Isolation of Lambda Transducing Phage with the bio Genes Inserted between Lambda Genes P and Q

Plaque-forming, biotin-transducing phages were constructed with the bio genes inserted between lambda genes P and Q. These phages were isolated for the eventual aim of fusing the lambda Q gene to the bio operon. The following steps were used to construct these phages: A defective temperature-sensitive lysogen was constructed with the bio genes adjacent to and to the left of lambda genes beta NcI857OPQSRA. Heat-resistant survivors were screened for deletions with endpoints in the bio operon and to the right of lambda P and to the left of lambda A. Five of approximately 1,600 heat-resistant survivors had these properties. Two had the gene order bioAB .... lambda QSRA. When these two strains were lysogenized with lambda cI857b221 and heat induced, the desired transducing phages were obtained. We characterized these phages and studied one in detail. Two-thirds of the plaque-forming transducing phages isolated carried the entire bioB gene and only part of the bioA gene, and one-third carried the entire bioA and bioB genes. The phages isolated lost the bio genes upon propagation, indicating that they contain a partial duplication of phage genes. The duplication was shown not to involve the entire lambda Q gene in one of these phages, lambda bioq1b221. A recombinant of this phage, lambda Nam7am53c17b221, failed to form plaques under biotin-derepression conditions. We conclude that if the lambda Q gene was fused to the bio operon in this phage, not enough lambda Q gene product was made to allow phage propagation.     

Isolation and classification of acetic acid bacteria from high percentage vinegar fermentations

Summary A method for growing acetic acid bacteria from high percentage submerged vinegar fermentations was established by overflowing soft agar, containing acetic acid, with fermenting reactor fluid. Mixed cultures were found in a submerged process that was working well (1), in a submerged process that had broken down (2), and in a vinegar generator (3). The strains differed in part from each other with respect to tolerance towards acetic acid, ethanol, pH and in other physiological criteria. All strains that were isolated from (1) and some from (3) were specialized for acetate media as they needed acetic acid and low pH values (2.1–3.8) in addition to yeast extract and glucose or ethanol. We suppose that they belonged to the acetic acid-producing strains active in the process. None of the strains derived from (2) was of this acetophilic type. All except one of the stains from (2) belonged to the species Acetobacter hansenii, the other cultures were of A. pasteurianus.     

Spleen-specific expression of the malaria-inducible intronless mouse gene imap38.

We characterize the mouse gene imap38 and its inducibility by Plasmodium chabaudi malaria among different lymphoid tissues and mouse strains of different H-2 complex and non-H-2 background. Imap38 is a single copy gene assigned to chromosome 6B. It consists of only one exon of 1900 base pairs encoding a highly basic 25.8-kDa protein. Confocal laser scanning microscopy localizes differently tagged IMAP38 proteins in nuclei of transfected cells. Reporter gene assays reveal that the 1730-base pair 5'-flanking region, containing an RSINE1 repeat immediately adjacent to initiation site +1, exhibits promoter activity in nonmurine cells, while it is largely repressed in diverse mouse cell lines, which corresponds to the situation in mouse tissues. P. chabaudi malaria induces imap38 expression almost exclusively in the spleen but not in other lymphoid organs. Parasite lysates are able to induce imap38 in the spleen, but not in spleen cells ex vivo. Activation of spleen cells by LPS and other stimuli is not sufficient to induce imap38. Inducibility of imap38 requires signals from both parasites and the intact spleen, and it is controlled by genes of that non-H-2 background, which also controls development of protective immunity against P. chabaudi malaria.     

