Clinical evaluation of the Copan ESwab for methicillin-resistant Staphylococcus aureus detection and culture of wounds

The screening for and diagnosis of bacteriological infections often involves the collection and transportation of swab samples. The Copan ESwab was compared with the dry cotton Copan swab for methicillin-resistant Staphylococcus aureus (MRSA) screening (n = 200 paired samples) and with the Amies agar gel swab (Copan) for the sampling of burn and orthopaedic wounds (n = 203 paired samples) in terms of Gram staining and bacterial recovery. Gram stains performed with ESwab liquid showed significantly more Gram-negative rods, streptococci, Gram-positive cocci, Gram-positive rods, polymorphonuclear cells, lymphocytes and red blood cells than Gram stains from dry swabs. Bacterial recovery was significantly higher with ESwab (p < 0.01, for both MRSA screening and wounds, quantitative/semi-quantitative method). This lead to a slightly higher detection rate of MRSA (128 vs. 124 MRSA-positive ESwabs and dry swabs, respectively, p = 0.50) and a higher detection rate of coagulase-negative Staphylococcus spp. (44 isolates with ESwab vs. 29 with Amies gel swab, p = 0.001) and Enterococcus spp. (15 isolates with ESwab vs. 7 isolates with Amies gel swab, p = 0.005) with ESwab (quantitative method). We confirmed that ESwab has a high performance for Gram stains and a higher bacterial recovery than dry and Amies gel swabs when using clinical samples for MRSA screening and wound sampling.     

Distribution of <Emphasis Type="Italic">emm</Emphasis> types in invasive and non-invasive group A and G streptococci

Our study describes the emm type distributions of invasive and non-invasive group A streptococci (GAS) and group G streptococci (GGS) strains in one of the biggest Health Districts in Finland. A total of 571 GAS or GGS were recovered from patients with invasive or non-invasive infections during a 1-year period in 2008–2009 in Pirkanmaa Health District in Finland. We describe here the emm type distributions of GAS and GGS collected from throat (n = 246), pus (n = 217), deep tissue (n = 56) and blood (n = 52). The most common emm types among GAS were emm77, emm1, emm28, emm89 and emm12. Among GGS, the most common emm types were stG480, stG643, stG6, stC6979 and stG485. Some emm types were found to associate with certain infection focus. In GAS, emm77 associated with pus isolates, whereas emm1 and emm12 were more frequent among throat isolates. In GGS, stG480 was more commonly found from throat isolates.     

<Emphasis Type="Italic">Streptococcus pneumoniae</Emphasis> skin and soft tissue infections: characterization of causative strains and clinical illness

Streptococcus pneumoniae is an uncommon cause of skin and soft tissue infections, yet the incidence and clinical significance of its isolation in samples of skin or soft tissues in unselected hospital samples is poorly understood. In the present study, a review was conducted of the records of all patients with skin and soft tissue infections due to S. pneumoniae at a university hospital between January 1994 and December 2005. The isolates were identified by standard methods and were serotyped, and susceptibility testing was performed by the broth microdilution method following the guidelines of the Clinical and Laboratory Standards Institute. During the study period, 3,201 isolates of S. pneumoniae were recovered from several sources. Of these, 69 (2.2%) were from skin and soft tissue samples (69 patients). Complete information could not be obtained for 13 patients. Of the 56 patients remaining, 36 (64.3%) were infected and fulfilled the inclusion criteria. The following types of infections were observed: surgical wound infection (n = 11), burn infection (n = 7), pyomyositis (n = 6), cellulitis (n = 4), perineal or scrotal abscess (n = 3), and other (n = 5). Thirty-one (86%) patients had a favorable outcome, and 5 (13.8%) patients died. Mortality was directly attributable to S. pneumoniae infection in three of the five fatal cases. Of the 39 S. pneumoniae isolates obtained (36 from skin and soft tissues, three from blood cultures), 58.9% were penicillin nonsusceptible, 7.7% were cefotaxime nonsusceptible, and 20.5% were erythromycin resistant. The most frequent serotypes were 3, 19, 11, and 23. Of the overall number of isolates of S. pneumoniae recovered in a general institution, 2.2% involved skin and soft tissues (of which 64% were clinically significant). Mortality due to pneumococcal skin and soft tissue infections was low. R. Pallarés, coordinator (e-mail: rpallares@bell.ub.es)     

