Characteristics of gallbladder microbiome in healthy dogs and cats, dogs with gallbladder mucocele, and cats with suspected cholangitis/cholangiohepatitis.

The aim of this study was to investigate and characterize the microbiome in bile samples obtained from dogs with gallbladder mucocele (6), cats with suspected cholangitis/cholangiohepatitis (4), as well as from healthy dogs (6) and cats (4). Our goal was to compare the microbiome patterns with clinical findings and bacterial culture results in diseases of the gallbladder and to identify a potential microbial biomarker of diseased groups. The microbial taxa composition revealed that Proteobacteria were the most dominant phylum in healthy and diseased individuals in all groups. Individuals from six families including Burkholderiaceae, Phyllobacteriaceae, Bradyrhizobiaceae, Sphingomonadaceae, Moraxellaceae, and Caulobacteraceae, constituted the core microbiome in the gallbladder of healthy dogs. A combination of LEfSe analysis and Taxa2ASV decomposer revealed that Pseudomonaceae and Ruminococcaceae exclusively occurred in the mucocele group. In conclusion, this study determined the core microbiome in the gallbladder of healthy dogs and the possible biomarkers (Pseudomonaceae and Ruminococcaceae) of gallbladder mucocele in dogs.

Le but de cette étude était d'étudier et de caractériser le microbiome dans des échantillons de bile obtenus auprès de chiens atteints de mucocèle de la vésicule biliaire (6), de chats suspectés de cholangite/cholangiohépatite (4), ainsi que de chiens (6) et de chats en bonne santé (4). Notre objectif était de comparer les modèles de microbiome avec les résultats cliniques et les résultats de cultures bactériennes dans les maladies de la vésicule biliaire et d'identifier un biomarqueur microbien potentiel des groupes malades. La composition des taxons microbiens a révélé que les protéobactéries constituaient le phylum le plus dominant chez les individus sains et malades de tous les groupes. Des individus de six familles, dont Burkholderiaceae, Phyllobacteriaceae, Bradyrhizobiaceae, Sphingomonadaceae, Moraxellaceae et Caulobacteraceae, constituaient le microbiome central de la vésicule biliaire de chiens en bonne santé. Une combinaison de l'analyse LEfSe et du décomposeur Taxa2ASV a révélé que les Pseudomonaceae et les Ruminococcaceae étaient exclusivement présentes dans le groupe des mucocèles. En conclusion, cette étude a déterminé le microbiome central de la vésicule biliaire de chiens en bonne santé et les biomarqueurs possibles (Pseudomonaceae et Ruminococcaceae) de la mucocèle de la vésicule biliaire chez le chien.(Traduit par Docteur Serge Messier).

Molecular epidemiology of antimicrobial-resistant Pseudomonas aeruginosa in a veterinary teaching hospital environment.

This study aimed to investigate sites for colonization and molecular epidemiology of antimicrobial-resistant Pseudomonas aeruginosa in a veterinary teaching hospital. Bacterial specimens from surface and liquid samples (n = 165) located in five rooms were collected three times every 2 months, and antimicrobial susceptibility was subsequently determined by minimum inhibitory concentrations. The genomes of resistant strains were further analyzed using whole-genome sequencing. Among 19 P. aeruginosa isolates (11.5%, 19/165), sinks were the most frequent colonization site (53.3%), followed by rubber tubes (44.4%), and anesthesia-breathing circuit (33.3%). The highest resistance to gentamicin (47.4%), followed by piperacillin/tazobactam (36.8%), levofloxacin (36.8%), and ciprofloxacin (36.8%), was observed from 19 P. aeruginosa isolates, of which 10 were resistant strains. Of these 10 antimicrobial-resistant isolates, five were multidrug-resistant isolates, including carbapenem. From the multilocus sequence typing (MLST) analysis, five sequence types (STs), including a high-risk clone of human ST235 (n = 3), and ST244 (n = 3), ST606 (n = 2), ST485 (n = 1), and ST3405 (n = 1) were identified in resistant strains. Multiresistant genes were identified consistent with STs, except ST235. The MLST approach and single nucleotide polymorphism analysis revealed a link between resistant strains from ward rooms and those from examination, wound care, and operating rooms. The improvement of routine cleaning, especially of sink environments, and the continued monitoring of antimicrobial resistance of P. aeruginosa in veterinary hospitals are necessary to prevent the spread of resistant clones and ensure infection control.

YIPF1, YIPF2, and YIPF6 are medial-/trans-Golgi and trans-Golgi network-localized Yip domain family proteins, which play a role in the Golgi reassembly and glycan synthesis.

