Antimicrobial prophylaxis in companion animal surgery: A scoping review for European Network for Optimization of Antimicrobial Therapy (ENOVAT) guidelines.

Surgical antimicrobial prophylaxis (SAP) is widely used to reduce the risk of surgical site infections (SSI), but there is uncertainty as to what the proportion of SSI reduction is. Therefore, it is difficult for surgeons to properly weigh the costs, risks and benefits for individual patients when deciding on the use of SAP, making it challenging to promote antimicrobial stewardship in primary practice settings. The objective of this study was to map the veterinary evidence focused on assessing the effect of SAP on SSI development and in order to identify surgical procedures with some research evidence and possible knowledge gaps. In October 2021 and December 2022, Scopus, CAB Abstracts, Web of Science Core Collection, Embase and MEDLINE were systematically searched. Double blinded screening of records was performed to identify studies in companion animals that reported on the use of SAP and SSI rates. Comparative data were available from 34 out of 39123 records screened including: eight randomised controlled trials (RCT), 23 cohort studies (seven prospective and 16 retrospective) and three retrospective case series representing 12476 dogs and cats in total. Extracted data described peri- or post-operative SAP in nine, and 25 studies, respectively. In the eight RCTs evaluating SAP in companion animals, surgical procedure coverage was skewed towards orthopaedic stifle surgeries in referral settings and there was large variation in SAP protocols, SSI definitions and follow-up periods. More standardized data collection and agreement of SSI definitions is needed to build stronger evidence for optimized patient care.

The interaction of a thiosemicarbazone derived from R - (+) - limonene with lipid membranes.

As a potential drug, 2-nitrobenzaldehyde-thiosemicarbazone (2-TSC), a thiosemicarbazone derived from the terpene R-(+)-limonene, was studied through calorimetric and spectroscopic techniques. Differential Scanning Calorimetry (DSC) data showed that 2-TSC causes structural changes in a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DMPC) membrane, strongly decreasing the cooperativity of the bilayer gel-fluid thermal transition. Optical absorption spectroscopy showed that 2-TSC is more soluble in ethanol and lipids than in water medium, and that the drug displays different structures in the different environments. Though 2-TSC displays no fluorescence, time resolved fluorescence showed that the drug is an effective quencher of the fluorescent probe 6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan). As it is well accepted that Laurdan is positioned into the bilayer close to the membrane surface, that is possibly the localization of 2-TSC in a bilayer. Electron spin resonance (ESR) of the probe 1-palmitoyl-2-stearoyl-(14-doxyl)-sn-glycero-3-phosphocholine (14-PCSL) revealed that 2-TSC is inserted into the hydrocarbon part of the bilayer, fluidizing the lipid bilayer gel phase and rigidifying or organizing the bilayer fluid phase. Similar effects are found for other lipophilic molecules, including cholesterol. These results are useful to improve the understanding of the processes that govern the interaction of thiosemicarbazones with cell membranes, related to the activity of the drugs and their cytotoxicity.

Challenges in the rabbit haemorrhagic disease 2 (RHDV2) molecular diagnosis of vaccinated rabbits.

Molecular methods are fundamental tools for the diagnosis of viral infections. While interpretation of results is straightforward for unvaccinated animals, where positivity represents ongoing or past infections, the presence of vaccine virus in the tissues of recently vaccinated animals may mislead diagnosis. In this study, we investigated the interference of RHDV2 vaccination in the results of a RT-qPCR for RHDV2 detection, and possible associations between mean Cq values of five animal groups differing in age, vaccination status and origin (domestic/wild). Viral sequences from vaccinated rabbits that died of RHDV2 infection (n=14) were compared with the sequences from the commercial vaccines used in those animals. Group Cq means were compared through Independent t-test and One-way ANOVA. We proved that RHDV2 vaccine-RNA is not detected by the RT-qPCR as early as 15days post-vaccination, an important fact in assisting results interpretation for diagnosis. Cq values of vaccinated and non-vaccinated infected domestic adults showed a statistically significant difference (p<0.05), demonstrating that vaccination-induced immunity reduces viral loads and delays disease progression. Contrarily, in vaccinated young rabbits higher viral loads were registered compared to non-vaccinated kittens. No significant variation (p=0.3824) was observed between viral loads of non-vaccinated domestic and wild RHDV2-victimised rabbits. Although the reduced number of vaccinated young animals analysed hampered a robust statistical analysis, this occurrence suggests that passively acquired maternal antibodies may inhibit the active immune response to vaccination, delaying protection and favouring disease progression. Our finding emphasises the importance of adapting kitten RHDV2 vaccination schedules to circumvent this interference phenomenon.

