Phenotype microarray analysis of the AdeRS two-component system in Acinetobacter baumannii.

Acinetobacter baumannii is a nosocomial pathogen capable of resistance to multiple antimicrobials. The AdeRS two-component system (TCS) is associated with antimicrobial resistance by controlling the AdeABC efflux pump. To elucidate modulation by AdeRS, we made an A. baumannii mutant lacking the AdeRS TCS and characterized it using phenotype microarray (PM) analysis. After disrupting the adeRS operon, lower expression of AdeABC efflux pump was observed in the mutant strain. PM analysis showed that the AdeRS deletion strain and parental strain presented different tolerances to 91 compounds. Tolerance to 54 of the 91 compounds could be restored by complementing the AdeRS deleted strain with a plasmid carrying the adeRS gene. Compared to the parental strain, the AdeRS deletion strain was more sensitive to various inhibitors that target on-protein synthesis and function of cell membrane permeability. Tolerance to phleomycin of the AdeRS deletion strain reduced greatly and was further confirmed with minimum inhibitory concentration (MIC) determination and spot assay. The efflux pump inhibitor, NMP, could reduce phleomycin MIC four-fold at least for 29 (34.8%) of 81 tigecycline-resistant extensively drug-resistant A. baumannii (TGC-resistant XDRAB) clinical isolates. Our results suggested that the AdeRS TCS of A. baumannii was important for both elimination of antibiotics and tolerance to particular compounds.

Molecular screening of multidrug-resistance tuberculosis by a designated public health laboratory in Taiwan.

This manuscript describes our experience in early identifying MDR-TB cases in high-risk populations by setting up a single-referral molecular diagnosis laboratory in Taiwan. Taiwan Centers for Disease Control designated a single-referral laboratory to provide the GenoType MTBDRplus test for screening high-risk MDR-TB populations nationwide in 2012-2015. A total of 5,838 sputum specimens from 3,308 patients were tested within 3 days turnaround time. Compared with the conventional culture and drug susceptibility testing, the overall performance of the GenoType MTBDRplus test for detecting TB infection showed accuracy of 70.7%, sensitivity of 85.9%, specificity of 65.7%, positive predictive value of 45.5%, and negative predictive value of 93.3%. And the accuracy of detecting rifampin (RIF) resistance, isoniazid (INH) resistance, and MDR-TB (resistant to at least RIF and INH) were 96.5%, 95.2%, and 97.7%, respectively. MDR-TB contacts presented a higher rate of mutated codons 513-519, GenoType MTBDRplus banding pattern: rpoB WT3(-), and rpoB WT4(-) than the treatment failure group. The MDR-TB contact group also had a higher rate of inhA C15T mutation, banding pattern: inhA WT1(-), and inhA MUT1(+) than the recurrent group. Resistance profiles of MDR-TB isolates also varied geographically. The referral molecular diagnosis system contributed to rapid detection and initiation of appropriate therapy.

AdeRS combination codes differentiate the response to efflux pump inhibitors in tigecycline-resistant isolates of extensively drug-resistant Acinetobacter baumannii.

Tigecycline (TGC)-resistant extensively drug-resistant Acinetobacter baumannii (XDRAB) is an increasing threat in regard to nosocomial infections. The resistance-nodulation-cell division (RND) efflux pump has played an important role in TGC resistance. In this study, total 81 TGC-resistant XDRAB isolates were analyzed for their responses to the efflux pump inhibitor 1-(1-naphthylmethyl)-piperazine (NMP). We found that NMP could reduce by 4-fold or greater than 4-fold the minimum inhibitory concentration (MIC) of TGC in 45 isolates (55.6 %). After typing with pulsed-field gel electrophoresis (PFGE), group A appeared to be the major cluster with good synergistic response to NMP. Transcripts of the AdeABC efflux pump gene were consistently more correlated with TGC resistance than transcripts of the AdeFGJ or AdeIJK efflux pump genes in these isolates. Of the 81 isolates, the amino acid sequences of AdeR and AdeS were further classified and combined into 31 different codes. Although the dissemination of TGC-resistant XDRAB isolates was genetically diverse in our hospital, their responses to NMP conversion were still strain-dependent. We found that AdeRS combination codes were better than PFGE typing in separating groups of isolates with different sensitivity to NMP conversion.

