Protective effects of Lactuca sativa ethanolic extract on carbon tetrachloride induced oxidative damage in rats

Objective

To study the protective effects of the ethanolic extract of lettuce (Lactuca sativa L. var. longifolia) leaves against the toxicity caused by carbon tetrachloride (CCl₄) in reproductive system of rats.

Methods

Lettuce leaves were dried and extracted with ethanol (plant: solvent, 1:10, w/v). The extract was filtered and evaporated to yield dried lettuce extract. Animals were divided into seven groups and treated with CCl₄ and different concentrations of lettuce extract. At the end of the experimental period, the animals were sacrificed and blood was collected and centrifuged for serum separation. Body weights, testis size, histopathology of testis and liver, catalase (CAT) activity, superoxide dismutase (SOD) activity, peroxidase (POD) activity, reduced glutathione (GSH), glutathione peroxidase activity (GSH-Px), thiobarbituric acid reactive substances (TBARS), nitrite level, and serum hormones were determined.

Results

Oxidative stress induced by CCl₄ (2 mL/kg body weight) in rat decreases the increase in body weight and relative testis weight. It also markedly increases the level of TBARS and nitrites along with corresponding decrease in reduced glutathione and various antioxidant enzymes in testis (i.e., CAT, POD, SOD and GSH-Px). Serum level of testosterone, luteinizing hormone and follicle stimulating hormone was decreased while estradiol and prolactin were increased during CCl₄ treatment. Histopathology of CCl₄-treated rats indicated the partial degeneration of germ and leydig cells along with deformities in spermatogenesis. Supplementation of lettuce extract (100, 150, 200 mg/kg body weight orally) once a week for 10 weeks results in decrease of TBARS and nitrite, while increase in antioxidant enzymes; CAT, POD, SOD, GSH-Px and GSH contents. Serum level of testosterone, luteinizing hormone, follicle stimulating hormone, estradiol, prolactin, histology, body weight and relative testis weight was also concomitantly restored to near normal level by lettuce extract supplementation to CCl₄-intoxicated rat.

Conclusions

The results clearly demonstrate that lettuce extract treatment augments the antioxidants defense mechanism against CCl₄-induced toxicity and provides evidence that it may have a therapeutic role in free radical mediated diseases.     

Evaluation of hepatoprotective effect of methanolic extract of Clitoria ternatea (Linn.) flower against acetaminophen-induced liver damage

Objective

To evaluate the hepatoprotective and antioxidant activity of Clitoria ternatea (C. ternatea) flower extract against acetaminophen-induced liver toxicity.

Methods

The antioxidant property of C. ternatea flower extract was investigated by employing established in vitro antioxidant assay. The C. ternatea flower extract was studied in this work for its hepatoprotective effect against acetaminophen-induced liver toxicity in mice. Activity was measured by monitoring the levels of aspartate aminotransferase, alanine aminotransferase, billirubin and glutathione with histopathological analysis.

Results

The amount of total phenolics and flavonoids were estimated to be 105.40±2.47 mg/g gallic acid equivalent and 72.21±0.05 mg/g catechin equivalent respectively. The antioxidant activity of C. ternatea flower extract was 68.9% at a concentration of 1 mg/mL and was also concentration dependant, with an IC₅₀ value of 327.00 µg/mL. The results of acetaminophen-induced liver toxicity experiment showed that mice treated with the extract (200 mg/kg) showed a significant decrease in alanine aminotransferase, aspartate aminotransferase, and bilirubin levels, which were all elevated in the paracetamol group (P<0.05). Meanwhile, the level of glutathione was found to be restored in extract treated animals compared to the groups treated with acetaminophen alone (P<0.05). Therapy of extract also showed its protective effect on histopathological alterations and supported the biochemical finding.

Conclusion

The present work confirmed the hepatoprotective effect of C. ternatea flower against model hepatotoxicant acetaminophen.     

