Infections after auxiliary partial liver transplantation. Experiences in the first ten patients

Summary In ten auxiliary partial liver transplant recipients selective bowel decontamination (SBD) was used to reduce infections due to gram-negative microorganisms and fungi. During SBD no gram-negative infections occurred. Candida peritonitis was observed in one patient. After discontinuation of SBD serious infections of gram-negative origin did occur and three fungal infections were seen. SBD seems to have a favourable effect in reducing infections by gram-negative microorganisms and fungi. Most striking was the number of enterococcal infections that occurred. Five out of ten patients developed enterococcal infections which in two cases contributed to a fatal outcome. These infections occurred after increase of the number of enterococci in faeces and concomitant positive cultures of bile, ascites or wound drains. This increase could be due to the use of SBD. Also, the kind of biliary anastomosis may play an important role in the relatively high incidence of enterococcal infections. In the postoperative period, recurrence of hepatitis B infection in the liver graft was observed in all patients with cirrhosis due to this virus. Problems caused by other viral infections or protozoal infections remained limited in these ten patients. Zusammenfassung Bei Patienten, bei denen eine auxiliäre, partielle Lebertransplantation durchgeführt wurde, wurde die selektive Darmdekontamination (SBD) eingesetzt, um Infektionen durch gramnegative Mikroorganismen und Pilze zu vermindern. Während SBD traten keine Infektionen durch gramnegative Bakterien auf. Bei einem Patienten wurde eine Candida-Peritonitis beobachtet. Nach Beendigung der SBD kam es zu schweren Infektionen durch gramnegative Bakterien, außerdem zu drei Pilzinfektionen. SBD hat offensichtlich einen günstigen Einfluß im Hinblick auf eine Verminderung von Infektionen durch gramnegative Erreger und Pilze. Bemerkenswert hoch war die Zahl der aufgetretenen Enterokokkeninfektionen. Bei fünf der zehn Patienten traten Enterokokkeninfektionen auf, die in zwei Fällen den letalen Ausgang mitbestimmten. Diesen Infektionen gingen ein Anstieg der Enterokokkenzahlen im Stuhl und zugleich positive Kulturen in Galle, Aszites und Wunddrainagen voraus. Es ist möglich, daß die SBD die Zunahme von Enterokokkeninfektionen begünstigte. Auch die Art der Gallengangsanastomose kann hierzu wesentlich beigetragen haben. Bei allen Patienten, bei denen die Zirrhose durch Hepatitis B Virus verursacht war, kam es postoperativ zu einem Rezidiv durch dieses Virus im Lebertransplantat. Probleme durch andere virale oder Protozoeninfektionen hielten sich bei diesen zehn Patienten in Grenzen

Transcription of the yop regulon from Y. enterocolitica requires trans acting pYV and chromosomal genes

Virulent Y. enterocolitica strains restrict their growth at 37 degrees C, in rich medium deprived of calcium. This property, called calcium dependency, correlates with pathogenicity. It is conditioned by a 70 kb plasmid called pYV. The analysis of calcium independent (Cl) insertion mutants defined a 20 kb region called the calcium region. This region contains at least three transcription units called virA, B and C. In growth restriction conditions, Y. enterocolitica releases and inserts in its outer-membrane several pYV encoded proteins (POMPs). By transposition mutagenesis using a mini-Mu dlac element, we localized plasmid genes encoding POMPs of 84, 51, 30 and 25 kDa. These genes appear to be scattered on pYV, outside the calcium region and to constitute a regulon. Transcription of these yop genes increased by factors of 3.5 (yop84) to 200 (yop51) when temperature was shifted from 25 to 37 degrees C. On the contrary, calcium had only a moderate effect. Transcription was also dependent on the culture medium and on a trans-acting factor encoded by the calcium region. One Cl double mutant severely affected in transcription of yop51 defined a new locus called virF in the calcium region of pYV. Transcription of the yop genes was very poor in E. coli K12, even in the presence of a fully functional calcium region