1344 Assessment of Appropriateness of Red Flag Referrals to One Stop Breast Clinic in Antrim Area Hospital

Aim

To assess the appropriateness of red flag referrals to breast clinic.

Method

Retrospective study of patients attending breast clinic as red flag referrals within a few months period. 149 patients were identified. Their referrals and clinic notes were accessed through electronic care records. Out of the 149 patients used, 2 were routine referrals and the others were red flag. Various sources of referrals were seen such as from GP, Screening programme, SDA programme, and other departments.

Results

From the referrals, 95% are female (N = 142) and the remaining N = 7 (5%) were males. The youngest patient referred was 14 years old and the oldest 92. The average age for the referrals were 50 years old. From all the 125 referrals from GPs, 81.6% are in accordance with NI guideline and 78.4% are in accordance to NICE guidance. Of the 10 referrals made by other specialties, only 80% are in accordance with NICE and NI guidelines. The remaining 12 of the patients were from the SDA programme/ Breast screening programme. Interestingly of all the red flag referrals, only (9%, N = 13) are cancer.

Conclusions

Currently there is no triage system for red flag referrals in Antrim Area Hospital for breast clinic. We are currently seeing all the patients that are referred as red flag although some of them are inappropriate. A triage system needs to be placed.

An internal carotid artery aneurysm presenting with dysarthria

A 72-year-old woman presented to her general practitioner with a 4-week history of right neck swelling. Clinical examination elicited a pulsatile mass consistent with a carotid artery aneurysm. Five days later the patient noticed her tongue movements had become awkward with associated dysarthria. Computed tomography confirmed a 4cm internal carotid artery aneurysm arising just distally to the carotid bifurcation. She proceeded to transfemoral diagnostic carotid angiography. Balloon occlusion of the right internal carotid artery origin was performed for a ten-minute period without any neurological deficit.

The decision was taken to proceed to surgical ligation of the origin of the internal carotid artery. Her symptoms of dysarthria have resolved.

Vaccination of chickens with Salmonella Pathogenicity Island (SPI) 1 and SPI2 defective mutants of Salmonella enterica serovar Enteritidis

In this study we were interested in the vaccine potential of two attenuated mutants of Salmonella enterica serovar Enteritidis for poultry. The first mutant was attenuated by the removal of the whole Salmonella Pathogenicity Island 1 (SPI1) and the second mutant was devoid of the whole SPI2. These 2 mutants were used for oral vaccination of 2 chicken lines; Lohmann Brown and ISA Brown. Chickens were vaccinated orally on day 1 of life, revaccinated on day 21 and challenged on day 42. The challenge was performed either orally or intravenously. Despite a slightly different response between the two chicken lines, both the mutants gave protection to poultry against S. Enteritidis challenge as documented by findings such as the bacterial counts in tissues, spleen weight, antibody production and cytokine response (namely IL-17 and IL-22). When the 2 mutants were compared, vaccination with the SPI1 mutant proved to be more effective in the protection of poultry against S. Enteritidis challenge than the vaccination with the SPI2 mutant. On the other hand, vaccination with the SPI2 mutant stimulated a slightly higher antibody production and such a mutant might therefore be a better choice if Salmonella is used as a vector for the delivery of heterologous antigens with a desired stimulation of the humoral part of the immune system.

Long-term treatment with the dipeptidyl peptidase-4 inhibitor saxagliptin in patients with type 2 diabetes mellitus and renal impairment: a randomised controlled 52-week efficacy and safety study

OBJECTIVE

Therapeutic options are limited for diabetes patients with renal disease. This report presents 52-week results from a study assessing the dipeptidyl peptidase-4 inhibitor saxagliptin in patients with type 2 diabetes mellitus (T2DM) and renal impairment.

DESIGN

Double-blind study in patients stratified by baseline renal impairment (moderate, severe or end-stage renal disease [ESRD] on haemodialysis) randomised to saxagliptin 2.5 mg once daily or placebo added to other antidiabetic drugs in use at baseline, including insulin.

PATIENTS

A total of 170 adults with glycated haemoglobin (HbA(1c) ) 7-11% and creatinine clearance < 50 ml/min or ESRD were randomised and treated.

MEASUREMENTS

Absolute changes in HbA(1c) and fasting plasma glucose (FPG) from baseline to week 52 were evaluated using analysis of covariance (ANCOVA) with last observation carried forward. Repeated-measures analyses were also performed.

RESULTS

Adjusted mean decrease in HbA(1c) was greater with saxagliptin than placebo (difference, -0.73%, p < 0.001 [ANCOVA]). Reductions in adjusted mean HbA(1c) were numerically greater with saxagliptin than placebo in patients with renal impairment rated as moderate (-0.94% vs. 0.19% respectively) or severe (-0.81% vs. -0.49%), but similar to placebo for those with ESRD (-1.13% vs. -0.99%). Reductions in adjusted mean FPG were numerically greater with saxagliptin in patients with moderate or severe renal impairment. Saxagliptin was generally well tolerated; similar proportions of patients in the saxagliptin and placebo groups reported hypoglycaemic events (28% and 29% respectively).

CONCLUSIONS

Saxagliptin 2.5 mg once daily offers sustained efficacy and good tolerability for patients with T2DM and renal impairment.