Multicentre study evaluating matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of clinically isolated Elizabethkingia species and analysis of antimicrobial susceptibility.

OBJECTIVES: Rapid identification of Elizabethkingia species is essential because these species show variations in antibiotic susceptibility and clinical outcomes. Many recent inaccuracies in Elizabethkingia identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) have been noted. Accordingly, in this study, we evaluated the use of MALDI-TOF MS with an amended database to identify isolates of Elizabethkingia anophelis, E. miricola and E. meningoseptica. We then investigated the antimicrobial susceptibility of Elizabethkingia. METHODS: MALDI-TOF MS spectra were acquired from formic acid extracts overlaid with α-cyano-4-hydroxycinnamic acid matrix on target slides in linear positive ion mode for m/z 2000 to 20 000 Da. Spectra were analysed and SuperSpectra were created with SARAMIS premium software. 16S rRNA gene sequencing was used as the reference standard for species identification. Antibiotic susceptibility was assessed by broth microdilution. RESULTS: A total of 103 E. anophelis, 21 E. miricola and 11 E. meningoseptica isolates were used to calculate the average spectra and exclude common peaks. SuperSpectra were added to the SARAMIS taxonomy database; all validation results were correct, even for isolates not included in SuperSpectra. Confirmation by direct colony formation was also performed. Overall, the positive predictive value of SuperSpectra was 100% for all isolates. E. miricola (77%, 17/22) was more susceptible to levofloxacin than E. anophelis (16%, 17/105). Doxycycline and minocycline were effective against all Elizabethkingia species. CONCLUSIONS: Spectral analysis software identified significant species-specific peaks to create reference masses for efficient and accurate identification of Elizabethkingia species, providing accurate information for clinical treatment of Elizabethkingia infections.

Overexpression of AdeABC efflux pump associated with tigecycline resistance in clinical Acinetobacter nosocomialis isolates.

OBJECTIVES: Tigecycline non-susceptible Acinetobacter nosocomialis (TNAN) has been discovered in clinical isolates. The resistance-nodulation-cell division (RND)-type efflux system plays a major role in tigecycline non-susceptible Acinetobacter baumannii, but the mechanism in A. nosocomialis remains unknown. Our aim was to analyse the contribution of efflux-based tigecycline resistance in clinical A. nosocomialis isolates collected from multiple medical centres in Taiwan. METHODS: A total of 57 A. nosocomialis isolates, including 46 TNAN and 11 tigecycline-susceptible A. nosocomialis (TSAN) isolates, were analysed. Of these, 46 TNAN isolates were clustered to ST410 (43 isolates) and ST68 (three isolates) by multi-locus sequence typing. RESULTS: The relationship between the RND efflux pump and tigecycline resistance was indirectly verified by successfully reducing tigecycline resistance with NMP, an efflux pump inhibitor. The three RND efflux systems (AdeABC, AdeIJK and AdeFGH) were detected in all clinical isolates. The transcript level of adeB gene increased significantly and was correlated with tigecycline resistance. Moreover, the AdeRS two-component system was further classified into four different types of AdeRS patterns considering the amino acid sequence. Further analysis showed that tigecycline resistance was related to the transcript level of adeB gene and the AdeRS pattern. CONCLUSION: This study showed that the dissemination of TNAN isolates in Taiwan is attributable mainly to the spread of ST410. The AdeABC efflux pump appeared to play an important role in the tigecycline resistance of A. nosocomialis.

MNGIE with lack of skeletal muscle involvement and a novel TP splice site mutation.

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal recessive multisystem disorder caused by thymidine phosphorylase (TP) deficiency, resulting in severe gastrointestinal dysmotility and skeletal muscle abnormalities. A patient is reported with a classical MNGIE clinical presentation but without skeletal muscle involvement at morphological, enzymatic, or mitochondrial DNA level, though gastrointestinal myopathy was present. MNGIE was diagnosed by markedly raised plasma thymidine and reduced thymidine phosphorylase activity. Molecular genetic analysis showed a homozygous novel splice site mutation in TP. On immunohistochemical studies there was marked TP expression in the CNS, in contrast to what has been observed in rodents. It is important to examine the most significantly affected tissue and to measure TP activity and plasma thymidine in order to arrive at an accurate diagnosis in this condition.

