Colonies Of Strain Research Articles

Effect of Laboratory Rearing on the Reproductive Biology of the Lone Star Tick (Acarina: Ixodidae)

Studies on the reproductive biology of lone star ticks, Amblyomma americanum (L.), freshly collected from the field, ticks taken from a 25-year established colony, and ticks from reciprocal crosses between wild and colony ticks showed that colony ticks statistically differed significantly in several parameters. Engorged colony females weighed less, took longer to engorge, had longer preoviposition and oviposition periods, laid fewer eggs per female, converted less of the engorged weight to eggs, and had significantly lower egg hatch than wild females. Reciprocal crosses between wild and colony ticks indicated that most reproduction characteristics of wild females mated to colony males were similar to those of wild females mated to wild males; and colony females mated to wild males had reproduction characteristics similar to those of colony females mated to colony males. Reproduction data collected in 1970 of the colony strain were similar to current data from the same strain. Thus, lengthy periods of colonization affected most parameters of reproductive biology of A. americanum

台湾および日本産コガタアカイエカにみられた生態的性質の差異

台湾および日本産コガタアカイエカにみられた生態的性質の差異

The ability of Mycoplasma mycoides subspecies mycoides and closely related strains from goats and sheep to immunize mice against subspecies capri.

Small colony (SC) strains of Mycoplasma mycoides subsp. mycoides from contagious bovine pleuropneumonia (CBPP) and from goats were compared with large colony (LC) strains of so-called M. mycoides subsp. mycoides from goats and sheep by means of a cross-protection test in which mice were challenged with M. mycoides subsp. capri. Of 13 LC strains, all gave partial cross-protection, and 11 were shown to be more closely related than four SC strains to subspecies capri. In a further experiment, six SC strains--three from CBPP and three from goats--all gave weak partial cross-protection against subspecies capri.

Transmission of St. Louis encephalitis virus from Argentina by mosquitoes of the Culex pipiens (Diptera: Culicidae) complex.

St. Louis encephalitis (SLE) virus transmission cycles in tropical America and temperate South America are poorly defined. Elucidation of these cycles may help to explain basic differences between these areas and temperate North America with regard to disease incidence and severity of clinical illness due to SLE virus. Results of the first experimental studies on the virus-vector relationships of a SLE viral strain and a mosquito strain from Argentina are presented. A mosquito strain and a SLE viral strain from temperate North America were also included in the study in order to have a basis for comparison. Colony strains of Culex pipiens quinquefasciatus from Esperanza, Santa Fe Province, Argentina, and Cx. pipiens complex mosquitoes from Memphis, Tennessee, USA, were fed on chicks infected with either of 2 SLE viral strains from Esperanza and Dayton, Ohio, USA. On the 20th day of extrinsic incubation, 100% of the Argentina mosquitoes were infected irrespective of the viral strain used. A high proportion of Memphis mosquitoes became infected (87.8% and 89.8%), but they were less efficient in transmitting virus than their Argentina counterparts (58.3% vs. 90.0% Ohio SLE virus, and 40.0% vs 90.5% Argentina SLE virus). These differences may be due, at least in part, to the fact that the Memphis mosquitoes had fed on viremic chicks circulating less virus. Our results indicate that the strain of Cx. p. quinquefasciatus from Argentina is a very efficient vector of SLE virus under experimental conditions, and that the SLE viral strain from Argentina does not differ markedly from a temperate North American strain in its ability to infect and be transmitted by members of the Cx. pipiens complex.

Variation in susceptibility among colony strains of Culex tritaeniorhynchus to Japanese encephalitis virus infection.

The susceptibilities to Japanese encephalitis virus of eight strains of Culex tritaeniorhynchus, seven domestic and one from Taiwan, were studied quantitatively by the membrane feeding technique. Six of them, originated from the main islands of Japan (Honshu and Kyushu) and Okinawa, had moderate susceptibilities to the virus. One strain from Amami Island was slightly more susceptible than moderate strains and was sixfold more susceptible than Taiwan strain. The differences, were statistically significant, but too small to perform genetic analysis for the susceptibility of the mosquito to the virus.