Prevalence of toxin genes in consecutive clinical isolates of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> and clinical impact

Even if Panton–Valentine leukocidin (PVL), toxic shock syndrome toxin-1 (TSST-1), staphylococcal enterotoxins (SEB and SEC), and exfoliative toxins (ETA and ETB) may be associated with severe infections, the clinical significance of their presence in clinical isolates of Staphylococcus aureus remains poorly documented. In this study, we evaluated the prevalence of toxin genes and the relationship between their presence and the severity of infection. We screened for the presence of these six toxin genes among 186 consecutive S. aureus clinical isolates (resistant or not to methicillin) during a two-month period. We compared the toxin gene profile between strains recovered from patients presenting uncomplicated infections (n = 151) and from patients suffering from severe infections (n = 35). At least one toxin gene was detected in 55 (29.6%) isolates as follows: pvl (n = 1), tst + sec (n = 5), seb (n = 19), seb + sec (n = 1), sec (n = 28), and eta (n = 1). The proportion of toxin-producing strains among patients with uncomplicated infections (27.8%) and patients with severe infections (37.1%) was not statistically different (p = 0.3044), even if the severity of infection tended to be associated with the presence of sec (p = 0.0655). Although the prevalence of toxin genes was relatively high herein, no statistically significant association between the severity of infection and the presence of toxin genes was observed.     

Reduction in catheter-related bloodstream infections in critically ill patients through a multiple system intervention

In this study, we aimed to determine the utility of a multiple system intervention to reduce catheter-related bloodstream infections (CR-BSI) in our intensive care unit (ICU). A prospective cohort study was undertaken in the medical and surgical ICU at a university hospital. We applied five measures: educational sessions about inserting and maintaining central venous catheters, skin cleaning with chlorhexidine, a checklist during catheter insertion, subclavian vein insertion and avoiding femoral insertion whenever possible, and removing unnecessary catheters. We determined the rate of CR-BSI per 1,000 catheter-days during the intervention (March to December 2007) and compared it with the rate during the same period in 2006 in which we applied only conventional preventive measures. CR-BSI was defined as the recovery of the same organism (same species, same antibiotic susceptibility profile) from catheter tip and blood cultures. We registered 4,289 patient-days and 3,572 catheter-days in the control period and 4,174 patient-days and 3,296 catheter-days in the intervention period. No significant differences in the number of patients with central venous catheters during the two periods were observed: catheters were used in 81.5% of patients during the control period and in 80.6% of patients during the intervention period. During the control period, 24 CR-BSI were diagnosed (6.7/1,000 catheter-days); during the intervention period, 8 CR-BSI were diagnosed (2.4/1,000 catheter-days) (relative risk 0.36; 95% confidence interval [CI] 0.16 to 0.80; p = 0.015). Nurses interrupted the procedure to correct at least one aspect when completing the checklist in 17.7% of insertions. In conclusion, a multiple system intervention applying evidence-based measures reduced the incidence of CR-BSI in our ICU.     

When the resistance gets clingy: Pseudomonas aeruginosa harboring metallo-β-lactamase gene shows high ability to produce biofilm

The ability to produce biofilm and the presence of metallo-β-lactamase (MBL) among Pseudomonas aeruginosa isolates were evaluated. A total of 91 isolates were recovered from sputa of patients with (CF, n = 44) and without (non-CF, n = 47) cystic fibrosis diagnosis. Seventy-nine (86.8%; 95% CI 78.3–92.3%) were biofilm producers. Interestingly, all isolates harboring MBL showed ability (most strong or moderate) to produce biofilm in vitro. We alert to an “overlapping of mechanisms” that together represent an even greater challenge for the treatment of pulmonary infections by P. aeruginosa.     