A prospective randomized comparative trial showing that omeprazole prevents rebleeding in patients with bleeding peptic ulcer after successful endoscopic therapy.

BACKGROUND: A blood clot in a peptic ulcer is unstable in a low pH environment. The use of omeprazole may prevent rebleeding by elevating intragastric pH in patients with bleeding peptic ulcer after hemostasis has been achieved. OBJECTIVES: To assess the influence of using omeprazole and cimetidine on 24-hour intragastric pH and to determine their ability to prevent rebleeding after having achieved initial hemostasis in patients with active bleeding or nonbleeding visible vessels. METHODS: One hundred patients with bleeding peptic ulcers who had obtained initial hemostasis were enrolled in this randomized comparative trial. In the cimetidine group (n = 50), a 300-mg intravenous bolus of cimetidine was given, followed by a 1200-mg continuous infusion daily for 3 days. Thereafter, 400 mg of cimetidine was given orally twice daily for 2 months. In the omeprazole group (n = 50), a 40-mg intravenous bolus of omeprazole was given, followed by 160 mg of continuous infusion daily for 3 days. Thereafter, 20 mg of omeprazole was given orally once daily for 2 months. A pH meter was inserted in each patient's fundus under fluoroscopic guidance after the intravenous bolus of cimetidine or omeprazole had been administered. RESULTS: The stigmata of recent hemorrhage before endoscopic therapy in the omeprazole and cimetidine groups were, respectively, spurting (9 vs 12), oozing (4 vs 9), and nonbleeding visible vessel (37 vs 29) (P > .05). The duration of intragastric pH higher than 6.0 was longer in the omeprazole group (mean [+/- SD], 84.4% +/- 22.9%) than that of the cimetidine group (mean [+/- SD], 53.5% +/- 32.3%) (P < .001). Rebleeding occurred in 2 patients (4%) in the omeprazole group and in 12 patients (24%) in the cimetidine group by day 14 after enrollment (P = .004). There was a tendency for patients in the omeprazole group to require less blood transfusion (median, 0 mL; range, 0-2500 mL) than those in the cimetidine group (median, 0 mL; range, 0-5000 mL) (P = .08). The hospital stay and number of operations and mortality rate were similar between both groups. CONCLUSIONS: The use of omeprazole is more effective than cimetidine in increasing intragastric pH and reducing rebleeding episodes in patients with bleeding peptic ulcers after successful endoscopic therapy. This suggests that omeprazole should be used routinely after successful endoscopic therapy.

Endoscopic haemoclip versus heater probe thermocoagulation plus hypertonic saline-epinephrine injection for peptic ulcer bleeding.

BACKGROUND: Treating patients of bleeding peptic ulcers with heater probe thermocoagulation and haemoclip is considered to be safe and very effective. Yet, there is no report comparing the haemostatic effects of endoscopic haemoclip versus heater probe thermocoagulation plus hypertonic saline-epinephrine injection in these patients. AIM: To compare the clinical outcomes of both therapeutic modalities in patients with peptic ulcer bleeding. METHODS: A total of 93 patients with active bleeding or non-bleeding visible vessels were randomised to receive either endoscopic haemoclip (n = 46) or heater probe thermocoagulation plus hypertonic saline-epinephrine injection (n = 47). Five patients from the haemoclip group were excluded because of the inability to place the haemoclip. RESULTS: Initial haemostasis was achieved in 39 patients (95.1%) of the haemoclip group and 47 patients (100%) of the heater probe group (P > 0.1). Rebleeding occurred in four patients (10.3%) of the haemoclip group and three patients (6.4%) of the heater probe group (P > 0.1). The volume of blood transfused after entry into the study, duration of hospital stay, number of patients requiring urgent surgery and the mortality rates were not statistically different between the two groups. CONCLUSIONS: If the haemoclip can be applied properly, the clinical outcomes of the haemoclip group would be similar to those of the heater probe group in patients with peptic ulcer bleeding. However, if the bleeders are located at the difficult-to-approach sites, heater probe plus hypertonic saline injection is the first choice therapy.

