Lactobacilli and acidosis in children with short small bowel

BACKGROUND

In patients with a short small bowel, D-lactic acidemia and D-lactic aciduria are caused by intestinal lactobacilli. The purpose of this study was to obtain a detailed picture of the metabolic acidosis in young children with short small bowel.

METHODS

Feces, blood, and urine of children with short small bowel and acidosis were studied microbiologically and/or biochemically.

RESULTS

Previous findings were confirmed that more than 60% of the fecal flora of patients with small short bowel, who are not receiving antibiotics, consists of lactic acid-producing lactobacilli. In blood, D-lactic acid was the most prominent metabolite: the highest serum D-lactate (15.5 mmol/l) was observed in a sample taken immediately after the onset of hyperventilation. The highest D-lactate excretion was in urine collected some hours after the onset of hyperventilation, and amounted to 59 mol/mol creatinine. Acidosis in the patients with short small bowel was related to strongly increased serum D-lactate and anion gap and to strongly decreased serum bicarbonate and pH.

CONCLUSION

In children with small short bowel and acidosis, the common intestinal flora of mainly lactobacilli abundantly produces D-lactic acid from easily fermentable carbohydrates. Thus, these bacteria directly cause shifts of bicarbonate, pH, and base excess and indirectly cause shifts of the anion gap, as well as hyperventilation. These kinetic parameters are strongly associated.

Prevalence of "syndrome X" features in parents of type 1 diabetic patients with or without nephropathy

OBJECTIVE

To compare the prevalence of "syndrome X"-related parameters in parents of type 1 diabetic patients with diabetic nephropathy (DNP) to those in parents of diabetic patients without DNP.

RESEARCH DESIGN AND METHODS

In this cross-sectional study, we included 50 parents of type 1 diabetic patients with DNP and 50 parents of diabetic patients without DNP. All parents were investigated in a fasting state for serum lipids including nonesterified fatty acids (NEFAs), glucose, HbA1c, plasma uric acid, fasting insulin levels, and albuminuria. Blood pressure was recorded in the supine position using an automatic device; ankle/brachial index was measured with Doppler ultrasound. Presence of cardiovascular disease was determined by a standardized questionnaire and electrocardiogram registration. Subjects without known diabetes underwent a 2-h oral glucose tolerance test. Anthropometric parameters such as BMI, waist-to-hip ratio, and percentage of body fat were measured. In addition to univariate analysis, a syndrome X score (SXS) was formulated, comprising a number of syndrome X-related biochemical, physiological, and/or anthropometric parameters.

RESULTS

Univariate analysis revealed no significant differences in syndrome X parameters between parents of type 1 diabetic patients with or without DNP. Also, the composite SXS was similar in both groups.

CONCLUSIONS

In this study, no differences were found in the prevalence of syndrome X features between parents of type 1 diabetic patients with DNP and parents of patients without DNP.

PCR detection of Coxiella burnetii from different clinical specimens, especially bovine milk, on the basis of DNA preparation with a silica matrix

For PCR detection of Coxiella burnetii in various clinical specimens we developed a sample preparation method in which silica binding of DNA was used. This method was found to be fast, easily performed with large numbers of samples, and equally sensitive for all of the specimens tested (livers, spleens, placentas, heart valves, milk, blood). The DNA preparation method described here can also be used as an initial step in any PCR-based examination of specimens. The procedure was tested with more than 600 milk samples, which were taken from 21 cows that were seropositive for C. burnetii and reportedly had fertility problems (and therefore were suspected of shedding the agent through milk intermittently or continuously). Of the 21 cows tested, 6 were shedding C. burnetii through milk. Altogether, C. burnetii DNA was detected in 6% of the samples. There was no correlation between the shedding pattern and the serological results.

Physical and genetic map of the obligate intracellular bacterium Coxiella burnetii

Pulsed-field gel electrophoresis and PCR techniques have been used to construct a NotI macrorestriction map of the obligate intracellular bacterium Coxiella burnetii Nine Mile. The size of the chromosome has been determined to be 2,103 kb comprising 29 NotI restriction fragments. The average resolution is 72.5 kb, or about 3. 5% of the genome. Experimental data support the presence of a linear chromosome. Published genes were localized on the physical map by Southern hybridization. One gene, recognized as transposable element, was found to be present in at least nine sites evenly distributed over the whole chromosome. There is only one copy of a 16S rRNA gene. The putative oriC has been located on a 27.5-kb NotI fragment. Gene organization upstream the oriC is almost identical to that of Pseudomonas putida and Bacillus subtilis, whereas gene organization downstream the oriC seems to be unique among bacteria. The physical map will be helpful in investigations of the great heterogeneity in restriction fragment length polymorphism patterns of different isolates and the great variation in genome size. The genetic map will help to determine whether gene order in different isolates is conserved.