Emergency and therapeutic vaccination--is stimulating innate immunity an option?

There is increasing evidence that activation of innate immunity, in animals and man, by live vaccines, sub-unit vaccines or synthetic or non-synthetic stimulants can induce a profound and rapidly induced resistance to pathogens, including infectious agents that are unrelated to the stimulating antigen or agent. We review the evidence for this phenomenon and present the proposition that this approach might be used to stimulate immunity during the life of the animal when susceptibility to infection is high and when normal vaccination procedures may be inappropriate.

Salmonella enterica serovar Typhimurium and Enteritidis infection of pigs and cytokine signalling in palatine tonsils

Pigs are considered as one of the major sources of zoonotic strains of Salmonella enterica for humans. Out of many S. enterica serovars, S. Typhimurium dominates in pigs, however, in several countries in Central Europe, S. Enteritidis is also quite frequent in pig herds. In this study we therefore compared the colonisation of pigs with S. Typhimurium and S. Enteritidis. We found that 3 weeks after infection S. Enteritidis 147 colonised the intestinal tract in higher quantities but was shed in faeces in lower quantities than S. Typhimurium 17C10. In a second experiment we found out that S. Enteritidis 147 and its SPI-1 and SPI-4 mutants increased proinflammatory cytokine (IL-1β and IL-8) signalling in the ileum 5 days post infection. On the other hand, independent of SPI-1 or SPI-4, S. Enteritidis 147 suppressed expression of IL-18, MCP1, TLR2, CD86, IL-7, IL-10 and IL-15 in the palatine tonsils. The suppression of cytokine signalling may facilitate the initial colonisation of the palatine tonsils by Salmonella. Moreover, immune suppression may also influence pig resistance to opportunistic pathogens and Salmonella infection in pigs thus may become an issue not only in terms of pork contamination but also in terms of affecting the immunological status of pig herds.

Saxagliptin improves glycaemic control and is well tolerated in patients with type 2 diabetes mellitus and renal impairment

AIM

To evaluate the efficacy and safety of saxagliptin vs. placebo in patients with type 2 diabetes mellitus (T2DM) and renal impairment.

METHODS

In this multicentre, randomized, parallel-group, double-blind, placebo-controlled study, patients with glycated haemoglobin (HbA1c) 7-11% and creatinine clearance <50 ml/min were stratified by baseline renal impairment (moderate, severe or end-stage on haemodialysis), and randomized (1 : 1) to saxagliptin 2.5 mg once daily or placebo for 12 weeks. Oral antihyperglycaemic drugs and insulin therapy present at enrolment were continued throughout the study. The absolute change in HbA1c from baseline to week 12 (primary efficacy end-point) was analysed using an analysis of covariance model with last observation carried forward methodology.

RESULTS

A total of 170 patients were randomized and treated. The adjusted mean decrease from baseline to week 12 in HbA1c was statistically significantly greater in the saxagliptin group than in the placebo group; the difference between treatments was -0.42% (95% confidence interval: -0.71 to -0.12%, p = 0.007). Adjusted mean HbA1c decreases from baseline to week 12 were numerically greater with saxagliptin than with placebo in the subgroups of patients with moderate (-0.64 vs. -0.05%) and severe (-0.95 vs. -0.50%) renal impairment. HbA1c reductions were similar between saxagliptin and placebo in the subgroup with end-stage renal disease on haemodialysis (-0.84 vs. -0.87%). Saxagliptin was generally well tolerated; incidences of adverse events and hypoglycaemic events were similar to placebo.

CONCLUSIONS

Saxagliptin 2.5 mg once daily is a well-tolerated treatment option for patients with inadequately controlled T2DM and renal impairment.

LPS structure influences protein secretion in Salmonella enterica

In this study we have compared protein secretion in the wild type of S. Typhimurium and the rfaC mutant. We found out that the rfaC mutant was defective in protein secretion. In addition, the rfaC mutant was defective in its invasion into an IPEC-J2 porcine epithelial cell line and also in motility in semisolid agar. Consistent with this, reduced flagella numbers were observed in the rfaC mutant. In the rfaC mutant, there were no defects in flagellin expression as detected by western blot and immune electron microscopy which demonstrated equal amounts of flagellin in the cytoplasm of both the rfaC mutant and the wild-type S. Typhimurium. However, in the wild-type strain only, the flagellin was assembled to spatially restricted areas on the inner side of cytoplasmic membrane. The oligosaccharide core of LPS is therefore required for the assembly of flagella and T3SS secretion machinery followed by protein secretion.

Comparative analysis of Salmonella enterica serovar Enteritidis mutants with a vaccine potential

If any new live Salmonella vaccine is introduced in the future, it is quite probable that detailed characterisation of its attenuation will be required. In this study we therefore compared 34 isogenic mutants of S. Enteritidis in aroA, aroD, galE, ssrA, sseA, phoP, rpoS, ompR, htrA, clpP, lon, rfaL, rfaG, rfaC, hfq, sodCI, hilA, sipA, avrA, sopB, sopA, sopE, sifA, shdA, fliC, fur, relA, spoT, rel-spoT, misL, rmbA, STM4258, STM4259 and spvBC genes for their resistance to stresses likely to be expected in the host and for their virulence and immunogenicity in Balb/C mice. We found that the cold and bile resistances essentially did not correlate with the resistances to other stress factors. Resistance to acid pH, heat, polymyxin and serum correlated with each other and also with the attenuation. When the residual virulence and immunogenicity were both considered, mutants in htrA, ompR, aroA, aroD and lon performed the best in mice. Furthermore, when a detailed comparison of polymyxin and serum sensitive mutants was performed, the serum sensitive mutants were more immunogenic.