Octreotide for arrest of peptic ulcer hemorrhage--a prospective, randomized controlled trial.

BACKGROUND/AIMS: A prospective, randomized controlled trial was performed over a 10-month period to evaluate the hemostatic effects of octreotide and ranitidine in 84 patients with active peptic ulcer bleeding or nonbleeding visible vessels at the ulcer bases. PATIENTS AND METHODS: Forty-two patients received octreotide 100 mcg bolus intravenously followed by 25 mcg/h intravenously for 1.4 +/- 0.6 days (mean +/- SD). The other 42 patients received ranitidine 100 mg intravenously every 12 h. The two groups were matched for sex, age, location of bleeders, endoscopic findings, shock, and initial hemoglobin. RESULTS: Hemostasis was obtained in 35 (83.3%) of the octreotide group, and 23 (54.8%) of the control group (p<0.01). Volume of blood transfused, numbers of patients receiving aggressive management (endoscopic hemostasis or operation), and hospital stay were significantly less in the octreotide group as compared with those of the controls (p<0.05, p<0.05 and p<0.001, respectively). No obvious side effect was found in the octreotide group. CONCLUSION: We suggest that octreotide is a safe and effective drug in arresting peptic ulcer hemorrhage. It may be used as the first-line therapy for a patient with massive peptic ulcer hemorrhage before he is transferred to a medical center.

Can optimal acid suppression prevent rebleeding in peptic ulcer patients with a non-bleeding visible vessel: a preliminary report of a randomized comparative study.

BACKGROUND/AIMS: The hypothesis that profound acid suppression might prevent clot lysis and thus benefit patients with a non-bleeding visible vessel has not been confirmed. Omeprazole can suppress gastric acid remarkably and may be beneficial for patients with peptic ulcer bleeding. METHODOLOGY: Fifty-two patients with a non-bleeding visible vessel at the ulcer base were enrolled and randomized into four groups (N = 13 in each group). In the cimetidine group, the patients received cimetidine 300 mg i.v. bolus followed by 300 mg i.v. every 6 hr during hospitalization. In the heater probe thermocoagulation + cimetidine group, the patients received heater probe thermocoagulation and cimetidine 300 mg i.v. bolus followed by 300 mg i.v. every 6 h during hospitalization. In the omeprazole q.d. group, the patients received omeprazole 40 mg i.v. bolus followed by 40 mg i.v. daily for two days. In the omeprazole q 12 h group, the patients received omeprazole 40 mg i.v. bolus followed by 40 mg i.v. every 12 h for two days. A 24 hr intragastric pH was recorded for every case. RESULTS: The mean 24 hr intragastric pH were higher in the omeprazole q.d. (mean 5.8) and the omeprazole q 12 h groups (mean 6.4) than in the cimetidine (mean 4.3) and the heater probe thermocoagulation + cimetidine groups (mean 4.9) (p < 0.05). Rebleeding occurred in 5, 2, 2 and 2 patients in the cimetidine, heater probe thermocoagulation + cimetidine, omeprazole q.d., and omeprazole q 12 h groups, respectively (p > 0.05). Volume of blood transfusion and number of days in hospital were not statistically different among the four groups. CONCLUSIONS: Omeprazole can remarkably suppress gastric acid when it is compared to that of the H2 receptor blocker. Patients with a non-bleeding visible vessel using omeprazole do not exhibit a decrease in the rebleeding rate as compared with those patients using cimetidine.

The influence of intravenous omeprazole on intragastric pH and outcomes in patients with peptic ulcer bleeding after successful endoscopic therapy--a prospective randomized comparative trial.