In-vivo anti-inflammatory and anti-pyretic activities of Manilkara zapota leaves in albino Wistar rats

Objective

To screen ethanolic extracts of Manilkara zapota leaves (Family: Sapotaceae) and its different solvent soluble fractions for possible anti-inflammatory, anti-pyretic activities in experimental albino Wistar rats.

Methods

Anti-inflammatory activity was evaluated by carrageenan induced paw edema method; anti-pyretic potential was determined by yeast-induced pyrexia method in albino Wistar rats.

Results

In evaluation of anti-inflammatory activity the crude ethanolic (300 mg/kg) and ethyl acetate extract (300 mg/kg) showed significant inhibition of paw edema by 91.98% and 92.41% (P<0.001) respectively at 4th h compared to standard diclofenac (86.08% inhibition). In anti-pyretic study by yeast-induced pyrexia in albino Wistar rats, the ethanol extract (300 mg/kg) reduced temperature from 37.90 °C to 37.41 °C (P<0.01) and 37.07 °C (P<0.001) in 3rd and 4th h respectively. Similarly, both petroleum ether and ethyl acetate fractions exhibited significant anti-pyretic property (P<0.001). The maximum body temperature lowering effect (36.86 °C) was noticed by petroleum ether fraction.

Conclusions

The findings of the studies demonstrated both anti-inflammatory and anti-pyretic activities of the leaves of Manilkara zapota which could be the therapeutic option against inflammatory disease and pyrexia.     

Laboratory and field efficacy of Pedalium murex and predatory copepod,Mesocyclops longisetus on rural malaria vector,Anopheles culicifacies

Objective

To test the potentiality of the leaf extract of Pedalium murex (P. murex) and predatory copepod Mesocyclops longisetus (M. longisetus) in individual and combination in controlling the rural malarial vector, Anopheles culicifacies (An. culicifacies) in laboratory and field studies.

Methods

P. murex leaves were collected from in and around Erode, Tamilnadu, India. The active compounds were extracted with 300 mL of methanol for 8 h in a Soxhlet apparatus. Laboratory studies on larvicidal and pupicidal effects of methanolic extract of P. murex tested against the rural malarial vector, An. culicifacies were significant.

Results

Evaluated lethal concentrations (LC₅₀) of P. murex extract were 2.68, 3.60, 4.50, 6.44 and 7.60 mg/L for I, II, III, IV and pupae of An. culicifacies, respectively. Predatory copepod, M. longisetus was examined for their predatory efficacy against the malarial vector, An. culicifacies. M. longisetus showed effective predation on the early instar (47% and 36% on I and II instar) when compared with the later ones (3% and 1% on III and IV instar). Predatory efficacy of M. longisetus was increased (70% and 45% on I and II instar) when the application was along with the P. murex extract.

Conclusions

Predator survival test showed that the methanolic extract of P. murex is non-toxic to the predatory copepod, M. longisetus. Experiments were also conducted to evaluate the efficacy of methanolic extract of P. murex and M. longisetus in the direct breeding sites (paddy fields) of An. culicifacies. Reduction in larval density was very high and sustained for a long time in combined treatment of P. murex and M. longisetus.     

Noninvasive transcutaneous sampling of glucose by electroporation

Background

In people with diabetes, blood glucose levels should be monitored regularly to prevent serious complications associated with diabetes. This involves the invasive method of withdrawing blood, which causes inconvenience to patients. The objective of this study was to investigate the efficiency of the noninvasive electroporation and transcutaneous sampling (ETS) technique for predicting blood glucose levels.

Methods

In vitro studies were carried out in Franz diffusion cells using porcine epidermis to assess the feasibility of transcutaneous sampling of glucose. In vivo, the ETS technique was assessed in the diabetes-induced Sprague—Dawley rat model. Glucose was sampled following the application of 30 electrical pulses of 1 ms duration at 120 V/cm², 1 Hz. Clarke error grid analysis was carried out for the venous blood glucose levels that were determined by the ETS with reference to those measured by a glucose meter.