Deletion of sodCI and spvBC in Salmonella enterica serovar Enteritidis reduced its virulence to the natural virulence of serovars Agona, Hadar and Infantis for mice but not for chickens early after infection

Salmonella enterica serovars Typhimurium, Enteritidis, Dublin, Choleraesuis or Gallinarum can colonise liver and spleen in particular hosts while infections with serovars Infantis, Agona, Hadar, etc. are usually limited to gastrointestinal tract. Reasons for this behavior are unknown, although it has been shown that sodCI and spv genes exhibit a strict distribution between more and less virulent serovars and they influence Salmonella virulence. However to what extent the presence or absence of these genes is associated with the increased virulence of serovars which possess them has never been addressed experimentally. In this study we therefore first confirmed the exclusive association of spvB and sodCI genes with the former group of serovars. In the next step we removed these two genes from S. Enteritidis genome and compared the virulence of such a mutant with the virulence of S. Infantis, S. Agona and S. Hadar for chickens and highly sensitive Balb/C mice. Single strain infection showed that the deletion of these two genes from S. Enteritidis resulted in the reduction of its virulence for mice but not for chickens. Mixed infection further confirmed these observations and indicated that in mice but not in chickens the virulence of sodCI and spv mutant was reduced to the natural virulence of serovars Infantis, Agona and Hadar. Although sodCI and spv genes do not influence S. Enteritidis virulence for chickens directly, they may be of an indirect effect through the increased persistence of S. Enteritidis in mice and increased probability of the reintroduction of S. Enteritidis into poultry flocks.

Unusual presentation of Kelley-Seegmiller syndrome

Female carriers of hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency have somatic cell mosaicism of HPRT activity and are healthy. We report a 50-year-old woman without gout or nephrolithiasis. She was never on allopurinol. Normal serum uric acid concentrations, increased plasma hypoxanthine, and xanthine were found. HPRT activity in erythrocytes was surprisingly low: at 8.6 nmol h(-1) mg (-1) haemoglobin. Mutation analysis revealed a heterozygous HPRT gene mutation, c.215A > G (p.Tyr72Cys). Assessment of X-inactivation ratio has shown that > 75% of the active X-chromosome bears the mutant allele and could explain these unusual, previously undescribed findings.

Characterization of Salmonella enterica serovar Typhimurium conjugative plasmids transferring resistance to antibiotics and their interaction with the virulence plasmid

OBJECTIVES

In this study, we analysed field isolates of Salmonella enterica serovar Typhimurium for the presence of conjugative plasmids transferring resistances to antibiotics.

METHODS

Altogether 23 strains were analysed for the presence of conjugative R-plasmids. In the case of successful conjugation, the R-plasmids were characterized by PCR for antibiotic resistance genes, integrons and replicon typing. Variable regions of integrons were sequenced.

RESULTS

Conjugation and transfer of antibiotic resistance was observed in 12 strains. Conjugative plasmids in these strains belonged to the IncI1 and IncHI1 replicons and four of them transferred antibiotic resistance associated with class I integrons. In two cases, resistance to tetracycline and/or ampicillin was not transferred by conjugation to approximately 10% of the transconjugants. Detailed characterization showed that the loss of both resistances was associated with the loss of Tn3 (bla(TEM)) and Tn1721 [tet(A)] from the conjugative plasmids p9046 and p9134. However, when only the tetracycline resistance was lost, the Tn1721 was replaced with a partial sequence of rck, and with complete coding sequences of srgA, srgB, ORF7 and pefI originating from the Salmonella Typhimurium virulence plasmid.

CONCLUSIONS

Two plasmids from our collection were capable of recombination with the virulence plasmid of Salmonella Typhimurium and subsequently spread both antibiotic resistance and virulence genes to the recipient.

Coated fatty acids alter virulence properties of Salmonella Typhimurium and decrease intestinal colonization of pigs

Salmonella Typhimurium infections in pigs are a major source of human foodborne salmonellosis. To reduce the number of infected pigs, acidification of feed or drinking water is a common practice. The aim of the present study was to determine whether some frequently used short- (SCFA) and medium-chain fatty acids (MCFA) are able to alter virulence gene expression and to decrease Salmonella Typhimurium colonization and shedding in pigs using well established and controlled in vitro and in vivo assays. Minimal inhibitory concentrations (MIC) of 4 SCFA (formic acid, acetic acid, propionic acid and butyric acid) and 2 MCFA (caproic and caprylic acid) were determined using 54 porcine Salmonella Typhimurium field strains. MIC values increased at increasing pH-values and were two to eight times lower for MCFA than for SCFA. Expression of virulence gene fimA was significantly lower when bacteria were grown in LB-broth supplemented with sub-MIC concentrations of caproic or caprylic acid (2 mM). Expression of hilA and invasion in porcine intestinal epithelial cells was significantly lower when bacteria were grown in LB-broth containing sub-MIC concentrations of butyric acid or propionic acid (10 mM) and caproic or caprylic acid (2 mM). When given as feed supplement to pigs experimentally infected with Salmonella Typhimurium, coated butyric acid decreased the levels of faecal shedding and intestinal colonization, but had no influence on the colonization of tonsils, spleen and liver. Uncoated fatty acids, however, did not influence fecal shedding, intestinal or tonsillar colonization in pigs. In conclusion, supplementing feed with certain coated fatty acids, such as butyric acid, may help to reduce the Salmonella load in pigs.