BACKGROUND/AIMS: The role of omeprazole in preventing rebleeding in patients with peptic ulcer bleeding after successful endoscopic therapy has been controversial. In this study, we used 3 different formulas of intravenous omeprazole in the above patients. We wished to compare the intragastric pH and outcomes among them. METHODOLOGY: Between July 1996 and May 1997, after having obtained initial hemostasis with endoscopic therapy, a total of 20 patients with peptic ulcer bleeding (spurting/oozing/non-bleeding visible vessel: 6/4/10) received intravenous bolus of omeprazole 20 mg every 3 hours; 20 patients (3/5/12) received intravenous bolus of omeprazole 40 mg every 6 hours; and, 20 patients (5/4/11) received intravenous bolus of omeprazole 80 mg every 12 hours for 3 days. One intragastric pH meter (Gastrograph Mark III, Medical Instruments Corp. Switzerland) was used to record 24-hour intragastic pH. RESULTS: The intragastric pH in the patients receiving omeprazole 20 mg every 3 hours was 6.1, 6.0-6.2 (mean: 95% CI); in patients receiving omeprazole 40 mg every 6 hours it was 6.4, 6.2-6.5; and, in patients receiving omeprazole 80 mg every 12 hours it was 5.8, 5.7-5.9. The duration of intragastric pH > 6.0 in omeprazole 20 mg every 3 hours was 70.9%, 57.3%-84.4% (mean: 95% CI); in omeprazole 40 mg every 6 hours it was 83.1%, 73.1%-93.1%; and, in omeprazole 80 mg every 12 hours it was 66%, 51.5%-80.4%. Patients with peptic ulcers receiving omeprazole 40 mg intravenous bolus every 6 hours had the highest intragastric pH as compared with the other 2 groups (p < 0.0001). There were no significant differences concerning rebleeding rates, volume of blood transfusion, hospital stay, numbers of operation and mortality among the 3 groups. CONCLUSIONS: After initial hemostasis had been obtained, patients with peptic ulcer bleeding receiving 40 mg intravenous bolus every 6 hours had the highest intragastric pH. However, they had similar outcomes with the other 2 groups.

A 3-day anti-Helicobacter pylori therapy is a good alternative for bleeding peptic ulcer patients with Helicobacter pylori infection.

BACKGROUND/AIMS: One-week triple therapy has been recommended as a standard regimen for eradicating Helicobacter pylori infection. The emergence of antibiotic-resistant strains, adverse drug effects, poor compliance and high cost of therapy add problems to the management of these patients. In this study, we assessed whether a 3-day triple therapy could be effective in eradicating Helicobacter pylori infection in bleeding peptic ulcer patients. METHODOLOGY: Peptic ulcer patients with Helicobacter pylori infection were enrolled in this study. Patients enrolled at the outpatient department (group A) received a 7-day oral regimen: bismuth subcitrate colloid 300 mg + amoxicillin 500 mg + metronidazole 250 mg four times per day. Patients who were admitted to the wards due to peptic ulcer bleeding (group B) received a 3-day regimen including omeprazole 40 mg intravenously every 6 hours, amoxicillin 500 mg + metronidazole 250 mg orally four times daily after hemostasis had been achieved. Patients of both groups received omeprazole 20 mg once per day or cimetidine 400 mg twice daily per os for at least-one month after anti-Helicobacter pylori therapy. We followed every patient endoscopically two months after anti-Helicobacter pylori therapy. RESULTS: From June 1997 to April 1999, a total of 57 patients (30 in group A and 27 in group B) with gastric or duodenal ulcer and Helicobacter pylori infection completed anti-Helicobacter pylori therapy. Two months after anti-Helicobacter pylori therapy, peptic ulcer was found to be healed with a scar in 26 (86.7%) of group A and 23 (85.2%) of group B (P > 0.1). The eradication rates of Helicobacter pylori in the two groups were not significantly different in an intention-to-treat analysis [group A: 78.8% (26/33), 95% CI: 64.9-92.7%; group B: 80% (24/30), 95% CI: 65.7-94.3%, P > 0.1] and in a per protocol analysis [group A: 86.7% (26/30), 95% CI: 74.5-98.9%, group B: 88.9% (24/27), 95% CI: 77.1-100.7%, P > 0.1]. Fewer side effects occurred in group B (3/30) than those in group A (7/33) (P > 0.1). CONCLUSIONS: In patients with peptic ulcer bleeding a 3-day anti-Helicobacter pylori therapy is a good alternative for eradicating Helicobacter pylori infection.

