Faecal samples of healthy dogs (n=39) and cats (n=36) obtained in Northern Portugal were seeded on Levine agar plates, and two Escherichia coli isolates per sample were recovered (78 of dogs and 66 of cats). The susceptibility to 16 antimicrobial agents was tested in this series of 144 E. coli isolates. Almost 20% of them showed tetracycline resistance and 12 and 15% presented ampicillin or streptomycin resistance, respectively. The percentage of resistance to the other antimicrobial agents was in all cases below 4%, and no resistant isolates were detected for ceftazidime, imipenem, cefoxitin or amikacin. Two isolates (from one dog) showed cefotaxime-resistance and harboured both the CTX-M-1 and OXA-30 beta-lactamases. A bla(TEM) gene was detected in 12 of 17 ampicillin-resistant isolates, the aac(3)-II gene in the three gentamicin-resistant isolates, aadA in 7 of 22 streptomycin-resistant isolates, and tet(A) and/or tet(B) gene in all 28 tetracycline-resistant isolates. The gene encoding class 1 integrase was detected in six E. coli isolates, including the four trimethoprim-sulfamethoxazole-resistant isolates and those two harbouring CTX-M-1 and OXA-30 beta-lactamases; different gene cassette arrangements were identified: dfrA1+aadA1 (two isolates), dfrA12+orfF+aadA2 (two isolates) and bla(OXA30)+aadA1 (two isolates). One amino acid change in GyrA protein (Ser83Leu or Asp87Tyr) was detected in four nalidixic acid-resistant and ciprofloxacin-susceptible isolates and two amino acid changes in GyrA (Ser83Leu+Asp87Asn) and one in ParC (Ser80Ile) were identified in one nalidixic acid- and ciprofloxacin-resistant isolate. Faecal E. coli isolates of healthy pets could be a reservoir of antimicrobial resistance genes.
Seventy-six faecal samples were obtained from broilers at slaughterhouse level in Portugal. Samples were inoculated on cefotaxime-supplemented Levine agar plates. Cefotaxime-resistant Escherichia coli isolates were recovered from 32 samples (42.1%), obtaining a total of 34 E. coli isolates (one or two isolates per sample). Susceptibility to 16 antibiotics was studied by disk diffusion method, and 85% of the isolates presented a phenotype of multi-resistance that included antimicrobial agents of at least four different families. Extended-spectrum-beta-lactamases (ESBL) of the TEM and CTX-M groups were detected in 31 ESBL-positive E. coli isolates. Twenty-six isolates harboured the bla(TEM-52) gene and two of them also harboured bla(TEM-1b). The bla(CTX-M-14) gene was identified in three isolates (in association with bla(TEM-1b) in one of them), and bla(CTX-M-32) was demonstrated in two additional isolates. Three of the 34 cefotaxime-resistant isolates (9%) did not produce ESBLs, and two of them presented mutations at positions -42 (C-->T), -18 (G-->A), -1 (C-->T), and +58(C-->T) of the promoter/attenuator region of ampC gene. tet(A) and/or tet(B) genes were detected in all 34 tetracycline-resistant isolates, aadA in all 26 streptomycin-resistant isolates; cmlA in 3 of 6 chloramphenicol-resistant isolates, and aac(3)-II or aac(3)-I + aac(3)-IV genes in all 4 gentamicin-resistant isolates. Different combinations of sul1, sul2 and sul3 genes were demonstrated among the 22 trimethoprim-sulfamethoxazole-resistant isolates. Amino acid changes in GyrA and ParC proteins were identified in all 18 ciprofloxacin-resistant isolates. The results of this study indicate that the intestinal tract of healthy poultry is a reservoir of ESBL-positive E. coli isolates.