Biofilm formation in field strains of Salmonella enterica serovar Typhimurium: identification of a new colony morphology type and the role of SGI1 in biofilm formation

In this study we examined the extent of biofilm formation in field strains of Salmonella enterica serovar Typhimurium (S. Typhimurium), an important foodborne pathogen. Ninety-four field strains of S. Typhimurium were tested for their ability to form biofilm and components contributing to its formation. Most S. Typhimurium strains were highly capable of biofilm formation except for strains of phage type DT2 originating from pigeons. The most efficient biofilm forming strains were those of phage type DT104 positive for Salmonella genomic island 1 (SGI1). A comparison of SGI1 positive and negative strains indicated that the increased biofilm formation of SGI1 positive strains was associated with the presence of this genomic island. Finally, in five strains we found an alternative strategy of biofilm formation independent of curli fimbriae and cellulose production but solely dependent on an overproduction of capsular polysaccharide. Due to a mucoid and brown appearance on Congo Red agar we designated these strains as belonging to the SBAM (smooth brown and mucoid) morphotype.

Cytokine response of porcine cell lines to Salmonella enterica serovar typhimurium and its hilA and ssrA mutants

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a facultative intracellular bacterium which can infect and colonize pigs. After contact with enterocytes and macrophages, S. Typhimurium induces production of cytokines thus triggering the innate immune response. In this study we evaluated the cytokine response of two porcine cell lines, IPI-2I and 3D4/31, of epithelial or macrophage origins, respectively, to the wild-type S. Typhimurium and its hilA and ssrA mutants. We observed that the 3D4/31 cell line essentially did not respond to S. Typhimurium infection when a medium with foetal calf serum was used. However when the 3D4 cell line was incubated overnight in the presence of porcine serum, it efficiently responded to the wild-type strain and the ssrA mutant but not to the noninvasive hilA mutant as measured by mRNA quantification of TNF-alpha, IL-8 and GM-CSF by the real-time RT-PCR. In IPI-2I, all the cytokines were also induced by the wild-type S. Typhimurium and the ssrA mutant although the induction of TNF-alpha was lower than that induced by the wild-type strain. The hilA mutant was unable to induce any of the cytokines tested. The ssrA mutant can therefore be considered as more suitable for further vaccine development as the stimulation of innate immune response is important for animal protection against a challenge with virulent strains.

Ordered expression of virulence genes in Salmonella enterica serovar typhimurium

Using transcriptional promoter fusions, we investigated the expression of selected SPI-1 and SPI-2 genes of Salmonella enterica serovar Typhimurium (S. Typhimurium). Promoters of genes related to the invasion of the epithelial cell (hilA, hilC, hilD, invF, sicA, sopA, sopB and sopE2) were active in Luria-Bertani (LB) medium and LB with butyrate but were suppressed by bile salts and in glucose minimal (M9) medium. Genes related to S. Typhimurium intracellular survival (phoP, ssrA, ssaB, ssaG, sifA, sifB and pipB) were characterized by their expression in stationary phase in LB and M9 medium. Activity of phoP and ssrA promoters indicated that these might be expressed inside the gut. SPI-1 genes were expressed on the transition to stationary phase while SPI-2 genes were expressed in stationary phase. Among SPI-1 genes, those with regulatory functions preceded in expression the effector genes and sop genes were expressed in the order of sopA, sopB and sopE2, showing hierarchy in the expression of S. Typhimurium virulence genes.

Identification of putative ancestors of the multidrug-resistant Salmonella enterica serovar typhimurium DT104 clone harboring the Salmonella genomic island 1

The origin of multidrug-resistant Salmonella enterica serovar typhimurium (S. typhimurium) harboring the Salmonella Genomic Island 1 (SGI1), which was detected for the first time in the mid-1980s is unknown. In this study, we performed microarray genomotyping of four multidrug-resistant SGI1 positive strains and found that unlike the S. typhimurium LT2 strain, the multidrug-resistant strains lacked genes STM0517-0529 allowing the utilization of allantoin as a sole nitrogen source. We extended this observation by PCR screening of additional 120 S. typhimurium field strains and found that this locus was absent in all SGI1 positive and also in 24% of SGI1 negative strains, which were proposed to be the original recipients of SGI1. To prove this hypothesis, we compared the STM0517-0529 negative strains (with or without the SGI1) by PFGE and PCR prophage typing and found that 8 out of 11 of the SGI1 negative strains and 17 out of 22 SGI1 positive strains were of identical PFGE pattern and PCR prophage pattern, while this specific pattern was never observed among STM0517-0529 positive strains. We therefore propose that a lineage of the S. typhimurium DT104 sensitive strain first lost the ability to metabolize allantoin and then acquired SGI1.