Molecular characterization of Coxiella burnetii isolates

Restriction fragment length polymorphism (RFLP) was used for the differentiation of 80 Coxiella burnetii isolates derived from animals and humans in Europe, USA, Africa and Asia. After NotI restriction of total C. burnetii DNA and pulsed field gel electrophoresis (PFGE) 20 different restriction patterns were distinguished. The index of discrimination for this typing system was 0.86. Comparison and phylogenetic analysis of the different RFLP patterns revealed evolutionary relationships among groups that corresponded to the geographical origin of the isolates. This finding was confirmed by genetic mapping. No correlation between restriction group and virulence of isolates was detected.

Plasmid-homologous sequences in the chromosome of plasmidless Coxiella burnetii Scurry Q217

Chromosomal DNA from Coxiella burnetii Scurry Q217 was screened for the presence of plasmid-homologous sequences. Total DNA from Scurry Q217 was digested with NotI, and the resulting DNA fragments were separated by contour-clamped homogeneous electric field pulsed-field gel electrophoresis (CHEF-PFGE). Following hybridization with biotin-labeled QpH1 plasmid as a probe, two DNA fragments of 40 and 170 kb were identified as targets. These fragments were cloned, and subclones containing QpH1-homologous sequences were completely sequenced. The physical mapping of DNA fragments was achieved by PCR with primers derived from adjacent fragments, and a total of 18,360 bp was sequenced. Within the QpH1-homologous region spanning 16,624 bp, homology was as high as 99%. Deletions were identified within EcoRI fragments A(H)-C(H)-K(H)-B(H) (13,490 bp) and J(H)-G(H)-E(H)-L+-D(H) (6,509 bp) and in fragment A(H) alone (619 bp). An insertion of 744 bp was identified within the JDc region of Scurry Q217. A search for putative coding regions identified a total of 17 open reading frames (ORFs). Compared to plasmid QpH1, 6 ORFs were identical, 5 ORFs were different in size, 6 ORFs were newly generated, and 25 ORFs were lost. It was found that plasmid-homologous sequences in Scurry Q217 were of chromosomal origin.

Molecular characterization of Mycobacterium paratuberculosis isolates from sheep, goats, and cattle by hybridization with a DNA probe to insertion element IS900

Mycobactin J-dependent mycobacterial isolates from sheep, goat, and cattle herds with Johne's disease in Morocco, South Africa, the United States, and Germany were tested for the repetitive insertion sequence IS900 of Mycobacterium paratuberculosis by PCR. The IS900 PCR target sequence was detected in 90 of 93 fecal culture isolates tested (96.8%). Restriction fragment length polymorphisms (RFLPs) and in vitro growth characteristics were studied in 46 of the IS900-positive isolates and in two bovine vaccine strains of M. paratuberculosis. Five different RFLP types were identified in PvuII digests of genomic DNA by Southern hybridization with a DNA probe specific for IS900. All isolates of M. paratuberculosis could be classified into two major clusters by their growth rates as well as the relatedness of their PvuII-RFLP hybridization patterns. All of the sheep isolates were classified into cluster I (extremely slow growth), while all cattle and goat isolates were members of cluster II (moderately slow growth). Different PvuII-RFLP patterns were detected in different sheep flocks from Morocco and South Africa. Our results demonstrate that genetically and phenotypically different strains of M. paratuberculosis were present in ruminant populations. The strains from sheep in Morocco and South Africa tested in the study appeared to belong to a unique group of M. paratuberculosis strains that might have adapted to this host species. The presence of several genetically distinct strains in different sheep flocks suggested that analysis of IS900-specific RFLP patterns may provide a useful tool for the epidemiologic investigation of ovine paratuberculosis outbreaks.