High prevalence of ST121 in community-associated methicillin-susceptible Staphylococcus aureus lineages responsible for skin and soft tissue infections in Portuguese children

In order to evaluate the incidence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in Portugal, we analyzed a collection of 38 S. aureus isolates recovered from 30 children attending the pediatric emergency department of a central hospital in Lisbon due to skin and soft tissue infections. Molecular characterization identified seven clonal lineages among the 35 methicillin-susceptible S. aureus (MSSA) isolates, of which the major lineage PFGE A/t159/ST121 included 63% of the isolates. The three MRSA isolates belonged to the Pediatric clone PFGE D/t535/ST5-IV (n = 2) and to the European CA-MRSA clone PFGE G/t044/ST80-IVc (n = 1). All isolates harbored several virulence factors, namely, leukocidins. Panton–Valentine leukocidin (PVL) was produced by isolates from five MSSA lineages and by the ST80 MRSA. Of interest, this is the first reported isolation of CA-MRSA ST80 in Portugal.     

<Emphasis Type="Italic">Blastocystis hominis</Emphasis> infection in long-term care facilities in Taiwan: prevalence and associated clinical factors

Blastocystis hominis is probably the most common protozoan found in the human gut worldwide. In Taiwan, the prevalence of B. hominis infection is yet to be determined but is expected to be relatively higher among foreign workers. No data is available on the prevalence of B. hominis infection in long-term care facilities in Taiwan. This study included 713 subjects (552 residents and 161 care workers) from ten long-term care facilities in Taiwan who completed stool microscopic examinations with Merthiolate-iodine-formalin stain technique. The prevalence rate of blastocystosis was the highest among foreign and domestic care workers followed by residents (12.2%, 4.6%, and 2.7%, respectively). Older age (p = 0.04) and lower educational level (p = 0.008) were significantly associated with blastocystosis among care workers. Among residents, B. hominis infection was negatively associated with prolonged use of antibiotics within 3 months prior to examination (p = 0.05) and positively associated with tracheostomy in-place (p = 0.028). In conclusion, B. hominis infection was the most prevalent intestinal parasitic infection among both care workers and residents of long-term care facilities in Taiwan. Use of antibiotics was negatively associated with B. hominis infection among residents. Additionally, appropriate preventive measures should be implemented to older care workers with lesser educational attainment in order to reduce the risk of blastocystosis infection.     

Bacteremia caused by <Emphasis Type="Italic">Brevundimonas</Emphasis> species at a tertiary care hospital in Taiwan, 2000–2010

We investigated clinical and microbiological characteristics of 30 patients with Brevundimonas bacteremia treated at a tertiary care hospital in Taiwan during 2000–2010. All the 30 bacteria isolates were confirmed to the species level by 16S rRNA sequencing analysis. Minimum inhibitory concentrations (MICs) of 11 antimicrobial agents against these isolates were determined by the agar dilution method. Seventeen (57%) patients had underlying malignancy, 12 (40%) had undergone central catheter placement, and 13 (43%) had received chemotherapy within the previous three months. Eight (27%) patients had community-acquired bacteremia and the remaining 22 patients (73%) had healthcare-associated bacteremia. The overall 14-day and 30-day mortality rates were 13% and 17%, respectively. Among the 30 isolates, B. vesicularis constituted most commonly (n = 22, 63%), followed by B. nasdae (n = 5) and B. diminuta (n = 3). All isolates were susceptible to piperacillin-tazobactam and amikacin, while all were resistant to ciprofloxacin and colistin. Tigecycline (MICs at which 90% of isolates are inhibited [MIC₉₀] was 0.12 mg/L) and doripenem (MIC₉₀ of 1 mg/L) both possessed good in vitro activities. In conclusions, Brevundimonas should be considered a pathogen that can cause bacteremia in immunocompromised hosts. Piperacillin-tazobactam, amikacin, doripenem, and tigecycline exhibit good in vitro activities against these ciprofloxacin- and colistin-resistant Brevundimonas species.     