In this study, we attempted to explore the function of three uncharacterized mammalian homologs of yeast Yip domain family proteins-YIPF6, a homolog of Yip1p, and YIPF1 and YIPF2, which are homologs of Yif1p. Immunofluorescence staining revealed that YIPF1, YIPF2, and YIPF6 mainly localize in the medial-/trans-Golgi and also partially in the trans-Golgi network (TGN). On treatment with brefeldin A (BFA), the homologs co-migrated partly with medial-/trans-Golgi markers and also with a TGN marker in earlier time point, but finally redistributed within cytoplasmic punctate structures that were distinct from medial-/trans-Golgi and the TGN markers. YIPF6 formed a stable complex separately with YIPF1 and YIPF2, and knockdown of YIPF6 reduced YIPF1 and YIPF2 levels. These results suggest that YIPF6 forms complexes with YIPF1 and YIPF2 for their stable expression and localization within the Golgi apparatus. Knockdown experiments showed that YIPF1 and YIPF2, by contrast, are not necessary for the expression and localization of YIPF6. The structure of the Golgi apparatus and its disassembly after BFA treatment were not significantly affected by the knockdown of YIPF1, YIPF2, or YIPF6. However, reassembly of the Golgi apparatus after the removal of BFA was markedly delayed by the knockdown of YIPF1 and YIPF2, but not by that of YIPF6. These results strongly suggest that free YIPF6 after disassociating with YIPF1 and YIPF2 interferes with the reassembly of the Golgi apparatus. Knockdown of YIPF1 and YIPF2, but not that of YIPF6, also reduced intracellular glycans in HT-29 cells. Thus, we confirmed that YIPF1, YIPF2, and YIPF6 play a significant role in supporting normal glycan synthesis.

Low cytoplasmic pH reduces ER-Golgi trafficking and induces disassembly of the Golgi apparatus.

The Golgi apparatus was dramatically disassembled when cells were incubated in a low pH medium. The cis-Golgi disassembled quickly, extended tubules and spread to the periphery of cells within 30 min. In contrast, medial- and trans-Golgi were fragmented in significantly larger structures of smaller numbers at a slower rate and remained largely in structures distinct from the cis-Golgi. Electron microscopy revealed the complete disassembly of the Golgi stack in low pH treated cells. The effect of low pH was reversible; the Golgi apparatus reassembled to form a normal ribbon-like structure within 1-2h after the addition of a control medium. The anterograde ER to Golgi transport and retrograde Golgi to ER transport were both reduced under low pH. Phospholipase A2 inhibitors (ONO, BEL) effectively suppressed the Golgi disassembly, suggesting that the phospholipase A2 was involved in the Golgi disassembly. Over-expression of Rab1, 2, 30, 33 and 41 also suppressed the Golgi disassembly under low pH, suggesting that they have protective role against Golgi disassembly. Low pH treatment reduced cytoplasmic pH, but not the luminal pH of the Golgi apparatus, strongly suggesting that reduction of the cytoplasmic pH triggered the Golgi disassembly. Because a lower cytoplasmic pH is induced in physiological or pathological conditions, disassembly of the Golgi apparatus and reduction of vesicular transport through the Golgi apparatus may play important roles in cell physiology and pathology. Furthermore, our findings indicated that low pH treatment can serve as an important tool to analyze the molecular mechanisms that support the structure and function of the Golgi apparatus.

Penicillium species-induced granuloma in a cat resulting in chronic lower urinary tract disease.

A 5-year-old, female neutered Persian cat was admitted to the Small Animal Hospital (Chulalongkorn University, Bangkok, Thailand) with clinical signs of dysuria, haematuria and partial urethral obstruction that had manifested over several months. The animal also had hyperkalaemia and severe azotaemia at the time of presentation. Urinalysis showed haematuria, pyuria and the presence of several transitional cells. In addition, ultrasonography demonstrated an extraluminal mass between the neck of urinary bladder and the colon. Fine-needle aspiration of the mass revealed a fungal form with branching and septate hyphae. Consequently, itraconazole treatment was prescribed and clinical signs of improvement were seen after 7 days. However, 1 month later, the cat died of acute anaemia. Necropsy revealed the presence of extraluminal multifocal fungal granuloma at the neck of the urinary bladder, and contracted kidneys. Histopathological analysis of the fungal granuloma was found to be composed of branching, septate hyphal fungi together with inflammatory cells. Subsequent fungal culture and identification revealed this to be a species of Penicillium.