Attenuated aroA Salmonella enterica serovar Typhimurium does not induce inflammatory response and early protection of gnotobiotic pigs against parental virulent LT2 strain

Cytokine and inflammatory response against virulent LT2 strain and its attenuated aroA deletion mutant of Salmonella enterica serovar Typhimurium were compared in gnotobiotic pigs. Contrary to the parental strain, the auxotrofic mutant did not induce IL-1beta, IL-18, TNF-alpha, and IFN-gamma in the ileum and plasma 24h after the infection, did not cause pathological changes in ileal epithelium and mesenteric lymph nodes or immunoreactivity of gp91 phox and peroxynitrite and was not immunostained for GroEL stress protein. The absence of induction of proinflammatory cytokines may be a reason why aroA mutant was unable to elicit any inflammatory response and protect pigs against challenge with virulent LT2 strain administered 24h later.

Vaccination and early protection against non-host-specific Salmonella serotypes in poultry: exploitation of innate immunity and microbial activity

A recent European Union Directive required member states to put monitoring and control programmes in place, of which vaccination is a central component. Live Salmonella vaccines generally confer better protection than killed vaccines, because the former stimulate both cell-mediated and humoral immunity. Administering Salmonella bacteria orally to newly hatched chickens results in extensive gut colonization and a strong adaptive immune stimulus but broiler chickens are immunologically immature. However, colonization exerts a variety of rapid (within 24 h) protective effects. These include specific colonization-inhibition (competitive exclusion) in which the protective bacteria exert a profound resistance to establishment and colonization by other related bacteria. This is thought to be primarily a metabolic attribute of the vaccinating bacteria but may also involve competition for attachment sites. The presence of large numbers of bacteria originating from a live Salmonella vaccine in the intestine can also induce infiltration of polymorphonuclear cells into the intestinal wall, which confers resistance to invasion and systemic spread by virulent Salmonella strains. This opens new perspectives for vaccine usage in broilers, layers and breeding poultry but also in other animals which show increased susceptibility to infection because of their young age or for other reasons, such as oral chemoprophylaxis or chemotherapy, where the lack of established normal gut flora is an issue. We recommend that all live vaccines considered for oral administration should be tested for their ability to induce the two protective effects described above. Further developments in live Salmonella vaccines are, however, currently hindered by fears associated with the use and release of live vaccines which may be genetically modified.

Distribution and function of plasmids in Salmonella enterica

Plasmids of Salmonella enterica vary in size from 2 to more than 200 kb. The best described group of plasmids are the virulence plasmids (50-100 kb in size) present in serovars Enteritidis, Typhimurium, Dublin, Cholerae-suis, Gallinarum, Pullorum and Abortus-ovis. They all encode spvRABCD genes involved in intra-macrophage survival of Salmonella. Another group of high molecular weight plasmids are plasmids responsible for antibiotic resistance. Since most of these plasmids are conjugative, besides storage of genetic information, they contribute to the spread of genes in bacterial populations. The low molecular weight plasmids are the last group of plasmids found in S. enterica. Some of them have been shown to increase resistance to phage infection due to the presence of restriction modification systems. Despite limited knowledge on their function, their presence or absence is frequently used for strain differentiation in epidemiological studies.

Medium-chain fatty acids decrease colonization and invasion through hilA suppression shortly after infection of chickens with Salmonella enterica serovar Enteritidis

The most common source of Salmonella infections in humans is food of poultry origin. Salmonella enterica serovar Enteritidis has a particular affinity for the contamination of the egg supply. In this study, the medium-chain fatty acids (MCFA), caproic, caprylic, and capric acid, were evaluated for the control of Salmonella serovar Enteritidis in chickens. All MCFA were growth inhibiting at low concentrations in vitro, with caproic acid being the most potent. Contact of Salmonella serovar Enteritidis with low concentrations of MCFA decreased invasion in the intestinal epithelial cell line T84. By using transcriptional fusions between the promoter of the regulatory gene of the Salmonella pathogenicity island I, hilA, and luxCDABE genes, it was shown that all MCFA decreased the expression of hilA, a key regulator related to the invasive capacity of Salmonella. The addition of caproic acid (3 g/kg of feed) to the feed of chicks led to a significant decrease in the level of colonization of ceca and internal organs by Salmonella serovar Enteritidis at 3 days after infection of 5-day-old chicks. These results suggest that MCFA have a synergistic ability to suppress the expression of the genes required for invasion and to reduce the numbers of bacteria in vivo. Thus, MCFA are potentially useful products for reducing the level of colonization of chicks and could ultimately aid in the reduction of the number of contaminated eggs in the food supply.