Is submucosal epinephrine injection necessary before polypectomy? A prospective, comparative study.

BACKGROUND/AIMS: Polyps of the gastrointestinal tract are usually removed due to their link to bleeding, obstruction and malignancy. However, complications may occur following polypectomy. The aim of this study was to assess whether submucosal epinephrine injection before polypectomy could reduce the incidence of bleeding and perforation. METHODOLOGY: Between June 1997 and November 1999, patients with sessile polyps of the gastrointestinal tract found in our endoscopic unit were randomized to receive submucosal epinephrine injection (epinephrine group) or no injection (control group) before polypectomy. In the epinephrine group, epinephrine (1:10,000) was injected surrounding the stalk of the polyp until the mucosa was blanched and bulged. The patients were observed for complications in the following month. RESULTS: A total of 120 patients with 151 sessile polyps were enrolled in this study. In the epinephrine group, 75 polyps (n = 68) were randomized to receive epinephrine injection before polypectomy. In the control group, 76 polyps (n = 61) underwent polypectomy without epinephrine injection. In both groups, there was no significant difference in clinical features including the sizes of the polyps and their stalks, the location of polyps and the pathological diagnosis. There were a total of nine episodes of post-polypectomy hemorrhage, two in the epinephrine group and seven in the control group (2/75 vs. 7/76) (P = 0.07). One case in the epinephrine group experienced delayed bleeding (4 days later). Immediate hemorrhage occurred less in the epinephrine group than that in the control group (1/75 vs. 7/76, P = 0.03). There was one case of perforation in each group. CONCLUSIONS: Epinephrine injection prior to polypectomy is effective in preventing immediate bleeding.

Effect of non-steroidal anti-inflammatory drugs on gastric and duodenal prostaglandin concentrations in patients with Helicobacter pylori infection.

BACKGROUND/AIMS: Both Helicobacter pylori and non-steroidal anti-inflammatory drugs are reported to affect gastroduodenal prostaglandin synthesis. However, their influence on gastric mucosal prostaglandins remains unclear. The aim of this study was to investigate the influence of nonsteroidal anti-inflammatory drugs on mucosal prostaglandin synthesis in patients with Helicobacter pylori infection. METHODOLOGY: We enrolled 87 Helicobacter pylori-infected patients in this study (gastric ulcer: 33, duodenal ulcer: 41, and non-ulcer dyspepsia: 13). Of them, 27 patients received non-steroidal anti-inflammatory drugs. Endoscopy was performed and biospy specimens from gastric body, antrum and duodenal bulb were assessed for Helicobacter pylori and prostaglandin concentration. RESULTS: A significantly lower mucosal prostaglandin E2 level at gastric body (142.2 +/- 28.1 ng/mg vs. 222.0 +/- 12.4 ng/mg, mean +/- SEM) and antrum (131.3 +/- 26.4 ng/mg vs. 226.0 +/- 19.0 ng/mg) was noted in Helicobacter pylori-infected gastric ulcer patients with non-steroidal anti-inflammatory drugs ingestion than in that of patients without non-steroidal anti-inflammatory drugs ingestion (p < 0.05). Using a multivariate analysis, we found that non-steroidal anti-inflammatory drug was an independent variable affecting gastric and duodenal mucosal prostaglandin E2 synthesis in patients with Helicobacter pylori-infected gastric ulcer. CONCLUSIONS: Non-steroidal anti-inflammatory drugs decrease gastroduodenal mucosal prostaglandin E2 synthesis in gastric ulcer patients with Helicobacter pylori infection.

Varicella arthritis diagnosed by polymerase chain reaction.

We report a 2-year-old girl who developed acute arthritis of the left knee 4 days after the onset of a typical varicella infection. She was first thought to have pyogenic arthritis caused by Staphylococcus aureus. Accordingly, oxacillin was administered upon hospitalization. On the third day after hospitalization, bacterial cultures of the synovial fluid and blood showed no growth and oxacillin was discontinued. Although a viral culture of the synovial fluid for varicella-zoster virus (VZV) was negative, varicella DNA was identified by means of polymerase chain reaction (PCR) with VZV-specific primers. The patient recovered spontaneously. To differentiate this condition from septic arthritis is important. PCR is a sensitive technique that can demonstrate the presence of VZV DNA in synovial fluid, even if viral cultures are negative.