Results

The amount of glucose sampled by the ETS method both in vitro and in vivo was proportional to the dermal glucose concentration. All data points from in vivo studies were in A and B zones of Clarke error grid analysis, and the mean absolute relative error was 12.8%.

Conclusion

Results of the present study demonstrate that ETS technique could be developed as a noninvasive method of predicting venous blood glucose levels in people with diabetes.     

Rifaximin Plus Levofloxacin-Based Rescue Regimen for the Eradication of Helicobacter pylori

Background/Aims

This study assessed the efficacy of a rifaximin plus levofloxacin-based rescue regimen in patients that had failed both triple and quadruple standard regimens for the eradication of Helicobacter pylori.

Methods

We treated patients for H. pylori between August 2009 and April 2011. The triple regimen consisted of combined treatment with amoxicillin, clarithromycin, and pantoprazole for 1 week. For failed cases, a quadruple regimen of tetracycline, metronidazole, bismuth dicitrate, and lansoprazole for 1 week was administered. The rescue regimen for persistently refractory cases was rifaximin 200 mg t.i.d., levofloxacin 500 mg q.d., and lansoprazole 15 mg b.i.d. for 1 week.

Results

In total, 482 patients were enrolled in this study. The eradication rates associated with the first and second regimens were 58% and 60%, respectively. Forty-seven out of 58 patients who failed with the second-line regimen received rifaximin plus levofloxacin-based third-line therapy. The eradication rate for the third regimen was 65%. The cumulative eradication rates were 58%, 85%, and 96% for each regimen, respectively.

Conclusions

A rifaximin plus levofloxacin-based regimen could be an alternative rescue therapy in patients with resistance to both triple and quadruple regimens for the eradication of H. pylori.     

Selective Toxicity of Persian Gulf Sea Cucumber (Holothuria parva) and Sponge (Haliclona oculata) Methanolic Extracts on Liver Mitochondria Isolated from an Animal Model of Hepatocellular Carcinoma

Background:

Natural products isolated from marine environments are well known for their pharmacodynamic potential in diverse disease treatments, such as for cancer or inflammatory conditions. Sea cucumbers are marine animals of the phylum Echinoderm and the class Holothuroidea, with leathery skin and gelatinous bodies. Sponges are important components of Persian Gulf animal communities, and the marine sponges of the genus Haliclona have been known to display broad-spectrum biological activity. Many studies have shown that sea cucumbers and sponges contain antioxidants and anti-cancer compounds.

Objectives:

This study was designed to determine the selective toxicity of Persian Gulf sea cucumber (Holothuria parva) and sponge (Haliclona oculata) methanolic extracts on liver mitochondria isolated from an animal model of hepatocellular carcinoma, as part of a national project that hopes to identify novel potential anticancer candidates among Iranian Persian Gulf flora and fauna.

Materials and Methods:

To induce hepatocarcinogenesis, rats were given diethylnitrosamine (DEN) injections (200 mg/kg i.p. by a single dose), and then the cancer was promoted with 2-acetylaminofluorene (2-AAF) (0.02 w/w) for two weeks. Histopathological evaluations were performed, and levels of liver injury markers and a specific liver cancer marker (alpha-fetoprotein), were determined for confirmation of hepatocellular carcinoma induction. Finally, mitochondria were isolated from cancerous and non-cancerous hepatocytes.

Results:

Our results showed that H. parva methanolic extracts (250, 500, and 1000 µg/mL) and H. oculata methanolic extracts (200, 400, and 800 µg/mL) increased reactive oxygen species (ROS) formation, mitochondrial membrane potential (MMP), mitochondrial swelling, and cytochrome c release in the mitochondria obtained from cancerous hepatocytes, but not in mitochondria obtained from non-cancerous liver hepatocytes. These extracts also induced caspase-3 activation, which is known as a final mediator of apoptosis, in the hepatocytes obtained only from cancerous, not non-cancerous, rat livers.

Conclusions:

Our results suggest that H. parva and H. oculata may be promising therapeutic candidates for the treatment of HCC, following further confirmatory in vivo experiments and clinical trials.     