The occurrence of bacteriophages in spirit vinegar fermentation

Summary Bacteriophages in concentrations of approximately 10⁸–10⁹ particles/ml were demonstrated in culture lysates of industrial submerged spirit vinegar fermentations running in different European vinegar factories. Besides frequently found fragments of phages, two types of phages could be described. The frequent type I seems to belong to Bradley-group A; type II, with a remarkably larger head, may belong to group C. For simulation in the laboratory a phage-contaminated industrial culture was kept over 102 charges (time of cycle 24->240 h) in a semicontinuously operated 8-1 fermentor. A close relationship between spontaneous breakdowns and phage occurrence exists. Discrimination of breakdowns caused by lack of ethanol could not be made. Attempts to establish a bioassay for the phages failed presumably because of the instability of the phages. Continuing cultivation and waiting for secondary growth finally results in stable and productive fermentation.     

Toll-Like Receptor Polymorphisms and Susceptibility to Urinary Tract Infections in Adult Women

Background

Although behavioral risk factors are strongly associated with urinary tract infection (UTI) risk, the role of genetics in acquiring this disease is poorly understood.

Methodology/Principal Findings

To test the hypothesis that polymorphisms in Toll-like receptor (TLR) pathway genes are associated with susceptibility to UTIs, we conducted a population-based case-control study of women ages 18–49 years. We examined DNA variants in 9 TLR pathway genes in 431 recurrent cystitis (rUTI) cases, 400 pyelonephritis cases, and 430 controls with no history of UTIs. In the Caucasian subgroup of 987 women, polymorphism TLR4_A896G was associated with protection from rUTI, but not pyelonephritis, with an odds ratio (OR) of 0.54 and a 95% confidence interval (CI) of 0.31 to 0.96. Polymorphism TLR5_C1174T, which encodes a variant that abrogates flagellin-induced signaling, was associated with an increased risk of rUTI (OR(95%CI): 1.81 (1.00–3.08)), but not pyelonephritis. Polymorphism TLR1_G1805T was associated with protection from pyelonephritis (OR(95%CI): 0.53 (0.29–0.96)).

Conclusions

These results provide the first evidence of associations of TLR5 and TLR1 variants with altered risks of acquiring rUTI and pyelonephritis, respectively. Although these data suggest that TLR polymorphisms are associated with adult susceptibility to UTIs, the statistical significance was modest and will require further study including validation with independent cohorts.     

Occasional intraguild predation structuring small mammal assemblages: the marsupial Didelphis aurita in the Atlantic Forest of Brazil

The didelphid marsupial, Didelphis aurita, is suggested as an intraguild predator and as key‐species in small mammal assemblages of the Atlantic Forest of Brazil. The field experiments required to test this hypothesis are complex to implement, but the recent revival of regression methods offers a viable alternative. Here we use the dynamic and static regression methods to determine the importance of D. aurita as a competitor and intraguild predator. Capture–recapture data from two localities in the Rio de Janeiro State were used, Garrafão (municipality of Guapimirim), a coastal forest of the Serra do Mar, and Barra de Maricá, a costal sand dune vegetation. Population and microhabitat variables were monitored from April 1997 to April 2003 in Garrafão, and from January 1986 to July 1990 in Barra de Maricá. Microhabitat variables were related to Canopy, Plant, Litter and Rock covers, Obstruction from 0 to 1.5 m, and Number of logs. Exploitation competition was tested by the dynamic method, which models the effects of D. aurita on the per capita growth rate of a species. Interference by predation or competition was tested by the static method, where the abundance of D. aurita at trap stations was regressed against the abundance of other small mammals, after removal of any variation associated with microhabitat factors. Exploitation competition was not detected, but the interference of D. aurita was pervasive, affecting all small mammals studied in the two localities. The clear avoidance of D. aurita by all small mammals tested in two localities of different physiognomies indicates that it functions as an intraguild predator, even if actual predation by D. aurita is an occasional event.     

Caging targets for destruction

Intracellular bacterial pathogens engage in a tug-of-war with innate host defenses. In this issue of Cell Host & Microbe, Mostowy et?al. (2010) identify a role for the septin family of cytoskeletal proteins in targeting intracellular Shigella to the autophagy pathway.