Changes in Surgical Volume in Military Medical Treatment Facilities and Military Surgeon Clinical Combat Readiness During the COVID-19 Pandemic.

Mini-abstract In this retrospective study, we evaluated changes in measures of surgeon clinical combat readiness within the military health system during the COVID-19 pandemic. We found a 36% reduction in surgical knowledge and skills as compared to pre-COVID. Sizable reductions were encountered for surgery for colectomy (-50%) and aneurysm repair (-61%).

Rat bite fever.

Rat bite fever (RBF) is a bacterial zoonosis for which two causal bacterial species have been identified: Streptobacillis moniliformis and Spirillum minus. Haverhill fever (HF) is a form of S. moniliformis infection believed to develop after ingestion of contaminated food or water. Here the infectious agents, their host species, pathogenicity (virulence factors and host susceptibility), diagnostic methods, therapy, epidemiology, transmission and prevention are described. Special emphasis is given on information from the field of laboratory animal microbiology and suggestions for future research.

The introduction of Arcobacter spp. in poultry slaughterhouses.

Despite the presence high levels of Arcobacter spp. on chicken carcasses, the source of arcobacter contamination in slaughterhouses still remains unclear. It has been hypothesised in the literature that Arcobacter species that contaminate carcasses originate in in-plant slaughterhouses and/or supply water. The present study aimed to determine the source of Arcobacter contamination in two poultry slaughterhouses in The Netherlands. Carcasses and intestinal tracts from 3 hen flocks and 2 broiler flocks were collected. Water draining off carcasses during processing in 2 slaughterhouses and supply water in one slaughterhouse were also taken. For one flock, cloacal swabs and faecal samples were taken on the farm before slaughtering. ERIC-PCR was applied to study the genetic diversity and relationship among the isolates. No Arcobacter spp. were found in the supply water but on almost all of the sampled carcasses and in carcass-draining-off water arcobacters were identified. Arcobacter spp. were detected in the gut systems of chickens, ranging from 20% to 85% in hens and 3.3% and 51% in broilers. Similar ERIC-PCR genotypes were detected in gut contents as well as on carcasses from the same flock. The present study demonstrated that Arcobacter spp. can be detected in chicken intestines at slaughter and could be brought in this way into slaughterhouses where the bacteria contaminate carcasses during processing.

Arcobacter spp. possess two very short flagellins of which FlaA is essential for motility.

Like Campylobacter and Helicobacter spp., Arcobacter spp. possess two flagellin genes (flaA and flaB) located adjacent to each other. The aim of this study was to characterize the flagellin proteins of Arcobacter spp., because these proteins are known virulence factors in the Epsilonproteobacteria, to which these three species belong. With the exception of Arcobacter nitrofigilis, Arcobacter flagellins are almost half the size of those in other Epsilonproteobacteria. Arcobacter flagellin proteins lack a large part of the variable central region. The low homology observed among flagellins of different Arcobacter species indicates genetic heterology between the members of this genus. Unlike in other Epsilonproteobacteria, the transcription of flagellin genes is not regulated by sigma 28- or sigma 54-dependent promoters, which suggests that transcription must be regulated in a different way in Arcobacter spp. Mutational studies revealed that only FlaA is needed for the motility of Arcobacter spp. Quantitative PCR analysis showed that transcription of flaB is higher at 30 degrees C than at 37 degrees C. Mutation of flaB had no effect on motility or on flaA transcription while mutation of flaA abolished motility and increased the transcription of flaB. These results underline that the genus Arcobacter is an unusual taxon in the epsilon subdivision of the Proteobacteria.

Dogs as vectors of Streptobacillus moniliformis infection?

Rat bite fever is a bacterial zoonosis transmitted through the bite of rats. One of the two etiological agents that cause rat bite fever is Streptobacillus moniliformis. Rat bite fever is rare and very likely under diagnosed but occurs worldwide. Other animals, like dogs and cats that have mouthed a rat are often mentioned in the literature as potential risks for the attraction of rat bite fever. However, rat bite fever caused by the bite of a dog or cat has very seldom been documented. Therefore, to identify the possible risk for humans to become infected with S. moniliformis after having been bitten by a dog that has been in contact with rats, the presence of S. moniliformis in the mouth of these dogs was tested with molecular methods. Swabs taken from the mouth of 18 dogs with proven contacts with rats were tested for the presence of S. moniliformis DNA by PCR. An amplicon of the right size was obtained in 10 of the 18 dogs. Nucleotide sequencing of five amplicons of PCR positive samples demonstrated the presence of S. moniliformis DNA in the mouth of three dogs. A bite by these dogs therefore might infect humans with S. moniliformis and cause rat bite disease.

Interaction of Arcobacter spp. with human and porcine intestinal epithelial cells.

Little is known about the pathogenic mechanisms or potential virulence factors of Arcobacter spp. The aim of the study described here was to obtain more insights in the pathogenicity mechanisms of Arcobacter spp. by testing their ability to adhere to, invade and induce interleukin-8 expression in human Caco-2 and porcine IPI-2I cell lines. Eight Arcobacter strains were tested. Four strains were obtained from a culture collection, and represent the four Arcobacter spp. known to be associated with animals and humans. The other four strains were field isolates from the amniotic fluid of sows and from newborn piglets. All eight Arcobacter strains were able to adhere to both cell lines, and induced interleukin-8 production as early as 2 h after a 1h incubation period. This production was still increased 6 h postinfection. Differences in the cell association of the eight strains were obvious, with A. cibarius showing the highest adhesion ability. Invasion of intestinal epithelial cells was only observed for A. cryaerophilus strains. No correlation between invasiveness or strong adhesion of the tested strains and the level of interleukin-8 induction was observed.

Arcobacter, what is known and unknown about a potential foodborne zoonotic agent!

Since the introduction of the genus Arcobacter in 1991, the association of Arcobacter butzleri, Arcobacter cryaerophilus and Arcobacter skirrowii with humans and animals has been clearly established. These bacteria have been detected world wide in products of animal origin and in healthy animals as well as in surface water. A fourth species Arcobacter cibarius was recently discovered on chicken carcasses. Although evidence was found for the connection of Arcobacter spp. with human and animal illness, Arcobacter spp. can be pathogens, opportunistic pathogens and commensals. Their potential as zoonotic foodborne and waterborne agents, the routes of transmission and the pathogenic mechanisms of these bacteria are largely unknown. Production of toxins or other virulence factors has not been demonstrated but adhesive and/or invasive properties were apparent. Antibiotic resistance is present in Arcobacter strains to significant levels. The tools to genetically access Arcobacter-like transformation of strains, construction of mutants are not yet available. Nor have genes (i.e. potential virulence factors) been cloned, expressed and characterized in other host organisms. Therefore those interested in the microbiology of these organisms eagerly await publication of the complete nucleotide sequence of the Arcobacter genome. The abundant presence of four Arcobacter species in foods of animal origin and the recovery of these bacteria from surface and drinking water suggest an important role of these bacteria as foodborne or waterborne agent and possibly as zoonotic agent.