Effects of hydro-ethanol extract of Citrullus colocynthis on blood glucose levels and pathology of organs in alloxan-induced diabetic rats

Objective

To evaluated the differential effects of ethanol extraction of Citrullus colocynthis (C. colocynthis) on the blood glucose concentration and pathology of pancreas, liver, lungs, kidney and gastrointestinal tract in the alloxan induced diabetes in rats.

Methods

Diabetes mellitus was induced in 20 adult female Albino rats, using intraperitoneal injection of 120 mg/kg alloxan. The diabetic rats were randomly assigned into two equal groups. The first group was treated with the extract of C. colocynthis seed (300 mg/kg) and the rats of the second group, as an untreated diabetic group, received ordinary diet. Ten non diabetic rats remained as a normal control group.

Results

The results of this study indicate that C. colocynthis was able to reduce blood glucose significantly compared with the control diabetic group (P<0.05). Histopathologically, alloxan resulted in severe necrotic changes in the pancreatic islets, especially in the central area of the islets. Tissue sections of the pancreas in the treated rats demonstrated enhanced regeneration of B cells and increased size of pancreatic islets. Liver of the treated diabetic rats revealed significant improvement of the hepatic tissue compared to those of the untreated diabetic rats.

Conclusions

The present study indicated a significant anti-hyperglycemic effect of C. colocynthis seed and supported its traditional usage in treatment of diabetes mellitus.     

Pasteurella species peritoneal dialysis-associated peritonitis: Household pets as a risk factor

BACKGROUND:

Pasteurella species are Gram-negative coccobacilli that are a part of the normal oropharyngeal flora of numerous domestic animals. They have been recognized as a rare but significant cause of peritonitis in patients undergoing peritoneal dialysis (PD). A consensus about management strategies for PD-associated peritonitis caused by Pasteurella species currently does not exist.

METHODS:

The microbiological database serving the Manitoba Renal Program was searched from 1997 to 2013 for cases of Pasteurella species PD-associated peritonitis, and charts were reviewed. PubMed was searched for case reports and data were abstracted.

RESULTS:

Seven new local cases and 30 previously reported cases were analyzed. This infection is clinically similar to other forms of PD peritonitis, with household pet exposure appearing to be the strongest risk factor. Cats are the most commonly implicated pet. Direct contact between the pet and the equipment was commonly reported (25 of 37 patients) but was not necessary for infection to develop. The mean duration of treatment was 15 days. Complication rates were low, with only 11% of patients requiring PD catheter removal. There was no mortality reported.

CONCLUSION:

Pasteurella species are a rare cause of PD-associated peritonitis that can be successfully treated with a two-week course of intraperitoneal antibiotics with a high likelihood of catheter salvage.     

Effect of Helicobacter pylori Eradication on the Development of Reflux Esophagitis and Gastroesophageal Reflux Symptoms: A Nationwide Multi-Center Prospective Study

Background/Aims

A two-year, prospective, nationwide multicenter study was undertaken to evaluate the effect of Helicobacter pylori eradication on the development of reflux esophagitis (RE) and gastroesophageal reflux disease (GERD) symptoms in the Korean population.

Methods

In total, 1,489 subjects without RE were enrolled at the outpatient clinics of 12 tertiary hospitals nationwide, and 452 subjects underwent follow-up (F/U) for 2 years to evaluate the development of RE and GERD symptoms.

Results

RE was found in 33 subjects (7.3% of 452 subjects) and 14 subjects (7.3% of 192 subjects) during the first and second year of F/U, respectively. H. pylori status was not associated with the development of RE. RE was found in six (9.0%) of 67 H. pylori-negative patients, in 26 (11.2%) of 233 eradicated subjects and in eight (7.0%) of 114 noneradicated subjects (p=0.532). Multivariate analysis showed that age ≥60 years (odds ratio [OR], 7.11; 95% confidence interval [CI], 1.92 to 26.41), alcohol consumption (OR, 4.43; 95% CI, 1.03 to 19.19) and F/U cholesterol levels ≥200 mg/dL (OR, 5.03; 95% CI, 1.32 to 19.17) were significant risk factors for the development of RE. There was no significant difference in the development of GERD symptoms or weight according to H. pylori status during the 2-year F/U.