Quantification of Coxiella burnetii by polymerase chain reaction (PCR) and a colorimetric microtiter plate hybridization assay (CMHA)

A colorimetric microtiter plate hybridization assay (CMHA) for the quantitative determination of Coxiella burnetii DNA after amplification by externally controlled polymerase chain reaction (PCR) is described. The quantification assay is based on an enzyme linked immunosorbent assay (ELISA) format. Cloned DNA, representing a sequence complementary to an internal part of the diagnostic amplicon, was noncovalently attached to the wells of a microtiter plate. Biotinylated PCR product was hybridized to the immobilized capture probe. Bound product was detected via streptavidin horse-radish peroxidase. The devised nonisotopic technique allows specific, rapid, and convenient quantification of C. burnetii DNA. Additionally, it is compatible with standard laboratory ELISA equipment, making this assay amenable to automation and permitting processing of large sample numbers.

Sequencing and linkage analysis of a Coxiella burnetii 2.1 kb NotI fragment

Most of the Coxiella burnetii isolates (72 of 80) available in our institute share a 2.1 kb NotI fragment. Sequence analysis revealed two incomplete open reading frames (ORF) for putative genes hemA and bcR coding for glutamyl-tRNA-reductase and bicyclomycin resistance protein, respectively. Upon completing the ORF for the hemA gene by sequencing the adjacent NotI/EcoRI fragment a third ORF for the putative prfA gene was determined coding for release factor 1, an enzyme catalysing the last step in protein biosynthesis.

D-lactic acidemia and aciduria in pediatric and adult patients with short bowel syndrome

D-Lactate produced by abundant intestinal lactobacilli during acidotic episodes in short bowel (SB) patients is commonly regarded as a main factor in the pathogenesis of SB syndrome-associated (D-lactic) acidosis. Since we had observed that gram-positive bacteria, mainly lactobacilli, were abundant even in the absence of acidosis, we studied serum concentrations and urinary excretions of D- and L-lactate in young and adult SB patients, especially during nonacidotic periods. Serum L-lactate and urinary L-lactate excretion were similar in adults and children. Serum D-lactate and urinary D-lactate excretion were higher in SB children than in SB adults. Food consumption affects D-lactate production and alters D-lactic acidemia and aciduria. We conclude that D-lactate is frequently present in serum of SB patients even in the absence of acidosis. High serum concentrations and urinary excretions may reflect dietary factors in these patients.

D-lactic acidemia and aciduria in pediatric and adult patients with short bowel syndrome

D-Lactate produced by abundant intestinal lactobacilli during acidotic episodes in short bowel (SB) patients is commonly regarded as a main factor in the pathogenesis of SB syndrome-associated (D-lactic) acidosis. Since we had observed that gram-positive bacteria, mainly lactobacilli, were abundant even in the absence of acidosis, we studied serum concentrations and urinary excretions of D- and L-lactate in young and adult SB patients, especially during nonacidotic periods. Serum L-lactate and urinary L-lactate excretion were similar in adults and children. Serum D-lactate and urinary D-lactate excretion were higher in SB children than in SB adults. Food consumption affects D-lactate production and alters D-lactic acidemia and aciduria. We conclude that D-lactate is frequently present in serum of SB patients even in the absence of acidosis. High serum concentrations and urinary excretions may reflect dietary factors in these patients.

Detection of Coxiella burnetii in cow's milk using the polymerase chain reaction (PCR)

A PCR approach (transposon PCR) with primers based on repetitive transposon-like sequences, which--depending on the isolate--were found at a minimum frequency of 19 on the C. burnetii genome, was established for the highly sensitive and specific detection of C. burnetii. This study describes the analytical detection of C. burnetii in milk, which requires a special preparation method prior to PCR. Because of the low level of C. burnetii particles in milk samples, template DNA was concentrated by a factor of 200, using cetyltrimethylammonium bromide as the precipitation reagent. Using this particular preparation method, even a single C. burnetii particle could be detected in 1 ml milk.

Analysis of the entire nucleotide sequence of the cryptic plasmid QpH1 from Coxiella burnetti

The complete plasmid QpH1 from Coxiella burnetti, isolate 'Nine Mile', phase I, was cloned as NotI fragment with a size of 37329 bp. The entire plasmid was sequenced by the chain termination method after EcoRI subcloning. 37 open reading frames coding for polypeptides larger than 100 amino acid residues were determined. The predicted polypeptide products of the open reading frames were compared by computer analysis with reported protein sequences. Homologies of predicted polypeptide products to analogous proteins are described.

Is plasmid based differentiation of Coxiella burnetii in 'acute' and 'chronic' isolates still valid?

