Laura Peeters

Susceptibility of Avian Pathogenic Escherichia coli from Laying Hens in Belgium to Antibiotics and Disinfectants and Integron Prevalence

SUMMARY Avian pathogenic Escherichia coli (APEC) causes huge annual losses in the poultry industry worldwide. Multiresistance against antibiotics of APEC strains is increasingly seen in broilers, although much is still unknown about strains from laying hens where use of antibiotics is limited. Disinfection can reduce the infection burden. However, little is known about the presence of resistance against these products. Ninety-seven APEC strains were isolated from Belgian laying hens. The resistance to different classes of antibiotics was determined as well as the minimum inhibitory concentrations (MIC; agar and broth dilution) and minimum bactericidal concentrations (MBC) of five disinfectants most often used in the poultry industry (formaldehyde, glutaraldehyde, glyoxal, hydrogen peroxide, and a quaternary ammonium compound). The presence of integrons was determined by PCR. Resistance to ampicillin (35.1%), nalidixic acid (38.1%), sulfonamides (SULFA, 41.2%), and tetracycline (TET, 53.6%) was high but resistance to other tested antibiotics was low. Nevertheless, two extended spectrum beta-lactamase producers were found. The MIC of the disinfectants for the APEC strains showed a Gaussian distribution, indicating that there was no acquired resistance. MBCs were similar to MICs via the broth dilution method, showing the bactericidal effect of the disinfectants. Twenty-one strains (21.6%) were found positive for class 1 integrons and a positive association between integron presence and resistance to trimethoprim, SULFA, and TET was found. No association could be found between integron presence and phylogenetic group affiliation. Susceptibility of APEC strains from laying hens to antibiotics is, in general, very high. Phenotypic resistance to commonly used disinfectants could not be found, indicating that the current use of disinfectants in the laying hen industry did not select for resistance. RESUMEN Susceptibilidad a los antibióticos, desinfectantes y prevalencia de integrones de Escherichia coli patógena aviar de aves de postura en Bélgica. La Escherichia coli patógena aviar (con las siglas en inglés APEC) causa enormes pérdidas anuales en la industria avícola de todo el mundo. La resistencia múltiple a los antibióticos por las cepas de E. coli patógenas aviares se observa cada vez más en los pollos de engorde, aunque queda mucho por conocer sobre las cepas de gallinas ponedoras donde el uso de antibióticos es limitado. La desinfección puede reducir la carga de la infección. Sin embargo, poco se sabe acerca de la presencia de resistencia en contra de estos productos. Noventa y siete cepas de E. coli patógenas aviares fueron aisladas de gallinas ponedoras en Bélgica. La resistencia a las diferentes clases de antibióticos se determinó así como las concentraciones mínimas inhibitorias (CMI; con diluciones en agar y en caldo) y las concentraciones mínimas bactericidas (MBC) de cinco desinfectantes que se utilizan más a menudo en la industria avícola (formaldehído, glutaraldehído, glioxal, peróxido de hidrógeno y un compuesto cuaternario de amonio). La presencia de integrones se determinó mediante PCR. La resistencia a la ampicilina (35.1%), ácido nalidíxico (38.1%), sulfonamidas (SULFA, 41.2%) y tetraciclina (TET, 53.6%) fueron altas, pero la resistencia a otros antibióticos analizados fue baja. Sin embargo, se encontraron dos productores de beta-lactamasas de espectro extendido. La concentración mínima inhibitoria de los desinfectantes para las cepas de E. coli patógenas aviares mostró una distribución de Gauss, lo que indica que no había resistencia adquirida. Las concentraciones mínimas bactericidas fueron similares a las concentraciones mínimas inhibitorias a través del método de dilución en caldo, que muestra el efecto bactericida de los desinfectantes. Veintiún cepas (21.6%) resultaron positivas para la clase 1 de integrones y se encontró una asociación positiva entre la presencia de integrones y la resistencia a la trimetoprima, sulfonamidas, y TET. Ninguna asociación se pudo encontrar entre la presencia de integrones y la pertenencia a un grupo filogenético. La susceptibilidad a los antibióticos mostrada por las cepas de E. coli patógenas aviares de gallinas ponedoras es en general muy alta. La resistencia fenotípica a los desinfectantes de uso común no se pudo encontrar, lo que indica que el uso actual de los desinfectantes en la industria de la gallina ponedora no seleccionó para resistencia.

Antimicrobial resistance and population structure of Staphylococcus aureus recovered from pigs farms.