Tularaemia: a challenging zoonosis.

In recent years, several emerging zoonotic vector-borne infections with potential impact on human health have been identified in Europe, including tularaemia, caused by Francisella tularensis. This remarkable pathogen, one of the most virulent microorganisms currently known, has been detected in increasingly new settings and in a wide range of wild species, including lagomorphs, rodents, carnivores, fish and invertebrate arthropods. Also, a renewed concern has arisen with regard to F. tularensis: its potential use by bioterrorists. Based on the information published concerning the latest outbreaks, the aim of this paper is to review the main features of the agent, its biology, immunology and epidemiology. Moreover, special focus will be given to zoonotic aspects of the disease, as tularaemia outbreaks in human populations have been frequently associated with disease in animals.

Tuberculosis diagnosis after bleach processing for early stage tuberculosis laboratory capacity building.

The diagnosis of tuberculosis is seriously hampered in the absence of standard biosafety laboratory facilities for specimen concentration and Mycobacterium tuberculosis culture. Within a laboratory twinning arrangement, heat-fixed direct smear and sediment from 74 bleach-processed and 20 non-processed specimens from Cumura Hospital, Guinea-Bissau, were sent to Lisbon for molecular evaluation of rifampicin resistance. Sequence analysis of a 369 base-pair rpoB locus detected 3.2% (3/94) resistant specimens. To our knowledge, this represents the first report on the molecular analysis of M. tuberculosis from bleach-processed sputum, an alternative to current diagnostic practice in low-resource settings.

Bridging the gap between PCR detection of Mycobacterium tuberculosis complex and tuberculosis diagnosis.

The growing demand for rapid diagnosis of tuberculosis (TB) has led to the incorporation of nucleic acid amplification (NAA) tests in case definitions. The objective of this study was to evaluate the contribution of a real-time polymerase chain reaction (PCR) assay in providing a result predictive of a confirmed TB case. Respiratory and extra-pulmonary specimens (n = 308) were subjected to NAA, culture and smear microscopy. Qualitative PCR assessment, translated by an increase in NAA cycles, disregarding template copy number, resulted in an increase in confirmed cases, helping to bridge the gap between the test's analytical performance and its actual performance in TB diagnosis.

MIRU-VNTR typing adds discriminatory value to groups of Mycobacterium bovis and Mycobacterium caprae strains defined by spoligotyping.

The value of Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeats (MIRU-VNTR) as a genotyping technique for Mycobacterium bovis and Mycobacterium caprae, has been confirmed in different countries and epidemiological scenarios. However, a standardized panel of loci has not yet been adopted for these species, since allelic diversity of each locus differs among countries. To determine the most discriminatory loci, a panel of 181 M. bovis and M. caprae strains representing 12 spoligotypes was created. The panel included strains from the three predominant spoligotypes previously isolated in Portugal; strains from spoligotyping group SB0140, prevalent in the British Isles but also detected in Portugal; strains from spoligotypes common to cattle and wildlife species and strains from the M. caprae spoligotyping group SB0157. MIRU-VNTR analysis of these strains, targeting 8 selected loci, produced 87 different profiles (h=0.99), being VNTR3232, QUB11a, ETR-B and ETR-A the most discriminatory loci (h=0.96). A single M. bovis spoligotyping group could be differentiated - up to 44 MIRU-VNTR profiles. These results emphasize the high genotype diversity of Portuguese isolates compared with other countries. MIRU-VNTR typing was superior to spoligotyping for identifying multi-genotype infected herds and the combination of the two genotyping methods by a hierarchical approach confirmed the genetic relatedness of M. bovis isolates between cattle and wildlife.

Spoligotype diversity of Mycobacterium bovis and Mycobacterium caprae animal isolates.

The genetic diversity of 283 Mycobacterium bovis (M. bovis) and 10 Mycobacterium caprae (M. caprae) strains, isolated between 2002 and 2007 from cattle, goat, red deer and wild boar from six different geographical regions of Portugal was investigated by spoligotyping. The technique showed a good discriminatory power (Hunter-Gaston Index, h=0.9) for the strains, revealing 29 different patterns. One pattern (SB0121) was clearly predominant, accounting for 26.3% of the isolates; ten patterns, representing 20.7% of the isolates, had never been reported previously. Multiple spoligotypes were detected in thirteen cattle and one goat herd, most of which were found in beef cattle and extensive management regions, suggesting different infection sources. With the exception of two spoligotypes, those in wildlife species were also found in domestic species.