Immunoprecipitation of Triton X-100-solubilized Mycoplasma mycoides proteins.

Mycoplasma mycoides subsp. mycoides (PG1 and strain Y) proteins were solubilized in Triton X-100, and the antigenic proteins were precipitated from this complex mixture by addition of antiserum and then separated by two-dimensional gel electrophoresis. Of the 300 proteins solubilized, about 10 were precipitated. Proteins of PG1, a slow-growing, small colony (SC) strain, were precipitated by antiserum to PG1 and by antiserum to strain Y, a fast-growing, large colony (LC) strain. Similarly, strain Y proteins were precipitated by antiserum to PG1 and by antiserum to strain Y. The few proteins precipitated in this way gave similar patterns after two-dimensional gel electrophoresis indicating that many of the dominant protein antigens of PG1 and strain Y are shared. Antiserum to Mycoplasma mycoides subsp. capri (PG3) also precipitated some proteins of strain Y. Antiserum to Mycoplasma gallisepticum gave no reaction with any M. mycoides antigens. It was concluded that, in addition to the polysaccharide antigens, there are proteins in M. mycoides that are antigenic and that some of these are found in both the SC and LC strains of subsp. mycoides and also in subsp. capri.

大阪北港産イエバエと高槻系イエバエの発育に及ぼす温度の影響

大阪北港産イエバエと高槻系イエバエの発育に及ぼす温度の影響

Role of urinary solutes in natural immunity to gonorrhea.

Natural resistance of the male urethra to gonococci has not been explained by classical immune mechanisms but could result from antibacterial properties of urine. Accordingly, we measured survival in midmorning urine of 10(7) F-62 T2 gonococci per ml by serial dilutions and plate counts. Fifteen killer urines from eight people all killed greater than 3 logs (average, 5.3), and 13 of 15 were sterilized. Fourteen nonkiller (inhibitor) urines from seven subjects allowed no growth. Killer urines were more acidic (pH 5.4 versus 6.4) and more concentrated (861 versus 717 mosmol/kg) than nonkillers. Upon addition of hydrogen ion, urea, and sodium chloride to urines and broth, pH proved to be the major killing factor, but urea and NaCl were also bactericidal. Susceptibility to urine bactericidal power did not vary with colony type (T2 versus T4) or strain (F-62 versus two fresh isolates). Killing was rapid (0.5 to 3 h) and not bacteriolytic. Escherichia coli multiplied 10-fold in urines that inhibited growth of gonococci. Thus, the bacteriostatic effect of urine may explain why gonococci do not infect the bladder and kidney during gonorrhea. The bactericidal properties of urine may contribute to resistance against gonococcal urethritis.

Experimentelle xenogene Immunpankreatitis Immunhistologische, enzymhistochemische und ultrastrukturelle Untersuchungen

