Generalized Transduction in Corynebacterium renale

A phage, designated RP28, was obtained which carried out generalized transduction in Corynebacterium renale, and 11 different auxotrophic markers were all transduced.     

Influence of acetohydroxamic acid on experimental Corynebacterium renale pyelonephritis.

The role of Corynebacterium renale urease in the establishment of pyelonephritis was studied by the oral administration of acetohydroxamic acid (AHA), a urease inhibitor, to experimentally infected rats. The bacteria were introduced by surgical insertion of a zinc disc containing 1 X 10(6) colony-forming units of C-renale into the urinary bladder whereas sterile discs were implanted in the bladders of the control animals. Daily administration of AHA via the drinking water did not halt the development of pyelonephritis. Larger doses, given by gavage, did accomplish this goal; that is, the pH of the urine was lowered, the number of colony-forming units of C. renale in the kidney was reduced drastically, and pyelonephritic lesions were observed in the kidney by light-microscopic examination. All experimental rats developed cystitis in varying degrees of severity. About 70% of the intact AHA given by gavage was excreted in the urine 24 h after administration of this compound. Rats implanted with a urease-negative mutant of C. renale displayed no signs of pyelonephritis but did develop cystitis.     

A numerical taxonomic study of the strains of three types of Corynebacterium renale.

Numerical analysis has been carried out on 100 features of 55 strains of Corynebacterium renale. Three phena were formed, which respectively corresponded to three immunological types of C. renale.     

Characterization of broad host range cryptic plasmid pCR1 from Corynebacterium renale

Plasmid pCR1 is a cryptic plasmid harboured by Corynebacterium renale. It is the smallest corynebacterial plasmid known to date. Although its natural host is animal corynebacteria, it can replicate in several strains of soil corynebacteria. It can also replicate in Escherichia coli, in which it is stably maintained. The copy number of pCR1 in this host is higher than that of pUC19, with which it shows unidirectional incompatibility. It is also incompatible with pBK2, a plasmid bearing the common corynebacterial replicon pBL1. Its size is 1488bp, as revealed by DNA sequencing. A total of eight open reading frames (ORF) were detected in this plasmid, the largest of which codes for a putative Rep protein of predicted molecular mass of 21kDa. The plasmid pCR1 can be mobilized by the plasmid R6K from E. coli to other corynebacteria. Sequence analysis revealed the presence of an oriT homologous to that of R64. An E. coli plasmid pKL1 shows more than 90% identity with pCR1. Like many coryenbacterial plasmids, pCR1 also replicates by rolling circle mode.     

Effect of hydroxamic acids on growth and urease activity in Corynebacterium renale.

Studies were conducted on the effect of four different hydroxamic acids (HA), hydroxyurea, acetohydroxamic acid, p-flurobenzoylhydroxamic acid and sorbylhydroxamic acid, on the growth and urease activity of Corynebacterium renale. The addition of each of these HA, at concentrations ranging form 10(-3) to 10(-5) M, to medium containing urea as the sole nitrogen source resulted in a lengthened lag period of growth the extent of which depended upon the concentration of each HA tested as well as the structure of the compound; that is, the size and (or) complexity of the side chain attached to the common terminal group of the molecule. However, the maximal growth levels achieved following conclusion of the exponential phase were not affected by the HA. Investigations on the effect of these HA on the urease activity of intact cells as well as cell-free extracts revealed that in each case the enzymatic activity was inhibited by each of the HA tested. The extent of inhibition with the intact cells was aobut one-half of that observed with cell-free extracts. Direct incubation of cell-free extracts as well as intact cells with each of the HA tested was required for maximal inhibition.     

Some Effects of Temperature on the Growth of F Pili

The effect of temperature on the production of F pili by an F(+) strain of Escherichia coli B/r was studied by electron microscopy and by a technique involving serum-blocking power. The latter method is based on the ability of F pili to adsorb F pili antibody which inhibits male-specific phage infection. The total amount of pili in a sample was estimated by serum-blocking power; the length of F pili and number per cell was determined by electron microscopy. Cell extracts prepared by sonic oscillation lacked serum-blocking power, suggesting that F pili are not present in the cytoplasm. The number of F pili per cell varied with the growth temperature, but the average length of F pili remained constant. Maximum number of pili per cell occurs between 37 and 42 C; below 37 C the number decreases, reaching zero at about 25 C. When cells are grown at 37 C, blended, and resuspended in fresh media at 25 C, they make F pili. These pili are probably assembled from a pool of subunits that were synthesized during growth at 37 C. The rates of assembly at 25 and 37 C, as judged by the rate of increase in length of F pili, are similar. When cells were grown at 25 C and shifted up to 37 C, there was a 30-min lag in pili production followed by a period of rapid outgrowth. When cells were shifted down from 37 to 20 C, outgrowth (assembly) of pili ceased, and approximately 50% of the attached pili were released in 2 min. No release was observed when cells were shifted to 0 C. This suggests that pili may be released from the cell by a mechanism that requires metabolic activity, but not the outgrowth of F pili.     

