IEEE Engineering in Medicine and Biology Magazine, 2003
The genetic improvement of livestock species is a very effective and sustainable method for enhan... more The genetic improvement of livestock species is a very effective and sustainable method for enhancing the quality of livestock and their products. Selective breeding can be used to induce genetic changes that are both permanent and cumulative. Gene marker tests are now being used by seed stock and commercial cattle breeders to identify the specific alleles that are present within
Bacterial adherence to intravenous catheters may be mediated, in part, by adherence to coagulatio... more Bacterial adherence to intravenous catheters may be mediated, in part, by adherence to coagulation proteins and platelets. The possibility that catheter infection is associated with gene polymorphisms that cause hypercoagulability or increased platelet stickiness was examined. Among patients with infected catheters, there was no increase in the frequency of polymorphisms that increase coagulability, including factor V Leiden R506G, factor II (prothrombin) G20210A, and methylenetetrahydrofolate reductase C677T, compared with control subjects. The incidence of polymorphisms of the platelet beta(3) integrin among patients with infected catheters was also similar to that among control subjects. The C/D heterozygote of the variable number tandem repeat polymorphism and the C/T heterozygote of the KO polymorphism of glycoprotein Ibalpha were more frequent among patients with infected catheters than they were among control subjects. In a small proportion of patients, a genetic predisposition to platelet stickiness may be associated with infection of intravenous catheters, but in the majority, a recognized genetic tendency to hypercoagulability or platelet stickiness does not underlie infection.
Evaluation of the Luminex NxTAG Respiratory Pathogen Panel was performed on 404 clinical respirat... more Evaluation of the Luminex NxTAG Respiratory Pathogen Panel was performed on 404 clinical respiratory specimens. Clinical sensitivities and specificities of the assay as compared to the reference methods were 80.0-100.0% and 98.9-100.0%, respectively. Correct genotyping information was provided for 95.5% of influenza A virus. The closed tube format of the assay simplified workflow and minimized carryover contamination.
Here we describe four isolations of Erysipelothrix rhusiopathiae associated with polyarthralgia a... more Here we describe four isolations of Erysipelothrix rhusiopathiae associated with polyarthralgia and renal failure, septic arthritis, classic erysipeloid, and peritonitis. Although the biochemical identification was straightforward in each case, recognition presented a challenge to the clinical microbiologist, since in three cases E. rhusiopathiae was not initially considered due to unusual clinical presentations, in two cases the significance might not have been appreciated because growth was in broth only, and in one case the infection was thought to be polymicrobic. Because the Gram stain can be confusing, abbreviated identification schemes that do not include testing for H(2)S production could allow E. rhusiopathiae isolates to be misidentified as Lactobacillus spp. or Enterococcus spp. in atypical infections.
We reviewed the results of microscopic Gram stain examination and routine culture for 2,635 cereb... more We reviewed the results of microscopic Gram stain examination and routine culture for 2,635 cerebrospinal fluid (CSF) samples processed in an adult hospital microbiology laboratory during 55 months. There were 56 instances of bacterial or fungal meningitis (16 associated with central nervous system (CNS) shunt infection), four infections adjacent to the subarachnoid space, four cases of sepsis without meningitis, and
In this chapter we describe two commercially available bead-based molecular assays for detection,... more In this chapter we describe two commercially available bead-based molecular assays for detection, identification and serotyping of Salmonella. The xTAG(®) Gastrointestinal Pathogen Panel (GPP) is a qualitative multiplex test for the simultaneous detection of nucleic acids from Salmonella plus 14 other gastroenteritis-causing bacteria, viruses, and parasites from stool specimens. xTAG GPP uses the Luminex(®) xTAG universal array technology for the identification of specific target sequences combined with the xMAP(®) bead multiplexing platform for detection of the targets that were present in the starting sample. The xMAP Salmonella Serotyping Assay (SSA) is a multiplex nucleic acid-based direct hybridization assay for molecular identification of the serotype of Salmonella isolates. In xMAP SSA, target sequences amplified from cultured Salmonella isolates are captured by hybridization to sequence-specific capture probes which have been coupled to the multiplexed bead sets. Herein we provide detailed protocols for each of these assays and present data which describe their performance characteristics for detection and serotyping Salmonella.
