Critical points and potential pitfalls of outbreak of IMP-1-producing carbapenem-resistant Pseudomonas aeruginosa among kidney transplant recipients: a case-control study.

BACKGROUND: Carbapenem-resistant Pseudomonas aeruginosa (CRPA) infection after kidney transplantation (KT) is associated with high mortality. AIM: To analyse an outbreak of infection/colonization with IMP-1-producing CRPA on a KT ward. METHODS: A case-control study was conducted. Cases were identified through routine surveillance culture and real-time polymerase chain reaction for carbapenemase performed directly from rectal swab samples. Controls were randomly selected from patients hospitalized on the same ward during the same period, at a ratio of 3:1. Strain clonality was analysed through pulsed-field gel electrophoresis (PFGE), and whole-genome sequencing was performed for additional strain characterization. FINDINGS: CRPA was identified in 37 patients, in 51.4% through surveillance cultures and in 49.6% through clinical cultures. The median persistence of culture positivity was 42.5 days. Thirteen patients (35.1%) presented a total of 15 infections, of which seven (46.7%) were in the urinary tract; among those, 30-day mortality rate was 46.2%. PFGE analysis showed that all of the strains shared the same pulsotype. Multilocus sequence typing analysis identified the sequence type as ST446. Risk factors for CRPA acquisition were hospital stay >10 days, retransplantation, urological surgical reintervention after KT, use of carbapenem or ciprofloxacin in the last three months and low median lymphocyte count in the last three months. CONCLUSION: KT recipients remain colonized by CRPA for long periods and could be a source of nosocomial outbreaks. In addition, a high proportion of such patients develop infection. During an outbreak, urine culture should be added to the screening protocol for KT recipients.

Parotid Salivary Gland Basal Cell Adenocarcinoma in a Big-eared Opossum (Didelphis aurita).

The opossum (family Didelphidae) is a marsupial endemic to the Americas. Apart from the South American short-tailed opossum (Monodelphis domestica) and the Virginia opossum (Didelphis virginiana), there is considerable lack of knowledge about the health and diseases of most opossum species. Among these, the big-eared opossum (Didelphis aurita) is found in Argentina, Brazil and Paraguay. Natural and experimental studies have shown this species to be susceptible to infectious agents with zoonotic potential and the animals may play a role in transmission of such agents. However, neoplasia appears to be uncommon in this species. We describe the gross, microscopical and immunohistochemical features of a parotid salivary gland basal cell adenocarcinoma in a free-living big-eared opossum. This case represents the first report of salivary gland neoplasia in opossums.

Hepatocellular carcinoma in a free-living marmoset (Callithrix sp.) with concomitant biliary trematodiasis.

Hepatocellular carcinoma (HCC) is rare in New World primates. We report the gross, microscopical, and immunocytochemical features of a spontaneous HCC in a free-living marmoset (Callithrix sp.). Hepatitis B and C virus and aflatoxin immunohistochemistry were negative; however, concomitant intra- and extrahepatic biliary trematodiasis could have played a role.