Anti-<Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> Antibodies are Frequent in Type 1 Diabetes

Anti-Saccharomyces cerevisiae antibodies (ASCA) have been described in many autoimmune diseases in which there is an increased intestinal permeability. Also in type 1 diabetes (T1D), there is an increased intestinal permeability. Since no data are available about ASCA in T1D, we evaluated, retrospectively, the frequency of ASCA in this disease. ASCA, IgG, and IgA, were determined by ELISA in sera of 224 T1D patients in which coeliac disease has been excluded and 157 healthy control group. The frequency of ASCA (IgG or IgA) was significantly higher in T1D patients than in the control group (24.5% vs. 2.5%, p < 10⁻⁷). The same observation was found in children and in adult patients when we compare them to healthy children and blood donors group respectively. Compared to children, adult patients with T1D showed significantly higher frequencies of ASCA of any isotype (38% vs. 13.7%, p < 10⁻⁴), both ASCA IgG and IgA (12% vs. 1.6%, p = 0.002), ASCA IgG (35% vs. 9.8%, p < 10⁻⁵) and ASCA IgA (15% vs. 5.6%, p = 0.001). The frequency of ASCA was statistically higher in females of all T1D than in males (30.8% vs.17.7%, p = 0.03), in girls than in boys (22% vs.6.2%, p = 0.017), and significantly higher in men than in boys (35.7% vs. 6.2%, p < 10⁻⁴). The frequency of ASCA IgG was significantly higher than that of ASCA IgA in all T1D patients (21% vs. 9.8%, p < 0.002), in all females (26.5% vs. 10.2%, p < 0.002), in women (37.9% vs. 12%, p < 0.001). The frequency of ASCA was significantly higher in all long-term T1D than in an inaugural T1D (29% vs. 14.5%, p = 0.019). The same observation was found in adults (45.8% vs. 17.8%, p = 0.01). In long-term T1D patients, ASCA were significantly more frequent in adults than children (45.8% vs. 14.5%, p < 10⁻⁴). The frequency of ASCA IgG was significantly higher in long-term T1D than in an inaugural T1D (25.2% vs. 11.6%, p = 0.03). Patients with T1D had a high frequency of ASCA.     

Influence of azithromycin and clarithromycin on macrolide susceptibility of viridans streptococci from the oral cavity of healthy volunteers

Oral viridans streptococci are a reservoir of resistance genes for pathogens. Through prolonged exposure, long-acting macrolides (e.g., azithromycin) may induce the resistance of the commensals to macrolides more frequently than macrolides with a shorter half-life (e.g., clarithromycin). In a prospective, randomized, evaluator-blinded trial in healthy volunteers receiving standard courses of either azithromycin (n = 20) or clarithromycin (n = 20), we compared the susceptibility of oral viridans streptococci to macrolides over a period of 12 weeks. There was a significant temporal increase in the numbers of resistant isolates in both groups (p < 0.0005 at week 1). The proportion of macrolide-resistant isolates over time was significantly higher following azithromycin treatment (p = 0.0005), but returned to baseline values until week 12 in both groups. Temporal differential effects of azithromycin and clarithromycin on the induction of resistance were observed and need to be investigated regarding their effect on co-colonizing pathogens.     

Prognostic value of procalcitonin in <Emphasis Type="Italic">Legionella</Emphasis> pneumonia

