Acute kidney injury associated with Yersinia pseudotuberculosis infection: Forgotten but not gone

Chronic Leptin Deficiency Improves Tolerance of Physiological Damage and Host-Pathogen Cooperation during Yersinia pseudotuberculosis Infection

To combat infections, hosts employ a combination of antagonistic and cooperative defense strategies. The former refers to pathogen killing mediated by resistance mechanisms, while the latter refers to physiological defense mechanisms that promote host health during infection independent of pathogen killing, leading to an apparent cooperation between the host and the pathogen. Previous work has shown that Leptin, a pleiotropic hormone that plays a central role in regulating appetite and energy metabolism, is indispensable for resistance mechanisms, while a role for Leptin signaling in cooperative host-pathogen interactions remains unknown. Using a mouse model of Yersinia pseudotuberculosis (Yptb) infection, an emerging pathogen that causes fever, diarrhea, and mesenteric lymphadenitis in humans, we found that the physiological effects of chronic Leptin-signaling deficiency conferred protection from Yptb infection due to increased host-pathogen cooperation rather than greater resistance defenses. The protection against Yptb infection was independent of differences in food consumption, lipolysis, or fat mass. Instead, we found that the chronic absence of Leptin signaling protects from a shift to lipid utilization during infection that contributes to Yptb lethality. Furthermore, we found that the survival advantage conferred by Leptin deficiency was associated with increased liver and kidney damage. Our work reveals an additional level of complexity for the role of Leptin in infection defense and demonstrates that in some contexts, in addition to tolerating the pathogen, tolerating organ damage is more beneficial for survival than preventing the damage.

Extraintestinal Manifestation of Yersinia pseudotuberculosis Bacteremia as Acute Hepatitis: Case Report and Review of the Literature

Yersinia pseudotuberculosis is a causative agent of foodborne zoonosis that usually causes self-limiting pseudoappendicitis. Y. pseudotuberculosis infection also causes systemic spread or extraintestinal manifestations in patients with predisposing conditions. Here, we present a case of acute hepatitis with Y. pseudotuberculosis bacteremia in a 30-year-old man. He was previously healthy without significant medical history other than obesity and current smoking. At the time of admission, he presented with high fever accompanied by chills, jaundice, abdominal pain, and watery diarrhea. Laboratory studies revealed leukocytosis and elevated liver function parameters. A stool culture showed no causative pathogens. Empiric antibiotic therapy with ceftriaxone and metronidazole was administered. Y. pseudotuberculosis was later isolated from the initial blood culture performed on the day of admission using MALDI-TOF mass spectrometry. Antibiotic treatment was continued based on the susceptibility testing results from MALDI-TOF MS and VITEk^®2, as well as clinical and laboratory improvements. The patient was discharged on the tenth day of admission and remained healthy with no recurrence during the 12-month follow-up. Here, we review the literature on the systemic infection caused by Y. pseudotuberculosis, including extraintestinal manifestations. This case highlights that Y. pseudotuberculosis may be considered a differential causative organism in patients with acute colitis and hepatitis.

T4-like Bacteriophages Isolated from Pig Stools Infect Yersinia pseudotuberculosis and Yersinia pestis Using LPS and OmpF as Receptors

The Yersinia bacteriophages fPS-2, fPS-65, and fPS-90, isolated from pig stools, have long contractile tails and elongated heads, and they belong to genus Tequatroviruses in the order Caudovirales. The phages exhibited relatively wide host ranges among Yersinia pseudotuberculosis and related species. One-step growth curve experiments revealed that the phages have latent periods of 50-80 min with burst sizes of 44-65 virions per infected cell. The phage genomes consist of circularly permuted dsDNA of 169,060, 167,058, and 167,132 bp in size, respectively, with a G + C content 35.3%. The number of predicted genes range from 267 to 271. The phage genomes are 84-92% identical to each other and ca 85% identical to phage T4. The phage receptors were identified by whole genome sequencing of spontaneous phage-resistant mutants. The phage-resistant strains had mutations in the ompF, galU, hldD, or hldE genes. OmpF is a porin, and the other genes encode lipopolysaccharide (LPS) biosynthetic enzymes. The ompF, galU, and hldE mutants were successfully complemented in trans with respective wild-type genes. The host recognition was assigned to long tail fiber tip protein Gp38, analogous to that of T-even phages such as Salmonella phage S16, specifically to the distal β-helices connecting loops.