Staphylococcus aureus is a burden in human and veterinary medicine. During the last decade, an increasing number of studies reported the presence of livestock-associated methicillin-resistant S. aureus (LA-MRSA) clonal complex (CC) 398 in pigs. During 2013, a survey was performed in pig farms (n=328) randomly selected over Belgium, to monitor the current epidemiological situation of LA-MRSA among asymptomatic pigs and compare with former data to determine possible evolutions. Per farm, nose swabs were taken from 20 animals and pooled. MRSA was detected in 215 farms. Most isolates belonged to CC398 (n=211), and the remaining were ST9/t337 (n=1), ST80/t044 (n=2) and ST239/t4150 (n=1). A large diversity (n=19) of spa-types was found in the CC398 isolates. More than 90% of the isolates were non-wild type (NWT) to tetracycline and trimethoprim. NWT isolates were also found for ciprofloxacin (61.1%), clindamycin (64.4%), erythromycin (57.8%), kanamycin (43.1%) and gentamicin (45.5%). Microarray analysis showed that most CC398 isolates carried genes encoding resistance to tetracycline [tet(M)], macrolide-lincosamide-streptogramin group [erm(B), erm(C), lnu(A), vga(A)], aminoglycosides (aacA-aphD,aa dD, aphA3, sat) and/or phenicols (fexA). One CC398 isolate carried the multi-resistance gene cfr. The non-CC398 isolates carried virulence genes, as the egc-like cluster. The ST80 strain carried the Panton-Valentine leukocidin gene and corresponded to the community-acquired (CA-)MRSA ST80-IV European clone. The MRSA prevalence among pigs in Belgium remains similar to previous studies but a larger diversity in spa-types has been detected in this study. The recovery of CA-MRSA from livestock indicates that one should remain vigilant to the evolution of LA-MRSA in pigs.

Effect of residual doxycycline concentrations on resistance selection and transfer in porcine commensal Escherichia coli

Pig feed may contain various levels of antimicrobial residues due to cross-contamination. A previous study showed that a 3% carry-over level of doxycycline (DOX) in the feed results in porcine faecal concentrations of approximately 4 mg/L. The aim of this study was to determine the effect of residual DOX concentrations (1 and 4 mg/L) in vitro on selection of DOX-resistant porcine commensal Escherichia coli and transfer of their resistance plasmids. Three different DOX-resistant porcine commensal E. coli strains and their plasmids were characterised. These strains were each brought in competition with a susceptible strain in a medium containing 0, 1 and 4 mg/L DOX. Resistant bacteria, susceptible bacteria and transconjugants were enumerated after 24 h and 48 h. The tet(A)-carrying plasmids showed genetic backbones that are also present among human E. coli isolates. Ratios of resistant to susceptible bacteria were significantly higher at 1 and 4 mg/L DOX compared with the blank control, but there was no significant difference between 1 and 4 mg/L. Plasmid transfer frequencies were affected by 1 or 4 mg/L DOX in the medium for only one of the resistance plasmids. In conclusion, DOX concentrations of 1 and 4 mg/L can select for resistant E. coli in vitro. Further research is needed to determine the effect of these concentrations in the complex environment of the porcine intestinal microbiota.

Selection and transfer of an IncI1‐tet(A) plasmid of Escherichia coli in an ex vivo model of the porcine caecum at doxycycline concentrations caused by crosscontaminated feed

The aim of this study was to investigate the effect of subtherapeutic intestinal doxycycline (DOX) concentrations (4 and 1 mg l−1), caused by cross‐contamination of feed, on the enrichment of a DOX‐resistant commensal Escherichia coli and its resistance plasmid in an ex vivo model of the porcine caecum.

Establishing Sexual Assault Care Centres in Belgium: health professionals’ role in the patient-centred care for victims of sexual violence

BackgroundHaving ratified the Convention of Istanbul, the Belgian federal government commits itself to the foundation of Sexual Assault Care Centres (SACC). In the light of researching the feasibility of these centres, this study aimed to evaluate the care for victims of sexual violence (SV) in Belgian hospitals anno 2016 as well as to formulate recommendations for the intended model.MethodsBetween April and October 2016, a questionnaire was distributed to 159 key health professionals active in 17 different hospitals attached to an AIDS Referral Centre. The survey covered four parts, i.e. the health professionals’ profile, their knowledge, attitude and practices, an assessment of the hospital’s policy and the caregivers’ opinion on the care for victims of SV and on the intended SACCs. Subsequently, a descriptive analysis using ‘IBM SPSS Statistics 23’ was performed.ResultsA total of 60 key health professionals representing 15 different hospitals completed the questionnaire resulting in a response rate of 38%. The results showed a lack of knowledge and practical experience of caregivers’ regarding the care for SV victims. Approximately 30% of responders face personal or professional difficulties upon provision of care to victims of SV. Participants evaluate the current care as good, despite the limited psychosocial support, follow-up, insight for the needs of vulnerable groups and support for family, relatives and health professionals. Yet, the majority of health professionals appraise the SACCs as the best approach for both victims and caregivers.ConclusionsBy introducing a SACC, the Belgian federal government aims to provide holistic and patient-centred care for victims of SV. Essential in patient-centred health care is an extensive and continuous education, training and supervision of health professionals concerning the care for victims, support for family, relatives and caregivers.At the end and as a result of a participatory process with many professional experts as well as victims, a specific Belgian model, adjusted to the health care system anno 2016 was developed for piloting. The main challenges in establishing SACCs are situated at the institutional and policy level. Collaborating with other institutions and further research are herewith required.