The diagnostic reliability and prognostic implications of procalcitonin (PCT) (ng/ml) on admission in patients with community-acquired pneumonia (CAP) due to Legionella pneumophila are unknown. We retrospectively analysed PCT values in 29 patients with microbiologically proven Legionella-CAP admitted to the University Hospital Basel, Switzerland, between 2002 and 2007 and compared them to other markers of infection, namely, C-reactive protein (CRP) (mg/l) and leukocyte count (10⁹/l), and two prognostic severity assessment scores (PSI and CURB65). Laboratory analysis demonstrated that PCT values on admission were >0.1 in over 93%, >0.25 in over 86%, and >0.5 in over 82% of patients with Legionella-CAP. Patients with adverse medical outcomes (59%, n = 17) including need for ICU admission (55%, n = 16) and/or inhospital mortality (14%, n = 4) had significantly higher median PCT values on admission (4.27 [IQR 2.46–9.48] vs 0.97 [IQR 0.29–2.44], p = 0.01), while the PSI (124 [IQR 81–147] vs 94 [IQR 75–116], p = 0.19), the CURB65 (2 [IQR 1–2] vs 1 [1–3], p = 0.47), CRP values (282 [IQR 218–343], p = 0.28 vs 201 [IQR 147–279], p = 0.28), and leukocyte counts (12 [IQR 10–21] vs 12 [IQR 9–15], p = 0.58) were similar. In receiver operating curves, PCT concentrations on admission had a higher prognostic accuracy to predict adverse outcomes (AUC 0.78 [95%CI 0.61–96]) as compared to the PSI (0.64 [95%CI 0.43–0.86], p = 0.23), the CURB65 (0.58 [95%CI 0.36–0.79], p = 0.21), CRP (0.61 [95%CI 0.39–0.84], p = 0.19), and leukocyte count (0.57 [95%CI 0.35–0.78], p = 0.12). Kaplan-Meier curves demonstrated that patients with initial PCT values above the optimal cut-off of 1.5 had a significantly higher risk of death and/or ICU admission (log rank p = 0.003) during the hospital stay. In patients with CAP due to Legionella, PCT levels on admission might be an interesting predictor for adverse medical outcomes. Jeannine Haeuptle, Roya Zaborsky, and Rico Fiumefreddo contributed equally to this article.     

Infection level of the Asian tapeworm (<Emphasis Type="Italic">Bothriocephalus acheilognathi</Emphasis>) in the cyprinid fish, <Emphasis Type="Italic">Schizothorax niger</Emphasis>, from Anchar Lake,relative to season,sex, length and condition factor

Various studies have shown that the Asian fish tapeworm, Bothriocephalus acheilognathi causes great economic loss in hatcheries, fish farms as well as in lakes. In order to understand the seasonal variation of infection in a nutrient-enriched lake, parasitological investigation was carried out in the indigenous cyprinid fish, Schizothorax niger Heckel 1838 from September, 2008 to August, 2009. Overall, this study revealed definite seasonality of infection (p < 0.05), with greater infection in summer (prevalence = 39.5%) and lesser in winter (prevalence = 8.1%). The prevalence among different seasons revealed significant differences (p < 0.05). Sex was not an important factor influencing the prevalence of the Asian tapeworm. A strong positive correlation (Pearson’s correlation, r = 0.7; p = 0.02) between total length of S. niger and number of Asian fish tapeworms was observed. Similarly, a strong positive correlation existed between weight of fish and number of tapeworms (Pearson’s correlation, r = 0.7; p = 0.005). Prevalence and mean abundance were positively and significantly correlated with water temperature (r = 0.8, p < 0.01 and r = 0.8, p < 0.01, respectively). Thus seasonal dynamics, total length and weight of the host significantly influenced the tapeworm infection. The above findings will be useful in devising the appropriate control strategies for the Asian tapeworm in wild fish in Kashmir valley as well as in similar climatic zones of other parts of the world. Also, information from this study will be used to assess the spread and extent of B. acheilognathi which is a potential threat to the indigenous fish fauna of Anchar Lake.     

Risk factors and outcomes of Escherichia coli bacteremia caused by strains that produce CTX-M or non-CTX-M extended-spectrum-beta-lactamases

To determine whether there are differences in risk factors and outcomes among patients with E. coli bacteremia caused by strains that produce CTX-M or non-CTX-M extended-spectrum beta-lactamases. From 1 July 2005 to 30 June 2007, patients with positive blood culture of extended-spectrum β-lactamases (ESBL)-producing E. coli were reviewed. Sixty patients with ESBL-producing E. coli bacteremia were identified. These included 41 (68.3%) isolates with CTX-M β-lactamases. CTX-M-14 accounted for 31 (75.6%) and CTX-M-3 for 9 (22.0%) of the 41 CTX-M isolates. Patients with CTX-M strains were less likely, by univariate analysis, to have significant risk factors for infection including age ≥ 65 years, chronic renal insufficiency, ICU stay at bacteremia onset, central venous catheter use and mechanical ventilation. Multivariate analysis revealed that chronic renal failure and ICU stay were independent predictors. Antibiograms were similar for CTX-M and non-CTX-M producers except that CTX-M strains were significantly more susceptible to cefmetazole (92.7 vs 36.8%, p < 0.0001). The overall mortality and length of hospitalization were not significantly different between the two groups. E. coli with CTX-M β-lactamases was more likely than non-CTX-M strains to invade non-compromised patients. There were no differences in clinical outcomes between the two groups.     