Pseudomelanosis duodeni: report of eight cases.

Pseudomelanosis duodeni is an uncommon endoscopic sign characterized by diffuse small black spots on the first and second portions of the duodenum. It occurs predominantly in female and elderly patients and is linked to chronic illnesses and related medications. Between 1988 and 1994, the authors saw eight patients with pseudomelanosis duodeni. To evaluate the nature of the pigments, special staining was performed in seven cases. Iron stain was strongly positive in three cases. Electron microscopy was performed in two cases. This revealed amorphous bodies within macrophage lysosomes in one case and angular crystals in another case. These tests suggest that in pseudomelanosis duodeni iron metabolism may be impaired and iron is pooled within macrophages.

Characterization of the first clinical isolate of vancomycin-resistant Enterococcus faecalis, AH803, in Taiwan.

We previously isolated a vancomycin-resistant strain of Enterococcus faecalis, designated AH803, from the sputum of a patient with pneumonia and bacteremia in Taiwan. AH803 was resistant to vancomycin (minimal inhibitory concentration, MIC = 512 micrograms/mL) but susceptible to teicoplanin (MIC = 8 micrograms/mL), and harbored the vanA gene but not the vanB gene. In this study, we further characterized E. faecalis AH803 and the plasmid it was found to contain. DNA from AH803 was analyzed for the presence of vanA and vanB resistance genes by polymerase chain reaction. The vancomycin resistant phenotype was transferable from AH803 to E. faecalis JH2-2, at a frequency of 4.8 x 10(-2). AH803 was also resistant to gentamicin and chloramphenicol, and these antibiotic resistance phenotypes cotransferred with vancomycin resistance. The genes responsible for resistance to all three antibiotics were located on a 42-kb conjugative plasmid (pBL101). This plasmid had the same restriction enzyme digestion patterns as Tn1546, found in pIP816 of E. faecalis BM4147. Epidemiologic studies of glycopeptide resistance should perhaps combine phenotypic and genotypic methods, rather than using phenotypic methods alone.

Characterization of a highly glycopeptide-resistant Enterococcus gallinarum isolate.

BACKGROUND AND PURPOSE: Adequate treatment of emergency infection involving antibiotic-resistant bacteria such as vancomycin-resistant Enterococcus requires a convergence of clinical and bacteriologic techniques. An isolate of Enterococcus gallinarum, designated as TSGH63, is known to be uncommonly vancomycin-resistant. This study investigated the genetic determinant for this unique characteristic. METHODS: After completing the conventional identification and sensitivity tests, the genomic content of E. gallinarum TSGH63 was extracted and analyzed by pulse-field electrophoresis. A set of specific primers for vanA, vanB, vanC1, and vanC2/C3 genes was then applied in a multiplex polymerase chain reaction (PCR) to differentiate its genetic content. To locate the determinant for high vancomycin resistance, the electrophoresis profile was further analyzed by Southern blot using the digoxigenin (DIG)-labeled vanA gene probe. Finally, interspecies transfer of the vancomycin-resistance determinant of E. gallinarum TSGH63 was tested by a conjugation experiment in vitro. RESULTS: A 50-kb plasmid was identified in the analysis of the genomic extract of E. gallinarum TSGH63 by pulse field electrophoresis. Using multiplex PCR, we demonstrated that E. gallinarum TSGH63 harbors a vanA gene in addition to a vanC1 gene. The DIG-labeled vanA gene-specific probe bound to the plasmid exclusively on the Southern blot. The plasmid-carried vanA gene, but not the vanC1 gene, was found to be transferable from TSGH63 to E. faecalis JH2-2 by conjugation in vitro. CONCLUSIONS: This is the first report of isolation of E. gallinarum with a high level of resistance to glycopeptides in Taiwan. The demonstrated interspecies transfer of the vancomycin-resistance gene highlights the importance of stringent control of the use of vancomycin.