Nocardiosis in a kidney-pancreas transplant.

34-year-old man with chronic renal and pancreas failure in complicated diabetic disease received a kidney-pancreas transplantation. On the 32nd postoperative day, an acute kidney rejection occurred and resolved with OKT3 therapy. The patient also presented refractory urinary infection by E. Fecalis and M. Morganii, and a focal bronchopneumonia in the right-basal lobe resolved with elective chemotherapy. During the 50th post-operative day, an intense soft tissue inflammation localized in the first left metatarsal-phalangeal articulation occurred (Figure 1) followed by an abscess with a cutaneous fistula and extension to the almost totality of foot area. The radiological exam revealed a small osteo-lacunar image localized in the proximal phalanx head of the first finger foot. From the cultural examination of the purulent material, N. Asteroides was identified. An amoxicillin-based treatment was started and continued for three months, with the complete resolution of infection This case is reported for its rarity in our casuistry, and for its difficult differential diagnosis with other potentially serious infections.

A case of Cunninghamella bertholettiae rhino-cerebral infection in a leukaemic patient and review of recent published studies.

Cunninghamella bertholletiae infection occurs most frequently in neutropenic patients affected by haematological malignancies, is associated with an unfavourable outcome. We report a case of rhino-mastoidal fungal infection in a leukaemic patient. Bioptical tissue cultures yield the isolation of a mould with typical properties of Cunninghamella species. Liposomal amphotericin B (L-Amb) therapy combined with surgical intervention brought the lesion to recovery. Nevertheless, the patient died 14 days after bone marrow transplantation (BMT) from bacterial sepsis. Mastoiditis was documented at CT-scan. The conditioning regimen probably caused the reactivation of the Cunninghamella infection that led to the patient's fatal outcome; fungal hyphae were detected after autopsy of brain and lung tissue.

Soft-tissue infection with Absidia corymbifera and kidney complications in an AIDS patient.

We describe a case of primary cutaneous Absidia corymbifera infection in an AIDS patient with renal complications. The Sensititre YeastOne panel was adopted to determine antifungal susceptibility and liposomial amphotericin B was used which initially produced a significant clinical response.

Distinct regulation of HLA class II and class I cell surface expression in the THP-1 macrophage cell line after bacterial phagocytosis.

Expression of HLA and CD1b molecules was investigated in the THP-1 macrophage cell line within 2 weeks following phagocytosis of mycobacteria or Escherichia coli. During the first 2-3 days, cell surface expression of HLA class II and CD1b was drastically down-modulated, whereas HLA class I expression was up-modulated. In the following days both HLA class II and CD1b expression first returned to normal, then increased and finally returned to normal with kinetics similar to that observed for the steadily increased HLA class I. The initial down-modulation of HLA class II and CD1b cell surface antigens was absolutely dependent on phagocytosis of bacteria. Further studies indicated that initial HLA class II cell surface down-modulation (1) was not due to reduced transcription or biosynthesis of mature HLA class II heterodimers, (2) was only partially, if at all, rescued by treatment with IFN-gamma, although both mRNA and corresponding intracellular proteins increased up to sixfold with respect to untreated cells, and (3) resulted in failure of THP-1 cells to process and present mycobacterial antigens to HLA-DR-restricted antigen-specific T cell lines. The existence of a transient block of transport of mature HLA class II heterodimers to the cell surface in the first days after phagocytosis of bacteria may have negative and positive consequences: it decreases APC function early but it may increase it later by favoring optimal loading of bacterial antigens in cellular compartments at high concentration of antigen-presenting molecules.

Micrococci demonstrate a phosphatase activity which is repressed by phosphates and which can be differentiated from that of staphylococci.

The phosphatase activities of 114 micrococcal strains belonging to seven different species and of an additional 150 unspeciated micrococcal strains were evaluated on solid media at various pHs containing or not containing phosphates. In the presence of phosphates, only nine strains (five unspeciated strains, one Micrococcus luteus strain, and three Micrococcus varians strains) yielded a positive reaction on plates at pH 8. In media (at pH 8) deprived of phosphates, in contrast, all but 15 strains demonstrated clear-cut phosphatase activity. Acid phosphatase could not be evaluated on solid media since none of the strains grew satisfactorily on plates at pH 5. The phosphatase activities of seven (one or two for each species, which included phosphatase-negative strains) of the strains whose colonies proved phosphatase negative at pH 8 and of 18 (two or three strains per species) of those with phosphatase-positive colonies were evaluated at pH 5 and 8.5 in toluene-treated cells which had been grown in liquid media at pH 7 containing or not containing phosphates. All strains demonstrated distinct phosphatase activity at both pHs when grown in media not containing phosphates. In contrast, when strains were grown in the presence of such substances, virtually no activity was observed at pH 8.5, and, generally, a much reduced activity was observed at pH 5. The phosphatase activity of micrococci of the various species (three to eight strains per species) was also compared with that of staphylococci of different species (5 to 10 strains per species) by the methyl green-phenolphthalein diphosphate method, the sensitivity of which can be varied by using different enzyme substrates.(ABSTRACT TRUNCATED AT 250 WORDS)

Phosphatase activity of staphylococci is constitutive in some species and repressed by phosphates in others.

