1
|
Brothwell JA, Fortney KR, Williams JS, Batteiger TA, Duplantier R, Grounds D, Jannasch AS, Katz BP, Spinola SM. Formate production is dispensable for Haemophilus ducreyi virulence in human volunteers. Infect Immun 2023; 91:e0017623. [PMID: 37594273 PMCID: PMC10501210 DOI: 10.1128/iai.00176-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 06/29/2023] [Indexed: 08/19/2023] Open
Abstract
Haemophilus ducreyi is a causative agent of cutaneous ulcers in children who live in the tropics and of the genital ulcer disease chancroid in sexually active persons. In the anaerobic environment of abscesses and ulcers, anaerobic respiration and mixed acid fermentation (MAF) can be used to provide cellular energy. In Escherichia coli, MAF produces formate, acetate, lactate, succinate, and ethanol; however, MAF has not been studied in H. ducreyi. In human challenge experiments with H. ducreyi 35000HP, transcripts of the formate transporter FocA and pyruvate formate lyase (PflB) were upregulated in pustules compared to the inocula. We made single and double mutants of focA and pflB in 35000HP. Growth of 35000HPΔfocA was similar to 35000HP, but 35000HPΔpflB and 35000HPΔfocA-pflB had growth defects during both aerobic and anaerobic growth. Mutants lacking pflB did not secrete formate into the media. However, formate was secreted into the media by 35000HPΔfocA, indicating that H. ducreyi has alternative formate transporters. The pH of the media during anaerobic growth decreased for 35000HP and 35000HPΔfocA, but not for 35000HPΔpflB or 35000HPΔfocA-pflB, indicating that pflB is the main contributor to media acidification during anaerobic growth. We tested whether formate production and transport were required for virulence in seven human volunteers in a mutant versus parent trial between 35000HPΔfocA-pflB and 35000HP. The pustule formation rate was similar for 35000HP (42.9%)- and 35000HPΔfocA-pflB (62%)-inoculated sites. Although formate production occurs during in vitro growth and focA-pflB transcripts are upregulated during human infection, focA and pflB are not required for virulence in humans.
Collapse
Affiliation(s)
- Julie A. Brothwell
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Kate R. Fortney
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Jalan S. Williams
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Teresa A. Batteiger
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Rory Duplantier
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Danielle Grounds
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Amber S. Jannasch
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, USA
| | - Barry P. Katz
- Department of Biostatistics and Health Data Sciences, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Stanley M. Spinola
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| |
Collapse
|
2
|
Heise C, Dandekar S, Kumar P, Duplantier R, Donovan RM, Halsted CH. Human immunodeficiency virus infection of enterocytes and mononuclear cells in human jejunal mucosa. Gastroenterology 1991; 100:1521-7. [PMID: 2019358 DOI: 10.1016/0016-5085(91)90648-5] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Intestinal malabsorption is a recognized cause of malnutrition in patients infected with human immunodeficiency virus. However, the relationships among human immunodeficiency virus infection, morphological changes in the intestine, and development of intestinal malabsorption are not well established. Nine patients infected with human immunodeficiency virus underwent tests of intestinal absorption and jejunal biopsies for morphometric measurements, enzyme assays, and virus detection by in situ hybridization. Steatorrhea and low lactase activities were found in more than 85% of the patients. All biopsy specimens were abnormal with reversal of the ratio of villus length to crypt depth in seven and enlarged enterocyte nuclear size in nine. Human immunodeficiency virus was detected in five jejunal biopsy specimens, within villus enterocytes of one patient who had the most severe malabsorption of the group and in four other biopsy specimens in mononuclear infiltrating cells of the lamina propria. These results suggest that human immunodeficiency virus infection of the small intestinal mucosa is an early event that is associated with altered enterocyte differentiation and function.
Collapse
Affiliation(s)
- C Heise
- Department of Internal Medicine, University of California, Davis
| | | | | | | | | | | |
Collapse
|
3
|
Abstract
The etiology of malnutrition and the metabolic effect of aggressive nutritional support by enteral feeding were evaluated in patients with moderately severe alcoholic hepatitis. Among 21 patients presenting with jaundice, ascites, coagulopathy and low grade encephalopathy, the mean digestibilities (intake - fecal excretion/intake x 100) of total energy and fat were subnormal at 74.6 +/- 2.9 and 64.5 +/- 4.4%, respectively, and nitrogen balance was negative in half the patients with a mean value of +0.74 gm per day +/- 1.2. Based on initial ad libitum intake of hospital diet, patients were grouped as six patients with adequate caloric intake who underwent a repeated 3-day balance study to assess the effect of hospitalization (Group I) and eight anorectic patients who underwent a repeat balance study during constant nasoduodenal infusion of the liquid formula Isocal-HCN in an amount sufficient to provide 35 kcal per kg ideal body weight (Group II). During the initial phase of hospital tray diet, the mean digestibilities of energy, fat, protein and carbohydrate, and the mean nitrogen balance were similar in each group. The digestibilities of each diet constituent and nitrogen balance were similar in both phases of hospital tray diet in patients in Group I. On the other hand, the infusion of Isocal-HCN to patients in Group II resulted in significant increases over their baseline values in intakes of energy and protein and in digestibilities of energy, fat and protein, and in a 5-fold increase in nitrogen balance. Provision of essential nutrients by enteric infusion had no effect on fluid balance or degree of encephalopathy.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- S Soberon
- Division of Clinical Nutrition, University of California-Davis 95616
| | | | | | | | | |
Collapse
|