Repeated intraperitoneal injections of anti-mouse pancreas rabbit serum or of anti-mouse pancreas guinea pig serum produce a chronical sclerotizing pancreatitis. This study has the aim to contribute to the further elucidation of the changes which occur in the acinar cells, as well as to the etiology and pathogenesis of immune pancreatitis, by means of immunohistological, enzyme histochemical and electron microscopic studies. Anti-mouse pancreas rabbit serum was obtained by sensitization of rabbits with an admixture of AB-mouse pancreas extract (100,000 g - supernatant) and complete Freund's adjuvant [details see NIZZE, Exp. Path. (1975a)]. The presence of precipitating mouse pancreas antibodies in the rabbit serum was ascertained by the agargel diffusion test according to Duchterlony (1958). The experiments were performed with 54 adult male white mice (AB colony strain) of 22 to 30 g.b.s. (averagely 26 g). The animals were divided into 4 groups which were treated as follows: 1. 24 mice with anti-mouse pancreas rabbit serum, 2. 12 mice with rabbit normal serum, 3. 12 mice with physiological saline, 4. 6 mice remained untreated (controls) Always 4 animals of the group 1 as well as each 2 of the groups 2 and 3 were administered in total 1, 3, 5, 9, 17 or 33 intraperitoneal injections of 0.3 ml of the correspondent serum or with physiological saline within 3 hours, 1, 2, 4, 8 or 16 days. The last injection was regularly applied 3 hours before sacrification by decapitation. The time of sacrification was always at 11.00 o'clock a.m. For immunohistological and enzyme histochemical investigations 10 mum thick cryostat sections were prepared consisting of pancreatic specimens piled up to a bloc. In each case the tissue samples were taken from the experimental animals and from one control animal sacrificed at the same day. The sections were incubated in FITC-labelled anti-rabbit globulin goat serum at room temperature for 30 min in a moist chamber. For control of specificity were employed: a) initial incubation of equal sections with unlabelled anti-rabbit globulin goat serum for 30 min (""blocking test''), b) pancreatic tissue specimens of each one untreated control animal present in the cryostat sections and thus incubated like the pancreatic tissue of the experimental animals, c) native nonincubated cryostat sections from the same bloc to exclude nonspecific autofluorescence. Evaluation of the sections was done in a Zeiss-Lg-microscope with HBO-50 high pressure mercury lamp. Exciter filters were UG 1/3.5 and 1/1.5, the eyepiece was screened with a GG 9/1 filter photographs were taken on ORWO X-ray film RS 2 (VEB Filmfabrik Wolfen). The enzyme histochemical studies were performed on cryostat sections of the same tissue bloc using the following methods: lead nitrate- or calcium-Co-method after GOMORI (1952) for demonstration of acid and alkaline phosphatase, naphthylacetate method (NACHLAS and SELIGMAN 1945) for nonspecific esterase, MTT-co-method (PEARSE et al...

Cross-mating experiments with Boophilus annulatus and B. microplus (Acarina: Ixodidae).

Female Boophilus annulatus (Say) and B. microplus (Canestrini) mated readily with males of the other species when pairs were isolated in a small cell on a calf's back. The crossmated females engorged as readily as females that mated with their own species, the size and fecundity of the females were not altered by cross-mating, the hatch of the F1 eggs equaled that of colony strains of the 2 species, and the F1 hybrid progeny appeared normal in vigor and longevity. However, the eggs resulting from F1 brother × sister matings generally did not hatch. Backcrosses indicated that the sterility of hybrid males exceeded 99% and that the fertility of hybrid females was reduced. The caudal process of the hybrid males was usually intermediate in size between that of normal B. annulatus and B. microplus males. The 2 species are apparently closely related, probably sibling species, but reproductively isolated by sterility of hybrids.

Rapid incorporation of wild genotypes of Culex nigripalpus (Diptera: Culicidae) into laboratory-adapted strains.

Laboratory mating activities were analyzed in wild and colonized forms of Culex nigripalpus Theobald. Mating experiments utilizing colony females produced insemination levels of about 75% whereas in those experiments involving wild females the insemination rates were less than 2%. Mating success was independent of the type of male used in each cross. Wild genetic material was rapidly incorporated into colony strains via wild males crossed to colony females. This method was used to establish a laboratory marker strain which contains the mutant form, orange fat color.

Staphylococcusに関する研究

We studied nutrition requirements of small colony mutants ofStaph. aureus, that are resistant to 10, 000γ/ml of SM, and also the resistance against SM, of large colony strain arising out of reverse mutation, and obtained the following results.1. When cultured in the media containing hemoglobin, glutamic acid, glucose, glycerin, filtrate of live bacteria in culture, and filtrate of dead bacteria (killed by heating), there could be observed no accelerating action on the cell growth of these strains.2. When cultured in the common agar medium containing 1% hemoglobin, there arose large colonies by reverse mutation, and likewise when cultured in the common agar containing the filtrate of live bacteria in culture, there developed many large colony mutants. In the case cultured in common agar plate medium there could be recognized a few large colony mutants.3. We also attempted to restore the SM resistance of large colony mutant, namely, reverse-mutant strain, but could not recognize any change in the SM resistance.