Conclusions

Eradication of H. pylori did not affect the development of reflux esophagitis or GERD symptoms among patients in outpatient gastroenterology clinics in South Korea.     

The Effects of Broccoli Sprout Extract Containing Sulforaphane on Lipid Peroxidation and Helicobacter pylori Infection in the Gastric Mucosa

Background/Aims

The aims of this study were to investigate whether a broccoli sprout extract containing sulforaphane (BSES) inhibited the Helicobacter pylori infection density and exerted an antioxidative effect on gastric mucosal damage.

Methods

The enrolled subjects were randomized in a double-blinded manner into three groups. Finally, 33 H. pylori (+) BSES treatment subjects (group A), 28 H. pylori (+) placebo subjects (group B), and 28 H. pylori (−) BSES treatment subjects (group C) were studied. H. pylori infection density was indirectly quantified by a ¹³C-urea breath test (UBT), and the ammonia concentration in gastric juice aspirates was measured through gastroscopic examination. Malondialdehyde (MDA), an oxidative damage biomarker, and reduced glutathione (GSH), an antioxidant biomarker, were measured in the gastric mucosa by an enzyme-linked immunosorbent assay.

Results

BSES treatment did not significantly affect the UBT values or ammonia concentration in group A (p=0.634 and p=0.505, respectively). BSES treatment did significantly reduce mucosal MDA concentrations in group A (p<0.05) and group C (p<0.001), whereas the gastric mucosal GSH concentrations did not differ before and after treatment in any of the groups.

Conclusions

BSES did not inhibit the H. pylori infection density. However, BSES prevented lipid peroxidation in the gastric mucosa and may play a cytoprotective role in H. pylori-induced gastritis.     

Prevalence of plasmid-mediated quinolone resistance genes among ciprofloxacin-nonsusceptible Escherichia coli and Klebsiella pneumoniae isolated from blood cultures in Korea

OBJECTIVES:

To analyze the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants in ciprofloxacin-nonsusceptible Escherichia coli and Klebsiella pneumoniae isolated from patients at a tertiary care hospital in Korea.

METHODS:

A total of 102 nonduplicate isolates of ciprofloxacin-intermediate or ciprofloxacin-resistant E coli (n=80) and K pneumoniae (n=22) from blood cultures were obtained. The qnr (qnrA, qnrB, qnrS), aac(6′)-Ib-cr, qepA and oqxAB genes were detected using polymerase chain reaction (PCR) and confirmed using direct sequencing. To determine whether the PMQR-positive plasmid was horizontally transferable, conjugation experiments were performed.

RESULTS:

Of the 102 isolates, 81 (79.4%) had one or more PMQR genes; these consisted of 59 (73.8%) E coli and 22 (100%) K pneumoniae isolates. The qnr genes were present in 15 isolates (14.7%): qnrB4 was detected in 10.8% and qnrS1 was detected in 3.9%. The aac(6′)-Ib-cr, qepA and oqxAB genes were detected in 77.5%, 3.9% and 10.8%, respectively. In conjugation experiments, PMQR genes were successfully transferred from seven (8.6%) isolates. The range of minimum inhibitory concentrations of ciprofloxacin for these seven transconjugants increased to 0.5 mg/L to 1 mg/L, which was 16- to 33-fold that of the recipient E coli J53 bacteria.

CONCLUSIONS:

PMQR genes were highly prevalent among ciprofloxacin-nonsusceptible E coli and K pneumoniae from blood cultures in the authors’ hospital. Therefore, it is necessary to monitor for the spread of PMQR genes of clinical isolates and to ensure careful antibiotic use in a hospital setting.     

Coagulase-negative Staphylococcus,catheter-related,bloodstream infections and their association with acute phase markers of inflammation in the intensive care unit: An observational study

OBJECTIVE:

To examine the relationship between the isolation of coagulase-negative Staphylococcus in blood cultures and acute phase markers of inflammation.