Gastroenteritis persists as a worldwide problem, responsible for approximately 2 million deaths a... more Gastroenteritis persists as a worldwide problem, responsible for approximately 2 million deaths annually. Traditional diagnostic methods used in the clinical microbiology laboratory include a myriad of tests, such as culture, microscopy, and immunodiagnostics, which can be labor intensive and suffer from long turnaround times and, in some cases, poor and Yi-Wei Tang sensitivity. This article reviews recent advances in genomic and proteomic technologies that have been applied to the detection and identification of gastrointestinal pathogens. These methods simplify and speed up the detection of pathogenic microorganisms, and their implementation in the clinical microbiology laboratory has potential to revolutionize the diagnosis of gastroenteritis.
Bacterial adherence to intravenous catheters may be mediated, in part, by adherence to coagulatio... more Bacterial adherence to intravenous catheters may be mediated, in part, by adherence to coagulation proteins and platelets. The possibility that catheter infection is associated with gene polymorphisms that cause hypercoagulability or increased platelet stickiness was examined. Among patients with infected catheters, there was no increase in the frequency of polymorphisms that increase coagulability, including factor V Leiden R506G, factor II (prothrombin) G20210A, and methylenetetrahydrofolate reductase C677T, compared with control subjects. The incidence of polymorphisms of the platelet beta(3) integrin among patients with infected catheters was also similar to that among control subjects. The C/D heterozygote of the variable number tandem repeat polymorphism and the C/T heterozygote of the KO polymorphism of glycoprotein Ibalpha were more frequent among patients with infected catheters than they were among control subjects. In a small proportion of patients, a genetic predisposition to platelet stickiness may be associated with infection of intravenous catheters, but in the majority, a recognized genetic tendency to hypercoagulability or platelet stickiness does not underlie infection.
Difficulties in distinguishing organisms of the "Streptococcus milleri group" (... more Difficulties in distinguishing organisms of the "Streptococcus milleri group" (SMG; Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus), have caused ambiguity in determining their pathogenic potential. We reviewed 118 cases in which SMG isolates had been identified using 16S rDNA sequence. S. constellatus and S. anginosus were isolated far more frequently than was S. intermedius. Nearly all isolates of S. intermedius and most isolates of S. constellatus, but only 19% of those of S. anginosus, were associated with abscess. Our findings suggest that speciation of the SMG may guide diagnostic evaluation, give insight into the possible role of coinfecting organisms, and help assess the need to search for occult abscess.
IEEE Engineering in Medicine and Biology Magazine, 2003
The genetic improvement of livestock species is a very effective and sustainable method for enhan... more The genetic improvement of livestock species is a very effective and sustainable method for enhancing the quality of livestock and their products. Selective breeding can be used to induce genetic changes that are both permanent and cumulative. Gene marker tests are now being used by seed stock and commercial cattle breeders to identify the specific alleles that are present within
Bacterial adherence to intravenous catheters may be mediated, in part, by adherence to coagulatio... more Bacterial adherence to intravenous catheters may be mediated, in part, by adherence to coagulation proteins and platelets. The possibility that catheter infection is associated with gene polymorphisms that cause hypercoagulability or increased platelet stickiness was examined. Among patients with infected catheters, there was no increase in the frequency of polymorphisms that increase coagulability, including factor V Leiden R506G, factor II (prothrombin) G20210A, and methylenetetrahydrofolate reductase C677T, compared with control subjects. The incidence of polymorphisms of the platelet beta(3) integrin among patients with infected catheters was also similar to that among control subjects. The C/D heterozygote of the variable number tandem repeat polymorphism and the C/T heterozygote of the KO polymorphism of glycoprotein Ibalpha were more frequent among patients with infected catheters than they were among control subjects. In a small proportion of patients, a genetic predisposition to platelet stickiness may be associated with infection of intravenous catheters, but in the majority, a recognized genetic tendency to hypercoagulability or platelet stickiness does not underlie infection.
Evaluation of the Luminex NxTAG Respiratory Pathogen Panel was performed on 404 clinical respirat... more Evaluation of the Luminex NxTAG Respiratory Pathogen Panel was performed on 404 clinical respiratory specimens. Clinical sensitivities and specificities of the assay as compared to the reference methods were 80.0-100.0% and 98.9-100.0%, respectively. Correct genotyping information was provided for 95.5% of influenza A virus. The closed tube format of the assay simplified workflow and minimized carryover contamination.
