The dynamic of antibiotic resistance in commensal Escherichia coli throughout the growing period in broiler chickens: fast-growing vs. slow-growing breeds.

Antimicrobial resistance (AMR) is an important threat to public health worldwide. Furthermore, different studies have demonstrated a close association between antibiotic use in animal production and AMR in humans. It is well known that it is necessary to reduce antibiotic administration in farms by finding effective alternative treatments, using more resistant breeds and improving animal welfare. However, to be able to assess the alternatives proposed, it is essential to study the epidemiology of AMR under production conditions. Hence, the aim of this study was to investigate the AMR dynamic in 2 genetic poultry breeds during the growing period. The study was performed in 2 experimental poultry houses to simulate real production conditions, and no antibiotics were administered during the growing period. In addition, 2 poultry breeds were used, fast-growing and slow-growing. To evaluate AMR evolution, Escherichia coli was selected as indicator bacterium. To this end, animals from each experimental group were sampled at different times: on day of arrival, at mid-period, and at slaughter day. In the laboratory, cecal content was removed and inoculated in selective media. Then, biochemical tests were performed to confirm E. coli. Finally, antibiotic susceptibility was assessed according to Decision 2013/653. At the onset of the cycle, significant differences were observed between breeds, as the E. coli strains isolated from fast-growing 1-day-old-chicks showed higher AMR rates. However, at the end of the period, no significant differences were found between breeds and their presence of resistant bacteria (above 95%). Therefore, although no antibiotics were administered during the growing period, a high level of AMR at slaughter day was demonstrated. Further studies are necessary to determine the main risk factors that increase the level of AMR throughout the productive cycle in broiler chickens. In conclusion, it is important to highlight that although it is crucial to control both antibiotic use and animal welfare during the growing period, measures should be taken at all levels of the production chain.

Drug-resistant Neisseria gonorrhoeae: latest developments.

Gonorrhea is the second most frequently reported notifiable disease in the United States and is becoming increasingly common in Europe. The purpose of this review was to assess the current state of drug-resistant Neisseria gonorrhoeae in order to evaluate future prospects for its treatment. An exhaustive literature search was conducted to include the latest research regarding drug resistance and treatment guidelines for gonorrhea. Gonococci have acquired all known resistance mechanisms to all antimicrobials used for treatment. Currently, the European Union, the United States, and the United Kingdom have established surveillance programs to assess, on a yearly basis, the development of gonococcal resistance. Current treatment guidelines are being threatened by the increasing number of ceftriaxone-, cefixime-, and azithromycin-resistant N. gonorrhoeae strains being detected worldwide. This has led the scientific community to develop new treatment options with new molecules in order to persevere in the battle against this "superbug".

Detection of hepatitis E virus (HEV) through the different stages of pig manure composting plants.

Hepatitis E virus (HEV) is an increasing cause of acute hepatitis in industrialized countries. The aim of this study was to evaluate the presence of HEV in pig manure composting plants located in Spain. For this purpose, a total of 594 samples were taken in 54 sampling sessions from the different stages of composting treatment in these plants as follows: slurry reception ponds, anaerobic ponds, aerobic ponds, fermentation zone and composting final products. HEV was detected by reverse transcription polymerase chain reaction (RT-nested PCR) in four (80%) of five plants studied, mainly in the first stages of the process. HEV was not detected in any final product (compost) sample, destined to be commercialized as a soil fertilizer, suggesting that composting is a suitable method to eliminate HEV and thus, to reduce the transmission of HEV from pigs to humans.

Using digital photography to implement the McFarland method.

The McFarland method allows the concentration of bacterial cells in a liquid medium to be determined by either of two instrumental techniques: turbidimetry or nephelometry. The microbes act by absorbing and scattering incident light, so the absorbance (turbidimetry) or light intensity (nephelometry) measured is directly proportional to their concentration in the medium. In this work, we developed a new analytical imaging method for determining the concentration of bacterial cells in liquid media. Digital images of a series of McFarland standards are used to assign turbidity-based colour values with the aid of dedicated software. Such values are proportional to bacterial concentrations, which allow a calibration curve to be readily constructed. This paper assesses the calibration reproducibility of an intra-laboratory study and compares the turbidimetric and nephelometric results with those provided by the proposed method, which is relatively simple and affordable; in fact, it can be implemented with a digital camera and the public domain software ImageJ.

[Progressive multifocal leukoencephalopathy in the province of Cadiz, Spain]. / Leucoencefalopatía multifocal progresiva en la provincia de Cádiz, España.