Intestinal colonisation-inhibition and virulence of Salmonella phoP, rpoS and ompC deletion mutants in chickens

Administration of live Salmonella strains to day-old chicks provides profound protection against superinfection with a related strain within a matter of hours by a colonisation-inhibition mechanism, which is primarily a bacterial physiological process. Although currently available, commercial, live attenuated Salmonella vaccines induce protection by adaptive immunity, none of them is able to induce protection against Salmonella organisms by colonisation-inhibition and, therefore, they are unable to protect newly-hatched birds immediately after oral vaccination. In this study, mutants of Salmonella Typhimurium and Enteritidis with deletions in phoP and rpoS, either alone or in combination with ompC, were characterised and tested for their level of attenuation and their ability to inhibit the intestinal colonisation of the isogenic parent strains in chickens. Mutants with deletions only in rpoS demonstrated an unaffected potential to inhibit the intestinal colonisation of the challenge strain but were still fully virulent for the chickens. Mutants with deletions in phoP, either alone or in combination with rpoS, resulted in a high level of attenuation, unimpaired ability to colonise the gut and a nearly unaffected potential to inhibit the challenge strain from caecal colonisation. Mutants with an additional deletion in ompC revealed a reduced capacity of intestinal colonisation-inhibition when compared to the control strains and both the single rpoS and the phoP deletion mutants. Mutations in phoP- or phoP-regulated genes may therefore be used for the development of live attenuated Salmonella vaccines possessing these novel characteristics.

Evolution of antibiotic resistance in Salmonella enterica serovar typhimurium strains isolated in the Czech Republic between 1984 and 2002

In a collection of 66 Salmonella enterica serovar Typhimurium strains isolated between 1984 and 2002 in the Czech Republic, genes coding for antibiotic resistance were determined by using specific PCRs. We found that the pentadrug-resistant ACSSuT clone first appeared in the Czech Republic in 1990. A new variant of the aadA gene designated aadA21 is described, the 5' end of which was identical to aadA2 and the 3' end of which was identical to aadA1.

[Specificity of inhibition between Salmonella strains]

A phenomenon of inhibition among Salmonella organisms colonizing the gut of young animals can be demonstrated which is important in connection with immunization using live Salmonella vaccines. For practical utilization of this inhibition phenomenon, research into its specificity is very important. In vitro broth culture and animal experiments have shown inhibition to be genus-specific, i.e. there is no inhibition between strains of different genera of Enterobacteriaceae in most cases. The strongest inhibition occurs between isogenic (identical genotype) strains (strain-specific inhibition). This applies to Salmonella and other genera of Enterobacteriaceae. There was a close correlation between the degree of the inhibitory effect and the genetic relatedness of the strains, as has been demonstrated in Salmonella strains of different epidemiological classification. The inhibitory capacity was most pronounced among closely related strains. Clonal strains of Salmonella Enteritidis phage type 4 fully inhibited caecal colonization by Salmonella Enteritidis phage type 4 strains in 65% of the combinations tested in chicks. In broth culture experiments, the share of combinations with complete inhibition was above 90%. A significant inhibitory competence of a selected strongly inhibitory Salmonella Enteritidis phage type 4 strain against the majority of Salmonella Enteritidis field isolates can be expected. However, Salmonella Enteritidis strains of all phase types showed almost no inhibitory competence against other Salmonella serotypes.

Low-molecular-weight plasmid of Salmonella enterica serovar Enteritidis codes for retron reverse transcriptase and influences phage resistance

Retron reverse transcriptases are unusual procaryotic enzymes capable of synthesis of low-molecular-weight DNA by reverse transcription. All of the so-far-described DNA species synthesized by retron reverse transcriptases have been identified as multicopy single-stranded DNA. We have shown that Salmonella enterica serovar Enteritidis is also capable of synthesis of the low-molecular-weight DNA by retron reverse transcriptase. Surprisingly, Salmonella serovar Enteritidis-produced low-molecular-weight DNA was shown to be a double-stranded DNA with single-stranded overhangs (sdsDNA). The sdsDNA was 72 nucleotides (nt) long, of which a 38-nt sequence was formed by double-stranded DNA with 19- and 15-nt single-stranded overhangs, respectively. Three open reading frames (ORFs), encoded by the 4,053-bp plasmid, were essential for the production of sdsDNA. These included an ORF with an unknown function, the retron reverse transcriptase, and an ORF encoding the cold shock protein homologue. This plasmid was also able to confer phage resistance onto the host cell by a mechanism which was independent of sdsDNA synthesis.

Flow cytometry characterisation of Salmonella typhimurium mutants defective in proton translocating proteins and stationary-phase growth phenotype

We have shown that the growth, starvation and population heterogeneity of Salmonella typhimurium and its isogenic nuoG and cydA mutants can be monitored by flow cytometry. Bacterial cells were analysed unstained, and after staining with rhodamine 123, propidium iodide and acridine orange. In unstained cultures it was possible to distinguish flagellated and non-flagellated cells. nuoG and cydA mutants were less stained with rhodamine confirming their defects in generating membrane potential. Increase in propidium iodide staining associated with reduced membrane integrity was seen between day 4 and 14 in all the strains. Acridine orange staining showed that there was retarded development in stationary phase in nuoG and cydA mutants. Furthermore, up to day 28, a small portion of cells showed high RNA and DNA levels. To determine whether these cells represent a sub-population better adapted for long term survival, we measured the growth of the population by both OD values and viable counts. Because the OD values increased throughout the whole study in both wild-type and mutant strains, while the viable counts gradually decreased, we propose that even in very old cultures there must be a population of cells undergoing replication.