METHODS:

The present study was a prospective observational analysis conducted at three medical/surgical intensive care units (ICUs) involving adult patients with an expected ICU stay of more than 24 h duration.

RESULTS:

Of the 598 patients enrolled, 573 developed suspected bloodstream infection and 434 (72.6%) had blood cultures sent 24 h after ICU admission; 142 were excluded due to positive cultures from other sites. Of the remaining 292 patients, 31 (10.7%) grew coagulase-negative Staphylococcus, 59 (20.2%) grew known pathogenic organisms and 202 (69.2%) did not grow any organisms in their blood cultures. Twenty-five patients without suspicion of infection served as the control group. Interleukin (IL)-6, procalcitonin (PCT) and C-reactive protein (CRP) levels were highest among the known pathogen group (IL-6 271.8 U/L, PCT 4.6 U/L and CRP 164 mg/L), were similar between the coagulase-negative Staphylococcus and negative culture groups (IL-6 67.0 U/L versus 61.4 U/L [P=1.00]; PCT 1.0 U/L versus 0.9 U/L [P=0.80]; and CRP 110 mg/L versus 103 mg/L [P=0.75]), and were lowest in the control group (IL-6 31.0 U/L, PCT 0.2 U/L and CRP 41.0 mg/L). In the coagulase-negative Staphylococcus group, patients who died by day 28 had increased inflammatory bio-marker levels compared with survivors, although the differences were not statistically significant.

CONCLUSIONS:

Coagulase-negative Staphylococcus isolated from blood cultures were associated with lower levels of inflammation compared with bloodstream infections due to known pathogens and were comparable with levels in patients with negative cultures.     

Helicobacter pylori infection: Is sequential therapy superior to standard triple therapy? A single-centre Italian study in treatment-naive and non-treatment-naive patients

BACKGROUND:

Clarithromycin resistance has decreased the eradication rates of Helicobacter pylori.

AIMS:

To determine whether a 10-day course of sequential therapy (ST) is more effective at eradicating H pylori infection than triple therapy (TT) in the first or second line, and to assess side effects and compliance with therapy.

METHODS:

One hundred sixty treatment-naive and 40 non-treatment-naive patients who were positive for H pylori infection by ¹³C-urea breath test or endoscopy were enrolled. Eighty of 160 patients underwent TT, while 80 of 160 underwent ST with omeprazole (20 mg) plus amoxicillin (1 g) twice/day for five days, followed by omeprazole (20 mg) with tinidazole (500 mg) twice/day and clarithromycin (500 mg) twice/day for five consecutive days. H pylori eradication was evaluated by ¹³C-urea breath test no sooner than four weeks after the end of treatment.

RESULTS:

Eradication was achieved in 59 of 80 treatment-naive patients treated with TT (74%), in 74 of 80 patients treated with ST (93%), and in 38 of 40 non-treatment-naive patients (95%). Eradication rates in treatment-naive patients with ST were statistically significantly higher than TT (92.5% versus 73.7%; P=0.0015; OR 4.39 [95% CI 1.66 to 11.58]). Mild adverse effects were reported for both regimens.

CONCLUSIONS:

ST appears to be a well-tolerated, promising therapy; however, randomized controlled trials with larger and more diverse sample populations are needed before it can be recommended as a first-line treatment.     

The Efficacy of Moxifloxacin-Containing Triple Therapy after Standard Triple,Sequential, or Concomitant Therapy Failure for Helicobacter pylori Eradication in Korea

Background/Aims

Retreatment after initial treatment failure for Helicobacter pylori is very challenging. The purpose of this study was to evaluate the efficacies of moxifloxacin-containing triple and bismuth-containing quadruple therapy.

