Cases of cryptosporidiosis co-infections in AIDS patients: a correlation between clinical presentation and GP60 subgenotype lineages from aged formalin-fixed stool samples

Nine cases of cryptosporidiosis co-infections in AIDS patients were clinically categorised into severe (patients 1, 3, 8 and 9), moderate (patients 4 and 5) and mild (patients 2, 6 and 7). Formalin-fixed faecal specimens from these patients were treated to obtain high quality DNA competent for amplification and sequencing of the 60-kDa glycoprotein (GP60) gene. Sequence analysis revealed that one patient was infected with Cryptosporidium hominis whereas the remaining eight patients were infected with C. parvum. Interestingly, the patients showing severe cryptosporidiosis harboured two subtypes within the C. parvum allelic family IIc (IIcA5G3 and IIcA5G3R2), whereas patients with moderate or mild infections showed various subtypes of the C. parvum allelic family IIa (IIaA14G2R1, IIaA15G2R1, IIaA17G3R1 and IIaA18G3R1)

Misregulation of mitochondria-lysosome contact dynamics in Charcot-Marie-Tooth Type 2B disease Rab7 mutant sensory peripheral neurons

Inter-organelle contact sites between mitochondria and lysosomes mediate the crosstalk and bidirectional regulation of their dynamics in health and disease. However, mitochondria-lysosome contact sites and their misregulation have not been investigated in peripheral sensory neurons. Charcot-Marie-Tooth type 2B disease is an autosomal dominant axonal neuropathy affecting peripheral sensory neurons caused by mutations in the GTPase Rab7. Using live super-resolution and confocal time-lapse microscopy, we showed that mitochondria-lysosome contact sites dynamically form in the soma and axons of peripheral sensory neurons. Interestingly, Charcot-Marie-Tooth type 2B mutant Rab7 led to prolonged mitochondria-lysosome contact site tethering preferentially in the axons of peripheral sensory neurons, due to impaired Rab7 GTP hydrolysis-mediated contact site untethering. We further generated a Charcot-Marie-Tooth type 2B mutant Rab7 knock-in mouse model which exhibited prolonged axonal mitochondria-lysosome contact site tethering and defective downstream axonal mitochondrial dynamics due to impaired Rab7 GTP hydrolysis as well as fragmented mitochondria in the axon of the sciatic nerve. Importantly, mutant Rab7 mice further demonstrated preferential sensory behavioral abnormalities and neuropathy, highlighting an important role for mutant Rab7 in driving degeneration of peripheral sensory neurons. Together, this study identifies an important role for mitochondria-lysosome contact sites in the pathogenesis of peripheral neuropathy

Genotyping of different Pseudomonas aeruginosa morphotypes arising from the lower respiratory tract of a patient taken to an Intensive Care Unit

Pseudomonas aeruginosa is an opportunistic pathogen and an ubiquitous environmental bacterium. Fifty-seven days after hospitalization, we isolated three distinct P. aeruginosa morphotypes (smooth, rough and mucoid) from the lower respiratory tract of a patient admitted to a Cardiology Intensive Care Unit (ICU). Moreover, a group of nine colony variants, arising from the three P. aeruginosa isolates growing in laboratory growth media, were also isolated. The resulting 12 isolates were characterised for antibiotic resistance profile and subjected to genotypic analysis by fluorescent-Amplified Fragment Length Polymorphism (f-AFLP) and automated repetitive extragenic palindromic-PCR (rep-PCR) fingerprinting. The three smooth, rough and mucoid morphotypes presented different antibiotic resistance profiles and genotyping analysis showed that they belonged to distinct clones, indicating that at day 57 after the admission the patient was simultaneously colonized by three distinct P. aeruginosa isolates. On the other hand, the nine colony variants presented heterogeneous antibiotic resistance profiles and clustered together with the three parental isolates. The understanding of the link between genotype plasticity and antibiotic resistance may contribute to improving our knowledge of this life-threatening pathogen. Copyright © by BIOLIFE, s.a.s

Characterization of peripheral blood CD34+ progenitor cells mobilized with chemotherapy and granulocyte colony-stimulating factor.

Peripheral blood (PB) mononuclear cells mobilized with chemotherapy and granulocyte colony-stimulating factor (G-CSF) were enriched in CD34+ cells; aliquots were seeded in long-term cultures (LTC) on bone marrow (BM)-derived stromal layers and in liquid cultures containing various growth factors. The final recovery of PB CD34+ cells was similar to normal BM controls, and no difference was found in the expression of CD33 and CD13 antigens; a lower number of CD34+/HLA-DR- cells was found in PB with respect to BM samples (p < 0.001). PB cells sustained hematopoiesis in LTC at least as long as BM cells. At week 3 and 4, PB total mononuclear cell (MC) and CD34(+)-selected cell cultures showed a higher nonadherent cell recovery compared to the respective BM controls (p = 0.05 and p < 0.01). The liquid culture of PB CD34+ cells in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and stem cell factor (SCF) resulted in a marked and long-lasting increase of colony-forming units-granulocyte/macrophage (CFU-GM). Taken together, our data suggest that chemotherapy and G-CSF-primed cells contain a considerable number of both committed and early precursors, accounting for the rapid hematopoietic recovery observed after their reinfusion following myeloablative chemotherapy