Subdivision of Salmonella enterica serovar enteritidis phage types PT14b and PT21 by plasmid profiling

We have shown that plasmid profiling is a sensitive method for further identification of strains of Salmonella enterica serovar enteritidis (S. enteritidis) phage type PT21 and to a lesser extent the strains of phage type PT14b. Five and three plasmid types were identified within 33 strains of phage type PT21 and 19 strains of phage type PT14b, respectively. Plasmid types in strains of phage type PT21 showed significant correlation with geographical origin of the strain. In strains of phage type PT14b a single isolate predominated suggesting that the plasmid designated as 'C' can be directly linked with S. enteritidis PT14b strains. Application of IS200 fingerprinting did not reveal any other differences and showed just one copy of IS200 in all the 52 analysed strains. All the strains were tested for antibiotic resistance and only four strains were resistant to ampicillin, cefotaxime, cefuroxime and cotrimoxazole. This indicates that low molecular weight plasmids in Salmonella enteritidis are not responsible for the spread of antibiotic resistance.

Relationship between IS901 in the Mycobacterium avium complex strains isolated from birds, animals, humans, and the environment and virulence for poultry

A total of 738 strains of Mycobacterium avium complex (MAC) were examined in biological experiments on poultry by use of PCR methods with primers for detection of the insertion sequence IS901. Serotype strains of MAC from all known 28 serotypes were examined. Further strains were isolated from human immunodeficiency virus (HIV)-negative and HIV-positive patients, 6 animal species, 17 bird species, and the environment. Of 165 strains virulent for poultry, characterized by generalized tuberculosis, 164 strains contained IS901, a result which is statistically highly significant (P, 0.01). The remaining 573 strains were nonvirulent; however, IS901 was present in 24 strains. From among 20 strains of serotypes 1, 2, and 3, IS901 was found in 15 strains, only 5 of which were virulent for poultry. The remaining 111 strains, of serotypes 4 to 28, were nonvirulent and did not incorporate IS901. None of the 152 strains isolated from humans was virulent for poultry, including 12 strains which were IS901 positive.

Long term treatment of IgA nephropathy with cyclosporine A

20-50% of patients with IgA nephropathy (IgAN) reach end-stage renal failure. Yet a standard treatment for those with progressive course and/or great proteinuria is lacking. We treated 6 patients with biopsy proven IgAN, proteinuria over 3.5 g/24 h and S-creatinine less than 200 micromol/L non-responding to corticosteroids administered for 3 months. They were given cyclosporine A (CsA) 5 mg/kg bw/day then titrated aiming at a serum concentration of 70-150 ng/mL for one year tapered to discontinuation in 9 months. Prednisone 5-10 mg on alternate days was given with CsA. Proteinuria (g/day) decreased from 4.66 +/- 0.43 to 1.38 +/- 0.29 (p < 0.01) after 1 month and to 0.59 +/- 0.14 (p < 0.001) after 1 year of treatment and remained lower than baseline 2 years from the beginning (1.44 +/- 0.27, p < 0.001). GFR (creatinine clearance) did not change during the first month (1.25 +/- 0.21 mL/s vs 1.38 +/- 0.29 mL/s), but decreased after 1 year (1.05 +/- 0.14 mL/s, p < 0.05). After two years it increased to 1.17 +/- 0.16, NS from baseline. We also calculated the ratio of proteinuria to the GFR (mg/L) to assess the role of hemodynamic changes in the decrease of proteinuria. This ratio was 53.80 + 6.47 before therapy, it decreased after 1 month (11.56 +/- 1.7, p < 0.05) and further after 1 year (6.78 + 1.45, p < 0.01). Three months after discontinuation it was still 14.32 +/- 1.00, p < 0.05 from baseline. In conclusion, CsA significantly lowered moderate to high proteinuria in 6 patients with IgAN. Significant decrease of the proteinuria/GFR ratio suggests some non-hemodynamic mechanism of CsA action. The therapy was well tolerated and side-effects were not so severe as to require CsA withdrawal.

Standardisation of restriction fragment length polymorphism analysis for Mycobacterium avium subspecies paratuberculosis

DNA from 1008 strains of Mycobacterium avium subspecies paratuberculosis, digested by restriction endonucleases PstI and BstEII, was hybridised with a standard IS900 probe prepared by PCR and labelled non-radioactively by ECL. DNA fingerprints were scanned by CCD camera and analysed using the software Gel Compar (Applied Maths, Kortrijk, Belgium). Thirteen restriction fragment length polymorphism (RFLP) (PstI) types were detected, which where designated as A, B, C, D, E, F, G, H, I, J, K, L and M in accordance with the study of Pavlik et al. (1995) [Pavlik, I., Bejckova, L., Pavlas, M., Rozsypalova, V., Koskova, S., 1995. Characterization by restriction endonuclease analysis and DNA hybridization using IS900 of bovine, ovine, caprine and human dependent strains of Mycobacterium paratuberculosis isolated in various localities. Vet. Microbiol. 45, 311-318]. Twenty RFLP (BstEII) types were detected and designated as C1-3, C5, C7-20, S1 and I1 in accordance with the study by Collins et al. 1990 [Collins, D.M., Gabric, D.M., de Lisle, G.W., 1990. Identification of two groups of Mycobacterium paratuberculosis strains by restriction endonuclease analysis and DNA hybridization. J. Clin. Microbiol. 28, 1591-1596]. A combination of both RFLP (PstI) and RFLP (BstEII) results revealed a total of 28 different RFLP types. All the RFLP types and detailed protocols are available at Intemet web site WWW...: http:/ /www.vri.cz/wwwrflptext.htm.