Methods

A total of 151 patients, who failed initial H. pylori treatment, were included in this retrospective cohort study. The initial regimens were standard triple, sequential, or concomitant therapy, and the efficacies of the two following second-line treatments were evaluated: 7-day moxifloxacin-containing triple therapy (rabeprazole 20 mg twice a day, amoxicillin 1,000 mg twice a day, and moxifloxacin 400 mg once daily) and 7-day bismuth-containing quadruple therapy (rabeprazole 20 mg twice a day, tetracycline 500 mg 4 times a day, metronidazole 500 mg 3 times a day, and tripotassium dicitrate bismuthate 300 mg 4 times a day).

Results

The overall eradication rates after moxifloxacin-containing triple therapy and bismuth-containing quadruple therapy were 69/110 (62.7%) and 32/41 (78%), respectively. Comparison of the two regimens was performed in the patients who failed standard triple therapy, and the results revealed eradication rates of 14/28 (50%) and 32/41 (78%), respectively (p=0.015). The frequency of noncompliance was not different between the two groups, and there were fewer adverse effects in the moxifloxacin-containing triple therapy group (2.8% vs 7.3%, p=0.204 and 25.7% vs 43.9%, p=0.031, respectively).

Conclusions

Moxifloxacin-containing triple therapy, a recommended second-line treatment for initial concomitant or sequential therapy failure, had insufficient efficacy.     

A preliminary guideline for the assignment of methicillin-resistant Staphylococcus aureus to a Canadian pulsed-field gel electrophoresis epidemic type using spa typing

BACKGROUND

Increasing rates of methicillin-resistant Staphylococcus aureus (MRSA) infections on a global scale is a major health concern. In Canada, there are 10 known epidemic types of MRSA as determined by pulsed-field gel electrophoresis (PFGE). Despite the excellent discriminatory power of PFGE, there are several disadvantages of using this technique, such as high degree of labour intensity and the inability to easily develop an MRSA typing database due to the subjective interpretation of results.

OBJECTIVES

The purpose of the present study was to determine whether spa typing, an established DNA sequence-based typing method, could be used as an alternative to PFGE for the typing of Canadian MRSA (CMRSA) epidemic isolates.

RESULTS

spa types were determined for 1488 CMRSA isolates, and the method was analyzed for its ability to identify and cluster CMRSA1-10 strains. Minimal spanning tree analysis of 1452 spa types revealed individual clonal clusters for PFGE epidemic types CMRSA1, 2, 7 and 8, but spa typing could not distinguish CMRSA5 from CMRSA9 and CMRSA10, and CMRSA3 from CMRSA4 and CMRSA6. However, specific spa types were generally associated with only one PFGE epidemic type. Based on these results, a spa typing guideline for CMRSA isolates was developed and tested using the first 300 MRSA isolates received in 2007 through the Canadian Nosocomial Infection Surveillance Program.

CONCLUSIONS

The high concordance of spa types with PFGE epidemic types using this guideline demonstrated the feasibility of spa typing as a more rapid and less technically demanding alternative typing method for MRSA in Canada.     

Differences in antimicrobial susceptibility in Escherichia coli from Canadian intensive care units based on regional and demographic variables

OBJECTIVES

Escherichia coli resistance to antimicrobials varies according to many factors. E coli isolates from Canadian intensive care units (ICUs) were studied to determine the distribution and demographics associated with antimicrobial resistance in this population.

METHODS

The Canadian National Intensive Care Unit (CAN-ICU) study characterized pathogens isolated in Canadian ICUs from July 2005 to June 2006. E coli susceptibility to 10 antimicrobials was determined and a multivariate logistic regression model was designed to determine whether region, sex, isolation from a sterile site and age (younger than 30 years) were significantly associated with susceptibility to the tested antimicrobials, to multidrug resistance or pan-susceptibility.