Ten human Coxiella burnetii isolates from french patients with acute hepatitis or chronic endocarditis were characterized according to their polymorphism in DNA restriction patterns and differentiated by plasmid-specific PCR. The aim of this investigation was to clarify if the present classification of so called 'acute' and 'chronic' Coxiella burnetii isolates--based on plasmid profile of a so far limited number of partly ancient isolates--could be confirmed with lately isolated organisms of this agent. The data obtained in this investigation indicate that this classification based on C. burnetii plasmid content is no longer justified.

The 16S/23S ribosomal spacer region of Coxiella burnetti

The 16S/23S spacer region of Coxiella burnetti isolate Nine Nile, phase 1, was sequenced. Sequence analysis revealed two tRNA coding regions for tRNA(Ile) and tRNA(Ala). DNA sequence alignment demonstrated significant homology with tRNA species from Pseudomonas aeruginosa and Rhodobacter sphaeroides, respectively. The non-coding tRNA spacer region was unique to Coxiella burnetti, based on database alignment.

Use and costs of antimicrobial drugs in medical wards of a central hospital in Malawi

Economic constraints experienced by many African countries make it vital that reliable information is collected about the cost of patient care in health institutions. Case files and treatment charts of 509 patients admitted to non-fee paying medical wards of Queen Elizabeth Central Hospital, Blantyre, Malawi for the month of September 1992 were analysed in order to determine the amount and costs of drugs and antimicrobial agents given to inpatients. Infectious diseases accounted for 76% of all admissions. A total of 59 different drug items were used (cost U.S. $732). In all, 18 antimicrobial agents were given (31% of all drug items) at a cost of U.S. $615 (84% of all drug costs). Calculated costs of antimicrobial agents for each patient and for annual admissions (10325 in 1992) were U.S. $1.21 and U.S. $12,558 respectively. Although the present study has its limitations, it provides a rational basis for planning departmental drug budgets.

Polymorphism in DNA restriction patterns of Coxiella burnetii isolates investigated by pulsed field gel electrophoresis and image analysis

Pulsed field gel electrophoresis was used for differentiation of Coxiella burnetii isolates derived from animals in Europe and one from Namibia. Previously published data on isolates from North America demonstrated four groups with distinct banding patterns. Fingerprints of prototype isolates as references confirmed four different cleavage patterns upon NotI restriction of total DNA as described. With isolates available at our institute five additional DNA banding patterns were obtained from European and one Namibian isolate after endonuclease restriction with NotI. To compare patterns from different electrophoretic runs more precisely an image analysis system was used.

Plasmid based differentiation and detection of Coxiella burnetii in clinical samples

A "nested" PCR approach with primers based on conserved plasmid sequences was used for the highly sensitive and specific detection of Coxiella (C.) burnetii in clinical samples collected from cattle, dogs, cats and humans. Results were in good agreement with those obtained from Capture-ELISA and isolation of the organism in BGM cell culture. We also tested primers with sequences derived from genomic DNA and sequences based on 16S rRNA. In addition, we applied PCR for the differentiation of C. burnetii plasmid types from 28 isolates originating from the USA, Europe and South Africa. Reference isolates Nine Mile RSA493, Dugway 5J108-111 and all European isolates tested were recognized only by primers specific for the QpH1 plasmid. One isolate from a goat abortion in Namibia reacted identically to the reference isolate Priscilla Q177 bearing the QpRS plasmid. Reference isolate S Q217 with plasmid sequences integrated into the genome reacted with none of the plasmid-specific primer pairs.

[New possibilities for the diagnosis of Q fever and for the differentiation of the causative agent]

The current diagnostic procedures for Q fever are discussed, especially isolation and propagation of Coxiella burnetii in BGM cell cultures, detection of antigen by an enzyme immunoassay using a biotinylated monoclonal antibody and the polymerase chain reaction (PCR). The latter is of special importance for differentiation of isolates.

Immunoblot technique for Q fever (technical note)

Partially purified but unfixed C. burnetii cells were submitted to sodium dodecylsulfate polyacrylamide gel electrophoresis, Western blotted and used as antigens for evaluation of antibody responses against the agent in mice, cattle and humans. Increased specificity was achieved by using glutaraldehyde as additional blocking agent. Gels as well as membranes were subjected to laser densitometry and data analysed with an IBM personal computer. This technique offers the possibility to objectively quantify and document the results of immunoblotting.