Staphylococcusに関する研究

We studied nutrition requirements of small colony mutants ofStaph. aureus, that are resistant to 10, 000γ/ml of SM, and also the resistance against SM, of large colony strain arising out of reverse mutation, and obtained the following results.1. When cultured in the media containing hemoglobin, glutamic acid, glucose, glycerin, filtrate of live bacteria in culture, and filtrate of dead bacteria (killed by heating), there could be observed no accelerating action on the cell growth of these strains.2. When cultured in the common agar medium containing 1% hemoglobin, there arose large colonies by reverse mutation, and likewise when cultured in the common agar containing the filtrate of live bacteria in culture, there developed many large colony mutants. In the case cultured in common agar plate medium there could be recognized a few large colony mutants.3. We also attempted to restore the SM resistance of large colony mutant, namely, reverse-mutant strain, but could not recognize any change in the SM resistance.

Some observations on a streptomycin-dependent strain of Staphylococcus aureus.

SUMMARY: Variants whose growth was either dependent upon or enhanced by streptomycin appeared spontaneously during a sensitivity titration of a strain of Staphylococcus aureus isolated from a nose and throat culture. In addition to these variants, multiple single colony strains from the original culture exhibited a wide range of susceptibility to streptomycin. The variability after exposure to streptomycin in the laboratory was no greater than that exhibited by the original isolates. The mechanism by which these variants utilize streptomycin is not yet known. Streptomycin inactivated by semicarbazide or l-cysteine did not support or enhance growth. The acquisition of the ability to utilize streptomycin had no measurable effect on the other biochemical characteristics investigated. When large inocula of the dependent variant were planted on streptomyein-free agar, a few colonies appeared after prolonged incubation. The cells of such colonies underwent a profound morphologic change not unlike the production of ‘large bodies’ which occurs in several species of bacilli. The progeny of such colonies were of normal morphology and either resistant or susceptible to streptomycin but were no longer dependent on it. Survival of the variants in chick embryos, except in those instances where mutation occurred, was dependent upon the presence of streptomycin. These variants were mouse avirulent, even in the presence of hog mucin in addition to streptomycin.

Nuclear changes in Bacillus anthracis and their Relation to Variants

SUMMARY: The nuclear changes leading to spore formation in Bacillus anthracis were investigated in 35 strains. Fusion of four chromatinic bodies into one mass and its subsequent break up into four bodies was observed. One of these became incorporated in the spore; the other three disintegrated. Some cells showed no fusion before spore formation; in these one chromatinic body was incorporated in the spore and the other three disintegrated. The percentage of cells in which fusion occurred varied with the strain. Rough colony strains showing a high incidence of fusion tended readily to throw smooth colony variants. Strains showing a low incidence of fusion were stable in this respect. The incidence of variants of other types bore no relation to the incidence of nuclear fusion in the strain.

The Primary Isolation of Small Colony Strains of Eberthella Typhosa from Blood, Feces, Urine, and Sputum

reports of the isolation of small colony strains from disease processes. Chief among these is a report by Jacobsen' who cultured 50 specimens of blood and feces during an outbreak of typhoid fever in an insane asylum and obtained only 2 isolations. One of these from blood produced very fine colonies on agar, showed delayed acid reaction in mannite broth, and was not agglutinated by typhoid antiserum until after 4 months' cultivation on artificial mediums. From a feces culture plated on Conradi-Drigalski agar a second strain of E. typhosa was isolated which proved to be identical in its reactions with the first. Colonies were not visible at the end of 48 hours' incubation and were dis-