The phosphatase activities of colonies of staphylococcal strains belonging to the 10 species most frequently isolated from specimens of human origin were evaluated on media with undetermined inorganic phosphate contents and on media supplemented with known amounts of phosphates. All strains of all species tested were phosphatase positive on plates that were not supplemented with inorganic phosphates when the pH of the medium was high. In media supplemented with 0.3% phosphates at low and high pH, all strains of Staphylococcus aureus, almost all strains of S. epidermidis and S. xylosus, and none of the other species tested were phosphatase positive. Thirty S. simulans strains were grown in broths at pH 7 with and without phosphates, and the phosphatase activities of the cells were assayed at pH 5.5 and 8 in the absence of phosphates. At pH 8, all strains gave a strong positive reaction when grown in the absence of phosphates and a negative reaction when grown in the presence of these salts at 0.3%. It was concluded that all the species of staphylococci tested possess phosphatase activity and that the staphylococcal phosphatases are constitutive in some species and repressed in others.

[Action of clindamycin on bacteria adhering to plastic materials]. / Attività della clindamicina su batteri adesi alle materie plastiche.

The coagulase negative staphylococci capable of adhering to solid surfaces have been recognised as aetiological agents of infections associated with the presence of plastic biomedical prostheses. The study of antibiotic activity by traditional in vitro methods has proved unpredictive when applied to this type of infection: we have therefore used a calorimetric technique. Like other antibiotics, clindamycin was not effective in eradicating colonisation of biomedical prostheses. Studies on the activity of the antibiotic used in the prophylaxis of these infections in likely to be more promising.

Treatment of urinary tract infections with ciprofloxacin.

Urinary tract infections in 32 patients were treated with 250 mg of ciprofloxacin twice daily for seven to eight days. Clinical and laboratory examinations were performed before and after treatment. The infections were eradicated in 30 of the 32 patients. Ciprofloxacin was well tolerated by all patients.

In vitro antibacterial activity of ceftizoxime against gram-negative strains.

The in vitro activity of ceftizoxime against 200 clinical isolates of Enterobacteria and Pseudomonas, was compared with those of other beta-lactam antibiotics such as: cefotaxime, cefoperazone, cefuroxime, and the aminoglycosides gentamicin and amikacin. Ceftizoxime inhibited Escherichia coli and Klebsiella pneumoniae with doses from two to four fold lower than cefotaxime. Ceftizoxime and cefotaxime were more active than cefuroxime and cefoperazone against Enterobacter spp., and Proteus morganii. Ninety percent of the Serratia spp. were inhibited at 0.2 microgram/ml of ceftizoxime whereas the other cephalosporins needed doses up to thirty-two fold higher. The rest of the Proteus spp. were inhibited 90% with 0.8 or 3.2 micrograms/ml of ceftizoxime; on the contrary, to inhibit the same percentage of these bacteria, doses two to sixteen fold higher than cefotaxime or other cephalosporins were needed. Ceftizoxime was less active than amikacin against multiresistant Pseudomonas spp. Strains isolated from urine were generally more resistant to antibiotics than those encountered in other clinical material.

High-level potentiation of lysostaphin anti-staphylococcal activity by lysozyme.

The purpose of this study was to determine whether lysostaphin would enhance its anti-staphylococcal efficacy in combination with lysozyme. Minimum inhibitory concentrations (MICs) of lysostaphin and lysozyme were separately determined for 41 strains belonging to 10 different species of human staphylococci. Lysozyme was virtually inactive and showed MICs of 15 mg/ml. On the contrary, all strains were susceptible to lysostaphin and showed MICs ranging from 2.5 to 60 micrograms/ml for the different Staphylococcus species. When the MIC of lysostaphin was determined in media containing submultiples of the MIC of lysozyme, the values obtained were much lower. The reduction of the lysostaphin MIC ranged from 16- to 200-fold in the different species tested. In Staphylococcus aureus, in particular, the combination of lysostaphin with 1.5 mg of lysozyme per ml reduced the MIC of lysostaphin by 25-fold. The activities of two combinations of the two enzymes were evaluated: one combination was expected to be active on S. aureus only, and the other combination was expected to inhibit all Staphylococcus strains. The first combination (0.5 micrograms of lysostaphin plus 0.5 mg of lysozyme per ml) was inhibitory to all of the 84 S. aureus strains tested, whereas 137 of 151 strains of other Staphylococcus species were unaffected. On the contrary, all of the 235 Staphylococcus strains tested were inhibited by the second combination (4 micrograms of lysostaphin plus 5 mg of lysozyme per ml). The possible mechanisms of lysostaphin potentiation by lysozyme are considered, and the potential use of a lysostaphin-lysozyme combination for topical therapy of staphylococcal infections resistant to other antibiotics is discussed.