonas, with a relatively high antibiotic resistance, are among the most common and troublesome diseases of fish raised in ponds with recirculation systems. In this study, carried out... more
Bacterial infections caused by members of the genus Aeromonas, with a relatively high antibiotic resistance, are among the most common and troublesome diseases of fish raised in ponds with recirculation systems. In this study, carried out at an experimental aquaculture station in northern Portugal, 51 strains identified as belonging to the genus Aeromonas were isolated from 20 rainbow trout (Oncorhynchus mykiss) skin and kidney samples, as well as from raceway water samples. Macro- and microscopic examination of the fish tissues revealed lesions or cellular alterations in skin and kidney that seemed to correlate with the presence of those isolates. The sensitivity of all isolated strains to different groups of beta-lactam antibiotics (penicillins, cephalosporins, monobactams and carbapenems) was evaluated using the disc diffusion method. The highest rates of resistance were to amoxicillin, carbenicillin and ticarcillin. Unexpected resistance to imipenem, an antibiotic of clinical us...
The first description of the species Aeromonas allosaccharophila was only based on two strains (the type strain CECT4199, and a duplicate CECT4200) isolated from diseased elvers (Anguilla anguilla) of an eel-farm located in Valencia,... more
The first description of the species Aeromonas allosaccharophila was only based on two strains (the type strain CECT4199, and a duplicate CECT4200) isolated from diseased elvers (Anguilla anguilla) of an eel-farm located in Valencia, Spain, and one stool isolate (ATCC35942) from a female with diarrhoea and food poisoning in South Carolina, U.S.A. In the present study, 17 Aeromonas isolates obtained from carcasses of pigs and from the equipment for the cleaning process, and one strain recently isolated from a clinical case of gastroenteritis, were genetically identified as Aerornonas allosaccharophila on the basis of gyrB and 16S rRNA gene sequencing. In addition, this phylogenetic approach also supports the classification of Aeromonas veronii biogroup sobria reference strains LMG13071, LMG13073 and LMG13074 within the species A. allosaccharophila. The A. allosaccharophila strains isolated from pig carcasses processed in a single slaughterhouse presented a clonal origin, on the basis of random amplified polymorphic DNA genetic typing. To our knowledge, this is the first time since the species description that A. allosaccharophila has been newly identified, being on this occasion isolated from the environment of a slaughterhouse. Our findings indicate that this species may be readily identified by a sequencing approach and, consequently, the present work supports the existence of this phylogenetic cluster.
ABSTRACT This is a novel study of phenolic content and synergistic effects between extracts and Eucalyptus globulus leaves essential oil and antibiotics against several isolates from respiratory tract infections (Pseudomonas aeruginosa).... more
ABSTRACT This is a novel study of phenolic content and synergistic effects between extracts and Eucalyptus globulus leaves essential oil and antibiotics against several isolates from respiratory tract infections (Pseudomonas aeruginosa). The extraction yield obtained with polar solvents was substantially higher, with the maximum value found for methanol 70%, followed by methanol 100% and water. Of the 16 isolates tested, only 4 (MJH 4, MJH 15, MJH 21 and MJH 40) revealed susceptibly to the extracts tested. The MJH 4 revealed the highest susceptibility of the 5 extracts tested (water, 70% methanol, 100% methanol, 100% acetone and 100% dichloromethane). The isolates tested showed the highest susceptibility to the extracts with higher phenolic compounds content, i.e. the methanolics. The highest inhibition halo value obtained was observed for the oil B against the isolate MJH 4 (19.3 mm), while the minimum value was obtained against the isolate MJH 207 (7.7 mm) with oil A. The MIC (minimum inhibitory concentration) value for the extracts ranged between 625.0 μg/mL and 2500.0 μg/mL, while it was also observed that the essential oil B was more efficient than oil A. The combination between antibiotic and extracts or essential oils demonstrated an additive effect in 55% of the cases, meaning that the combined use of antibiotic and the compound tested (extract or essential oil) revealed an increase of antibacterial activity. The use of these compounds (extracts and oils) of E. globulus may represent an important source of bioactive compounds and an alternative for the treatment of respiratory infectious diseases caused by P. aeruginosa.
- by Maria Saavedra
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