Distribution of Corynebacterium renale among healthy bulls with special reference to inhabitation of type III in the prepuce.

Distribution of Corynebacterium renale among apparently healthy bulls reared in Hokkaido was investigated. The organism was detected from 46 (39.3%) of 117 specimens of preputial cavity washing and from 60 (51.7%) of 116 specimens of semen. The isolates studied in this survey belonged to type III, except a few which belonged to type II. No type I strain was isolated from any bull. C. renale type III was isolated from the prepuce in six of seven bulls slaughtered and from urethra in three, but not at all from any other organ. In the seven bulls, no macroscopic changes were seen, but a slight infiltration of lymphocytes and formation of lymph nodules were noticed in the prepuce. No other microscopical changes could be demonstrated in any other organ. No serum antibody response was detected. To ascertain the virulence of C. renale isolated from the bulls, a strain of type II was inoculated into the urinary bladder of a healthy cow. The cow exhibited fever and hematuria on and after the 10th day. Typical cystitis was proved when the cow was necropsied on the 14th day after inoculation. From these result it is conceived that C. renale type II organisms inhabit the prepuce of apparently healthy bulls at a high rate, without inducing any disturbance.     

The Nanomechanical Properties of Lactococcus lactis Pili Are Conditioned by the Polymerized Backbone Pilin

Pili produced by Lactococcus lactis subsp. lactis are putative linear structures consisting of repetitive subunits of the major pilin PilB that forms the backbone, pilin PilA situated at the distal end of the pilus, and an anchoring pilin PilC that tethers the pilus to the peptidoglycan. We determined the nanomechanical properties of pili using optical-tweezers force spectroscopy. Single pili were exposed to optical forces that yielded force-versus-extension spectra fitted using the Worm-Like Chain model. Native pili subjected to a force of 0–200 pN exhibit an inextensible, but highly flexible ultrastructure, reflected by their short persistence length. We tested a panel of derived strains to understand the functional role of the different pilins. First, we found that both the major pilin PilB and sortase C organize the backbone into a full-length organelle and dictate the nanomechanical properties of the pili. Second, we found that both PilA tip pilin and PilC anchoring pilin were not essential for the nanomechanical properties of pili. However, PilC maintains the pilus on the bacterial surface and may play a crucial role in the adhesion- and biofilm-forming properties of L. lactis.     

Physiological and biochemical consequences of host-plasmid interaction--a case study with Corynebacterium renale, a multiple cryptic plasmid containing strain

Corynebacterium renale harbors four small cryptic plasmids, pCR1, pCR2, pCR3 and pCR4, and can be a good system for understanding host-plasmid interactions. In the present study, effect of plasmid loss and their subsequent introduction on various properties of the host was evaluated. Loss of plasmids caused a reduction in bacterial size and also slowed down their growth rate, μ, and respiratory rate, r. Both μ and r values were partially recovered in C. renale R, obtained by retransformation of the cured strain with all the four cryptic plasmids. Further delineation revealed that a 3153bp plasmid pCR2 alone is sufficient for the observed increase in μ in C. renale R. The advantages conferred by the remaining three plasmids may be are two subtle to be seen under laboratory conditions. Overall, the observations point to the gross metabolic crisis in the host partly as a result of loss of plasmids. Based on the findings, a mutualistic relationship between the host and the plasmids resulting from their coevolution is proposed.     

Some observations on Corynebacterium pyogenes infection of the bovine uterus

Throughout the non-gravid period, bacteriological samples and endometrial biopsy specimens were taken repetitively from the uteri of 93 cows in 9 dairy herds. The genital organs of 7 of the 14 cows which developed chronic purulent endometritis or pyometra were examined at slaughter 8 to 9 months after parturition. $\text{C.}$$\text{pyogenes}$ was recovered at least once from 61 (65.6 $\text{per}$$\text{cent.}$) of the cows. The highest rate of infection was found during the second week post-partum. Intrauterine infection with $\text{C.}$$\text{pyogenes}$ invariably induced endometritis. The severity of the endometrial reaction was determined by the duration of the infection but the lesions never progressed to the “gland site mass” lesions and extensive stromal sclerosis which have been described as the “significant lesions” in endometritis.The duration of the infection also determined the effect of $\text{C.}$$\text{pyogenes}$ on fertility. Transient infection during the puerperium did not affect fertility; transient infection at a later period reduced fertility to one service, rarely to a second or third service; persistent infection induced chronic purulent endometritis or pyometra accompanied initially by functional anoestrum and, after some months, by organic anoestrum. The factors which determined the duration of the intrauterine infection with $\text{C.}$$\text{pyogenes}$ were not identified.