Seventy-two fecal samples obtained from wild animals in Portugal were sampled on Levine agar plates (non-supplemented with antibiotics), and Escherichia coli isolates were recovered from 56 of them (78%), obtaining a total of 112 E. coli isolates (two per sample). Susceptibility to 16 antibiotics was studied in these isolates, and the following percentages of resistance were obtained: tetracycline, streptomycin, ampicillin, and trimethoprim-sulfamethoxazole (SXT) (range 19-35%); nalidixic acid (14%); ciprofloxacin (9%); amoxicillin-clavulanic acid, gentamicin, tobramycin, and chloramphenicol (range 4.5-7%); cefotaxime, and aztreonam (1.8%); ceftazidime (0.9%); and amikacin, cefoxitin, and imipenem (0%). A bla(TEM) gene was found in 22 of the 25 ampicillin-resistant isolates, and the gene encoding CTX-M-14 beta-lactamase was identified in the two cefotaxime-resistant isolates (recovered from a common kestrel and a sparrowhawk), associated with bla(TEM-52) gene in one of them. Other resistance genes detected were as follows: aac(3)-II or aac(3)-IV genes in all gentamicin-resistant isolates; aadA1 or aadA2 in 22 of 25 streptomycin-resistant isolates; tet(A) and/or tet(B) in all 39 tetracycline-resistant isolates; and sul1 and/or sul2 and/or sul3 genes in all 21 SXT-resistant isolates. Two amino acid changes in GyrA protein (Ser83Leu + Asp87Asn) and one change in ParC protein (Ser80Ile) were identified in all 10 ciprofloxacin-resistant isolates of our series. The intestinal tract of wild animals is a reservoir of antibiotic resistance genes, especially for ampicillin, tetracycline, streptomycin, and SXT, and it is also remarkable that multiresistant E. coli isolates are detected in some of the tested animals.
Advances and research in biotechnology have applications over a wide range of areas, such as microbiology, medicine, the food industry, agriculture, genetically modified organisms, and nanotechnology, among others. However, research with pathogenic agents, such as virus, parasites, fungi, rickettsia, bacterial microorganisms, or genetic modified organisms, has generated concern because of their potential biological risk – not only for people, but also for the environment due to their unpredictable behavior. In addition, concern for biosafety is associated with the emergence of new diseases or re-emergence of diseases that were already under control. Biotechnology laboratories require biosafety measures designed to protect their staff, the population, and the environment, which may be exposed to hazardous organisms and materials. Laboratory staff training and education is essential, not only to acquire a good understanding about the direct handling of hazardous biological agents but also knowledge of the epidemiology, pathogenicity, and human susceptibility to the biological materials used in research. Biological risk can be reduced and controlled by the correct application of internationally recognized procedures such as proper microbiological techniques, proper containment apparatus, adequate facilities, protective barriers, and special training and education of laboratory workers. To avoid occupational infections, knowledge about standardized microbiological procedures and techniques and the use of containment devices, facilities, and protective barriers is necessary. Training and education about the epidemiology, pathogenicity, and biohazards of the microorganisms involved may prevent or decrease the risk. In this way, the scientific community may benefit from the lessons learned in the past to anticipate future problems.