PATHOLOGIC CHANGE IN OLFACTORY NASAL MUCOSA OF ALBINO RATS WITH "STUNTED" OLFACTORY BULBS

The occasional occurrence of small olfactory bulbs in the albino rat has been noted by Holt,1Sugita2and Donaldson and Hatai3and in my previous study.4These bulbs, which occur rather infrequently in young rats and which were designated as stunted by Sugita, were found to be present in all the senile rats studied.4The fact that the decrease in volume was apparently dependent on the loss of the entering olfactory fibers led me to obtain some further material in order that the olfactory mucous membrane and olfactory nerves might be studied along with the olfactory bulbs. The results of this study form the basis of the present communication. MATERIAL AND METHODS Twelve male albino rats of the experimental colony strain were obtained from the Wistar Institute for this investigation. These were of the same stock as those used in a previous study and like them were all normal rats

Effect of Sodium Amytal on Leucocytes of the Albino Rat

Male rats of Wistar Experimental Colony strain were used in a study of the effect of sodium amytal upon the white blood cell counts. Preceding and during the experiment, these animals were under standardized and controlled conditions as previously described. The procedure was as follows: At 11, 12, and 13 (1 P.M.) o'clock wet counts for the total number of white cells per cc. of blood were made. At the same time smears were prepared for differential counts. Immediately after the 11 and 12 o'clock counts, saline solution was injected as a control. After the 13 o'clock count an aqueous solution of sodium amytal, 6 mg. per 100 gm. of body weight, was injected. Wet counts were made and smears prepared every 2 hours for the next 16 hours. Sixteen male rats were used in the experimental groups. The normal curve of 53 animals determined recently under identical conditions was accepted as control. The first 3 counts were used as a basis to determine the normal expectancy for each animal for each succeeding hour (based on the findings of previous work on the normal diurnal tide of the albino rat). Let X1, X2, —, X16, represent the actual blood count of each of the 16 animals at any given hour. Let Y1, Y2, —, Y16, represent the count normally expected for each animal for that hour had the drug not been administered. X1/Y1, X2/Y2, —, X16/Y16, then represent the ratio of actual to normal, or a measure of the effect of the drug at any time. Then equals the average measure of the effect, or gives a value by which the point on the normal curve must be multiplied in order to obtain the level of leucocytosis caused by the drug at a given hour.

The change in volume of the olfactory and accessory olfactory bulbs of the albino rat during postnatal life

AbstractTransverse sections of the olfactory bulbs were prepared for seventy‐one male and six female albino rats, all of which were of the Experimental Colony strain obtained from The Wiostar Institute. These were selected and grouped according to age so that representative ages throughout the whole of the postnatal life cycle are available.

Effects of Administration of Cortin to the Hypophysectomized Rat.

Among the results of experimental hypophysectomy in mammals are loss of weight, or, in young animals, failure to increase in weight, loss of libido sexualis, cessation of estrus, or sexual infantilism, lessened spontaneous activity, lowered metabolism and lowered temperature., , Autopsy of such animals shows atrophy of the thyroid, the adrenal cortex, the gonads, the secondary sex organs, and the thymus. It is apparent that the hypophysectomized animal is characterized not only by absence of the pituitary but also by a marked reduction in size, and presumably also in function, of several other highly important endocrine glands. Considerable light has been thrown on the respective rôles of the thyroid and the gonads in this complex endocrine disturbance., The functional relationships of the adrenal cortex in the above pictured syndrome are not so well known; what symptoms and what glandular deficiencies. if any, are secondary to the atrophy of this important endocrine gland following removal of the pituitary? We have previously reported the results of cortin treatment in hypophysectomized Amphibia. In our mammalian experiments albino rats weighing from 150-200 gm., principally from the Wistar experimental colony strain were used. Beginning about the 6th day following hypophysectomy certain animals received daily two 0.5 cc. injections of cortin. Other operated animals were injected at similar times with an equal amount of salt solution. Still other litter mates, unoperated, were available for controls. The operated animals were weighed and daily vaginal smears obtained from the females. In the latter part of the experiment spontaneous activity cages, which recorded revolutions, were available and some of the animals lived in them. The rats were killed from 4 to 8 weeks following operation after having received treatment for from 3 to 7 weeks.