INTRODUCTION: Progressive multifocal leukoencephalopathy (PML), which is caused by the reactivation of an infection due to the JC human polyoma virus, affects immunocompromised patients and more especially those infected by the human immunodeficiency virus. It produces a multifocal neurological clinical picture due to the destruction of oligodendrocytes and the subsequent demyelination. AIMS: To analyse the epidemiological, semiological and radiological characteristics of a sample of patients diagnosed with PML in the province of Cadiz, and to study their rates of survival. PATIENTS AND METHODS: Our sample consisted of 23 patients with PML who presented an unfavourable immunological situation and deficient therapeutic compliance. Factors studied included time to progression of the symptoms, clinical features, neuroimaging and survival. RESULTS: The mean time elapsed between the appearance of symptoms and diagnosis was 30 days. There was a wide range of manifestations: motor symptoms were the most prevalent and cognitive compromise was far less common. All the patients submitted to magnetic resonance imaging of the head and only eight of those who underwent computerised axial tomography displayed multiple insults. The mean survival time was 60 days in the case of the seven deaths and over two years in those who survived. CONCLUSIONS: The symptoms of the patients were similar to those reported in the literature, except for the absence of dementia. Magnetic resonance imaging was better than tomography at detecting multiple, dispersed insults and is more cost-effective for diagnosing PML. The survival time of most of the patients was higher than that reported in previous studies.

High prevalence of Blastocystis sp. in pigs reared under intensive growing systems: frequency of ribotypes and associated risk factors.

Three hundred and ninety-five pig fecal samples were analyzed looking for Blastocystis sp. using optical microscopy and PCR. A global prevalence of 46.8% has been observed in this study, although relative values of prevalence differ notably according to the strata examined, ranging from 9.3% in sows to 75% in weaners. Statistic analysis of the data included several risk factors such as different management systems, date of sample collection, fecal consistency, age and sex of the animals. The presence of the parasite was statistically associated to the variables "age" and "date of sample collection", being more prevalent in weaners and grower pigs and warm season. Random fragment-length polymorphism (RFLP-PCR) analysis of positive PCR samples revealed a high homology in the digestion pattern, appearing as two ribotypes. The results were further confirmed by sequencing of ten randomly selected samples, showing that the samples obtained in this study were included in two genotypes: genotype I previously named by Noël et al. [Noël, C., Dufernez, F., Gerbod, D., Edgcomb, V.P., Delgado-Viscogliosi, P., Ho, L.-Ch., Singh, M., Wintjens, R., Sogin, M.L., Capron, M., Pierce, R., Zenner, L., Viscogliosi, E., 2005. Molecular phylogenies of Blastocystis isolates from different hosts: implications for genetic diversity, identification of species, and zoonosis. J. Clin. Microbiol. 43, 348-355], in which Blastocystis sp. sequences from humans, pigs and cattle were included, and genotype II, which only included Blastocystis hominis sequences obtained from human and other primates. This is the first report including Blastocystis sequences from swine origin in genotype II.

Detection of hepatitis E virus in patients sera in southern Spain.

The aim of the present study was to detect acute Hepatitis E virus (HEV) infection in patients with abnormal alanine transaminase (ALT) in which other viral hepatitis infections had been excluded in southern Spain, an area adjacent to regions where this disease is endemic. Of 336 sera tested 30 (8.92%) were positive for IgM antibodies against HEV (anti-HEV IgM) and 7 (2.08%) were negative in a repeated assay. Immunoblot analysis (IBA) was applied to the 37 positive sera in the first assay; its results were positivity for 26 (7.73%), ambiguous for 5 and negative for 6 sera. Amplification of ORF1 and ORF2 of HEV by means of nested RT-PCR was carried out with the 37 sera that were either positive or ambiguous by ELISA; a positive result was obtained only with one serum for the ORF2 protein. IgM antibodies against the HEV ORF2 protein could be a useful marker in the diagnosis of acute infection and a substitute for the determination of viral RNA in serum; this is of both diagnostic and epidemiological importance as it would allow the patients transmitting the infection to be recognized by means of a simple determination of antibodies. The sequence of the ORF2 fragment of HEV occurring in samples taken from both humans and animals amplified in this study has considerable homology with the sequences of HEV strains/isolates of European origin. These results demonstrate that an autochthonous HEV circulates in Spain.

A 3-year follow-up of HCV-RNA viraemia in haemodialysis patients.

BACKGROUND: Hepatitis C virus (HCV) infection in a population of haemodialysed patients was studied over a 3-year follow-up period in order to evaluate the changes in viral RNA, diversity of genotypes, and serological response to synthetic HCV peptides. METHODS: Twenty-eight (32.9%) patients with anti-HCV antibodies from a total of 85 patients assigned to a haemodialysis unit were studied. The serological response to immunopeptides was evaluated by immunoblotting, viral RNA in serum was detected using the polymerase chain reaction (RT-PCR), and genotyping was carried out by hybridization with probes fixed to nitrocellulose paper. RESULTS: Of the 28 haemodialysis patients who had anti-HCV antibodies, three (10.7%) were always RNA negative, six (21.4%) were always RNA positive, and 19 (67.8%) were variable RNA. There was an incomplete antibody response to non structural antigens in non-viraemic patients. Genotype was determined in 23 patients, and the other two could not be genotyped. The most common genotype was 1b (69.4%), followed by 1a (17.4%), and 2a, 3a, and 4a (each 4.4%). CONCLUSIONS: Haemodialysis patients, when followed up for a long time, frequently show an intermittent HCV viraemia state, suggesting that HCV cannot be evaluated adequately by isolated RNA determinations.