A rapid switch from hyperbolic to isokinetic cycling allows the velocity-specific decline in maximal power to be measured, i.e., fatigue. We reasoned that, should the baseline relationship between isokinetic power (Piso) and electromyography (EMG) be reproducible, then contributions to fatigue may be isolated from 1) the decline in muscle activation (muscle activation fatigue); and 2) the decline in Piso at a given activation (muscle fatigue). We hypothesized that the EMG-Piso relationship is linear, velocity dependent, and reliable for instantaneous fatigue assessment at intolerance during and following whole body exercise. Healthy participants (n = 13) completed short (5 s) variable-effort isokinetic bouts at 50, 70, and 100 rpm to characterize baseline EMG-Piso. Repeated ramp incremental exercise tests were terminated with maximal isokinetic cycling (5 s) at 70 rpm. Individual baseline EMG-Piso relationships were linear (r(2) = 0.95 ± 0.04) and velocity dependent (analysis of covariance). Piso at intolerance (two legs, 335 ± 88 W) was ∼45% less than baseline [630 ± 156 W, confidence interval of the difference (CIDifference) 211, 380 W, P < 0.05]. Following intolerance, Piso recovered rapidly (F = 44.1; P < 0.05; η(2) = 0.79): power was reduced (P < 0.05) vs. baseline only at 0-min (CIDifference 80, 201 W) and 1-min recovery (CIDifference 13, 80 W). Activation fatigue and muscle fatigue (one leg) were 97 ± 55 and 60 ± 50 W, respectively. Mean bias ± limits of agreement for reproducibility were as follows: baseline Piso 1 ± 30 W; Piso at 0-min recovery 3 ± 35 W; and EMG at Piso 3 ± 14%. EMG power is linear, velocity dependent, and reproducible. Deviation from this relationship at the limit of tolerance can quantify the "activation" and "muscle" related components of fatigue during cycling.
is caused by the severe acute Respiratory syndrome coronavirus-2 (SARS-CoV-2), which has become unstoppable, spreading rapidly worldwide and, consequently, reaching a pandemic level. This review aims to provide the information available so far on the likely animal origin of SARS-CoV-2 and its possible hosts/reservoirs as well as all natural animal infections and experimental evidence using animal models. Horseshoe bats from the species Rhinolophus affinis seem to be a natural reservoir and pangolins (Manis javanica) appear to be an intermediate host of SARS-CoV-2. Humans remain the most likely spreading source of SARS-CoV-2 to other humans and also to domestic, zoo and farm animals. Indeed, human-to-animal transmission has been reported in cats, dogs, tigers, lions, a puma and minks. Animal-to-human transmission is not a sustained pathway, although mink-to-human transmission remains to be elucidated. Through experimental infections, other animals seem also to be susceptible hosts for SARS-CoV-2, namely ferrets, some non-human primate species, hamsters and transgenic mice, while dogs, pigs and poultry are resistant. A One Health perspective must be implemented in order to develop epidemiological surveillance and establish disease control mechanisms to limit zoonotic transmission. Moreover, research in this field is important to better understand SARS-CoV-2 and to obtain the long-awaited vaccine and specific treatment.
Forty Candida albicans strains isolated from patient's mouth with fixed orthodontic appliances were analyzed to their susceptibilities to antifungal agents, mouth rinses and essential oils. Susceptibility to fluconazole, econazole, miconazole and ketoconazole, amphotericin B and nystatin was assessed by the disk diffusion (DD) method based on the Clinical and Laboratory Standards Institute M44-A protocol, and by Etest (fluconazole and amphotericin B). The susceptibilities to mouth rinses and essential oils were also determined by the DD technique. All isolates tested were susceptible (S) to amphotericin B, nystatin and fluconazole. The overall concordance between the DD and the Etest was 100% for amphotericin and fluconazole. One isolate was resistant to econazole (2.5%) and the other to ketoconazole (2.5%). Econazole and ketoconazole had the highest percentages of susceptible dose dependent (SDD), 55 and 95%, respectively. Regarding to the susceptibility isolates profile, seven phenotypes were detected, and the 3 more represented (90% of the isolates) of them were SDD to one, two or three azoles. The study of mouth rinses showed a high variability of efficacy against C. albicans. The results showed that the isolates susceptibility to essential oils differed (P \ 0.05). The profile activity was: cinnamon [ laurel [ mint [ eucalyptus [ rosemary [ lemon [ myrrh [ tangerine. The main finding was that the susceptibility to cinnamon and laurel varied among the three more representative antifungal phenotypes (P \ 0.05). The susceptibility of econazole-SDD isolates to cinnamon and lemon was higher than those of the econazole-S yeasts (P \ 0.05). In contrast, econazole-SDD isolates were less affected by laurel than econazole-S counterparts (P \ 0.05).
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