Clinical features and natural history of IgA nephropathy

IgA nephropathy (IgAN) is the most common form of glomerulonephritis worldwide. It is characterized by recurrent gross hematuria, microhematuria and/or proteinuria and diffuse mesangial IgA deposits in glomeruli. It is predominantly a disease of young males. Apart from primary IgAN (Berger's disease), IgA deposits in the glomeruli are also seen in Henoch-Schönlein purpura and in association with various of other diseases, particularly liver cirrhosis. Originally it was thought that IgAN was a benign disease, but it is now known that approximately 20-40% of patients develop progressive renal disease 5 to 25 years after diagnosis and progress to end-stage renal disease. Clinical predictors of progressive disease are elevated serum creatinine concentration at presentation, increased systemic blood pressure, persistent protein excretion > 1.0 g/day and histological predictors are glomerulosclerosis, tubular atrophy/interstitial fibrosis, extension of immune deposits to the perivascular space and crescent formation. Progression correlates more closely with the severity of tubulointerstitial lesions than with the degree of glomerular lesions. These features of IgAN reported in literature were mostly, but not completely, confirmed by analysis of all consecutive patients with biopsy proven IgAN and follow-up > 12 months in the renal units of Heidelberg and Prague using univariate analysis, multiple range test and multiple regression analysis.

Diabetes--renal function--what are the special problems?

Diabetic nephropathy has become the single most important cause of endstage renal failure in most countries of the Western world. Against this background, the role of the renin-angiotensin system (RAS) and its blockade command considerable interest. In diabetic patients and in diabetic animals, the circulating components of the RAS are suppressed. Although the evidence is not completely uniform, there are indirect arguments (renal hemodynamic response to RAS blockade, AT1 receptor expression), however, which would be consistent with increased intrarenal action of angiotensin (ANG) II. There is solid evidence that ACE inhibitors effectively interfere with progression of micro-albuminuria both in IDDM and NIDDM. They also prevent progression of advanced renal failure in IDDM, while there is only preliminary evidence in this respect for NIDDM. ACE inhibitors are superior to conventional antihypertensive agents (with the possible exception of some calcium channel blockers), but such superiority is seen only when the levels of blood pressure are relatively high. In diabetic animals, treatment with ANG II receptor blockers interferes with the development of glomerular lesions. In acute and subacute studies on diabetic patients, ANG II receptor blockers reduced albuminuria (or proteinuria) more than beta-blockers. Head-on comparison of equipotent doses ACE inhibitors and ANG II receptor blockers in non-diabetic patients produced equal reductions in proteinuria. The long-term effects of ANG II receptor blockers on progression of advanced diabetic nephropathy is the object of two large international studies. The results will not be available before the year 2000.

Computer-assisted restriction endonuclease analysis of plasmid DNA in field strains of Salmonella enteritidis

Computer-assisted restriction endonuclease analysis of plasmid DNA in field strains of Salmonella enterica serovar Enteritidis (S. enteritidis) is described. The procedure consists of plasmid DNA purification, its digestion with restriction endonuclease TaqI, electrophoresis, charge-coupled device camera scanning of the gels, and an analysis of the restriction patterns with the software Gel Manager. The system allowed us to analyse, in detail, results of plasmid profiling in more than 600 field strains of S. enteritidis. In addition to plasmid-free and virulence plasmid only containing strains, 15 additional plasmid types were detected. All the images and detailed protocols are available at the Web site http://www.clark.cz/vri/salmon.htm.

The presence of genes homologous to the K88 genes faeH and faeI on the virulence plasmid of Salmonella gallinarum

A Tn3 insertion mutation was produced in the virulence plasmid of a strain of Salmonella gallinarum which conferred avirulence by parenteral and oral routes but which was also less invasive following oral inoculation. The transposon was found to have inserted near an open reading frame (ORF) with no homologies in the data banks. This ORF was adjacent to two additional ORF's with a high degree of homology of Escherichia coli genes encoding the minor structural subunits (FaeH and FaeI) of the K88 fimbria. A similar region of homology was found by DNA-DNA hybridization on the virulence plasmids of S. pullorum, S. dublin and other S. gallinarum strains but not in the plasmids of S. typhimurium, S. enteritidis or S. choleraesuis.

Peptidyl transferase activity in wheat germ ribosomes. Effect of some antibiotics

The formation of N-acetyl-leucyl-puromycin in a "fragment reaction" catalyzed by 80 S ribosomes from wheat germ was characterized. The reaction product was identified by high-voltage electrophoresis. The fragment reaction is inhibited by sparsomycin, blasticidin S, gougerotin and to a lesser degree by amicetin and tetracycline. Formation of an acLeu-pentanucleotide-ribosomes complex was strongly stimulated by sparsomycin.