RESULTS

Four hundred ninety-three E coli isolates, representing 12.6% of all isolates collected in the CAN-ICU study were examined. Susceptibilities were highest for meropenem and tigecycline (100%), cefepime (98.2%), piperacillin-tazobactam (97.0%), ceftriaxone (93.1%) and gentamicin (92.3%), and lowest for cefazolin (76.7%), trimethoprim-sulfamethoxazole (75.7%) and the fluoroquinolones (ciprofloxacin, 78.3%; and levofloxacin, 78.9%). In the multivariate model, fluoroquinolone resistance was lowest in patients younger than 30 years of age. Cefazolin and ceftriaxone susceptibility was lowest in Nova Scotia. Susceptibility to all tested antimicrobials was lowest in Nova Scotia and British Columbia. Isolation from a sterile site was associated with trimethoprim-sulfamethoxazole, piperacillin-tazobactam and multidrug resistance.

CONCLUSIONS

E coli antimicrobial susceptibility varies across Canadian ICUs. Age, region and site of infection should be considered when prescribing empirical antimicrobial therapy. For infections caused by or suspected to be caused by E coli, fluoroquinolones, cefazolin and sulfonamides should be avoided due to low susceptibilities. Local antimicrobial prescribing practices, in particular the liberal use of fluoroquinolones and cephalosporins, and inadequate infection control practices are likely reducing susceptibility rates.     

Molecular identification and susceptibility pattern of clinical Nocardia species: Emergence of Nocardia crassostreae as an agent of invasive nocardiosis

BACKGROUND:

Nocardia species are rare, opportunistic organisms that cause disease in both immunocompetent and immunocompromised individuals.

OBJECTIVE:

To investigate the clinical presentations of various Nocardia infections based on the 16S ribosomal RNA gene of the isolate, as well as related risk factors and susceptibility patterns to antimicrobial agents

METHODS:

Thirteen patients with a diagnosis of nocardiosis were included in the present study. Seven Nocardia species were identified by 16S ribosomal RNA. Susceptibility testing was performed using six antimicrobial agents.

RESULTS:

Five patients were immunocompromised, and eight were immunocompetent with predisposing factors including cystic fibrosis, tuberculosis and ophthalmic infections. Nocardia caused pulmonary infections in eight patients (61.5%), invasive systemic infections in three patients (23%) and local (ophthalmic) infections in two patients (15.4%). In the patients with pulmonary disease, nocardiosis was caused by six species (Nocardia cyriacigeorgica, Nocardia otitidiscaviarum, Nocardia farcinica, Nocardia carnea, Nocardia testacea and Nocardia asiatica). The seventh species identified in the present study was Nocardia crassostreae.

DISCUSSION:

N crassostreae is a multidrug-resistant organism that was reported to be an emerging human pathogen causing invasive nocardiosis in a patient with non-Hodgkin’s lymphoma. N farcinica was isolated from blood in a patient with breast cancer. None of the Nocardia isolates were resistant to linezolid. One N otitidiscaviarum isolate was a multidrug-resistant organism. All patients in the present study were treated with the appropriate antibiotics and their condition resolved without further sequelae.

CONCLUSIONS:

The present study is the first report on N crassostreae as a human pathogen. The detection of multidrug-resistant species necessitate molecular identification and susceptibility testing, and should be performed for all Nocardia infections. Nocardiosis manifests various clinical features depending on the Nocardia species and underlying conditions.     

Repellent activity of herbal essential oils against Aedes aegypti (Linn.) and Culex quinquefasciatus (Say.)

Objective

To determine the mosquito repellent activity of herbal essential oils against female Aedes aegypti and Culex quinquefasciatus.

Methods

On a volunteer''s forearm, 0.1 mL of each essential oil was applied to 3 cm×10 cm of exposed skin. The protection time was recorded for 3 min after every 30 min.

Results

Essential oil from clove oil in olive oil and in coconut oil gave the longest lasting period of 76.50 min and 96.00 min respectively against Aedes aegypti. The citronella grass oil in olive oil, citronella grass oil in coconut oil and lemongrass oil in coconut oil exhibited protection against Culex quinquefasciatus at 165.00, 105.00, and 112.50 min respectively.

Conclusions

The results clearly indicated that clove, citronella and lemongrass oil were the most promising for repellency against mosquito species. These oils could be used to develop a new formulation to control mosquitoes.