Here we describe four isolations of Erysipelothrix rhusiopathiae associated with polyarthralgia a... more Here we describe four isolations of Erysipelothrix rhusiopathiae associated with polyarthralgia and renal failure, septic arthritis, classic erysipeloid, and peritonitis. Although the biochemical identification was straightforward in each case, recognition presented a challenge to the clinical microbiologist, since in three cases E. rhusiopathiae was not initially considered due to unusual clinical presentations, in two cases the significance might not have been appreciated because growth was in broth only, and in one case the infection was thought to be polymicrobic. Because the Gram stain can be confusing, abbreviated identification schemes that do not include testing for H(2)S production could allow E. rhusiopathiae isolates to be misidentified as Lactobacillus spp. or Enterococcus spp. in atypical infections.
We reviewed the results of microscopic Gram stain examination and routine culture for 2,635 cereb... more We reviewed the results of microscopic Gram stain examination and routine culture for 2,635 cerebrospinal fluid (CSF) samples processed in an adult hospital microbiology laboratory during 55 months. There were 56 instances of bacterial or fungal meningitis (16 associated with central nervous system (CNS) shunt infection), four infections adjacent to the subarachnoid space, four cases of sepsis without meningitis, and
In this chapter we describe two commercially available bead-based molecular assays for detection,... more In this chapter we describe two commercially available bead-based molecular assays for detection, identification and serotyping of Salmonella. The xTAG(®) Gastrointestinal Pathogen Panel (GPP) is a qualitative multiplex test for the simultaneous detection of nucleic acids from Salmonella plus 14 other gastroenteritis-causing bacteria, viruses, and parasites from stool specimens. xTAG GPP uses the Luminex(®) xTAG universal array technology for the identification of specific target sequences combined with the xMAP(®) bead multiplexing platform for detection of the targets that were present in the starting sample. The xMAP Salmonella Serotyping Assay (SSA) is a multiplex nucleic acid-based direct hybridization assay for molecular identification of the serotype of Salmonella isolates. In xMAP SSA, target sequences amplified from cultured Salmonella isolates are captured by hybridization to sequence-specific capture probes which have been coupled to the multiplexed bead sets. Herein we provide detailed protocols for each of these assays and present data which describe their performance characteristics for detection and serotyping Salmonella.
Gastroenteritis persists as a worldwide problem, responsible for approximately 2 million deaths a... more Gastroenteritis persists as a worldwide problem, responsible for approximately 2 million deaths annually. Traditional diagnostic methods used in the clinical microbiology laboratory include a myriad of tests, such as culture, microscopy, and immunodiagnostics, which can be labor intensive and suffer from long turnaround times and, in some cases, poor and Yi-Wei Tang sensitivity. This article reviews recent advances in genomic and proteomic technologies that have been applied to the detection and identification of gastrointestinal pathogens. These methods simplify and speed up the detection of pathogenic microorganisms, and their implementation in the clinical microbiology laboratory has potential to revolutionize the diagnosis of gastroenteritis.
Bacterial adherence to intravenous catheters may be mediated, in part, by adherence to coagulatio... more Bacterial adherence to intravenous catheters may be mediated, in part, by adherence to coagulation proteins and platelets. The possibility that catheter infection is associated with gene polymorphisms that cause hypercoagulability or increased platelet stickiness was examined. Among patients with infected catheters, there was no increase in the frequency of polymorphisms that increase coagulability, including factor V Leiden R506G, factor II (prothrombin) G20210A, and methylenetetrahydrofolate reductase C677T, compared with control subjects. The incidence of polymorphisms of the platelet beta(3) integrin among patients with infected catheters was also similar to that among control subjects. The C/D heterozygote of the variable number tandem repeat polymorphism and the C/T heterozygote of the KO polymorphism of glycoprotein Ibalpha were more frequent among patients with infected catheters than they were among control subjects. In a small proportion of patients, a genetic predisposition to platelet stickiness may be associated with infection of intravenous catheters, but in the majority, a recognized genetic tendency to hypercoagulability or platelet stickiness does not underlie infection.
Difficulties in distinguishing organisms of the "Streptococcus milleri group" (... more Difficulties in distinguishing organisms of the "Streptococcus milleri group" (SMG; Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus), have caused ambiguity in determining their pathogenic potential. We reviewed 118 cases in which SMG isolates had been identified using 16S rDNA sequence. S. constellatus and S. anginosus were isolated far more frequently than was S. intermedius. Nearly all isolates of S. intermedius and most isolates of S. constellatus, but only 19% of those of S. anginosus, were associated with abscess. Our findings suggest that speciation of the SMG may guide diagnostic evaluation, give insight into the possible role of coinfecting organisms, and help assess the need to search for occult abscess.
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