Intra-arterial <Emphasis Type="Italic">tert</Emphasis>-Butyl-Hydroperoxide Infusion Induces an Exacerbated Sensory Response in the Rat Hind Limb and is Associated with an Impaired Tissue Oxygen Uptake

The objective of this study was to investigate oxidative stress and oxygen extraction mechanisms in an animal model of continuous intra-arterial infusion of a free radical donor and in an in vitro model using isolated mitochondria. tert-Butyl-hydroperoxide (tert-BuOOH, 25 mM) was infused for 24 h in the left hind limb of rats to induce soft tissue damage (n = 8). After 7 days, we assessed local sensory response, tissue oxygen consumption, oxygen radicals, and antioxidant levels. In vitro mitochondrial function was measured after stimulation of isolated mitochondria of skeletal muscle cells with increasing doses of tert-BuOOH. tert-BuOOH infusion resulted in an increased skin temperature (p = 0.04), impaired function, and a significantly increased pain sensation (p = 0.03). Venous oxygen saturation levels (p = 0.01) and the antioxidant ceruloplasmin (p = 0.04) were increased. tert-BuOOH inhibited mitochondrial function in vitro. Induction of free radical formation in the rat hind limb results in an exacerbated sensory response and is associated with impaired oxygen extraction, which likely results from mitochondrial dysfunction caused by free radicals.     

Clinical features,antimicrobial susceptibilities,and outcomes of <Emphasis Type="Italic">Elizabethkingia meningoseptica</Emphasis> (<Emphasis Type="Italic">Chryseobacterium meningosepticum</Emphasis>) bacteremia at a medical center in Taiwan, 1999–2006

A total of 118 patients with Elizabethkingia meningoseptica bacteremia at a medical center in Taiwan from 1999 to 2006 were studied. Minimum inhibitory concentrations (MICs) of 99 preserved isolates were determined. The incidence (per 100,000 admissions) of E. meningoseptica bacteremia increased from 7.5 in 1996 to 35.6 in 2006 (p = 0.006). Among them, 84% presented with fever, 86% had nosocomial infections, and 60% had acquired the infection in intensive care units (ICUs). The most common underlying diseases were malignancy (36%) and diabetes mellitus (25%). Seventy-eight percent of patients had primary bacteremia, followed by pneumonia (9%), soft tissue infection, and catheter-related bacteremia (6%). Forty-five patients (38%) had polymicrobial bacteremia. Overall, the 14-day mortality was 23.4%. Multivariate analysis revealed E. meningoseptica bacteremia acquired in an ICU (p = 0.048, odds ratio [OR] 4.23) and presence of effective antibiotic treatment after the availability of culture results (p = 0.049, OR 0.31) were independent predictors of 14-day mortality. The 14-day mortality was higher among patients receiving carbapenems (p = 0.046) than fluoroquinolones or other antimicrobial agents. More than 80% of the isolates tested were susceptible to trimethoprim-sulfamethoxzole, moxifloxacin, and levofloxacin. The MIC₅₀ and MIC₉₀ of the isolates to tigecycline and doxycycline were both 4 μg/mL and 8 μg/ml, respectively.     

Plasma 1,25 Dihydroxy Vitamin D<Subscript>3</Subscript> Level and Expression of Vitamin D Receptor and Cathelicidin in Pulmonary Tuberculosis

Introduction  Vitamin D₃, which exerts its effect through vitamin D receptor (VDR), is known for its potent immunomodulatory activities. Associations between low serum vitamin D₃ levels and increased risk of tuberculosis have been reported. Study Subjects and Methods  Plasma 1,25 dihydroxy vitamin D₃ levels (1,25(OH)₂ D₃) and ex vivo levels of VDR protein from peripheral blood mononuclear cells were studied in 65 pulmonary tuberculosis (PTB) patients and 60 normal healthy subjects (NHS) using enzyme-linked immunosorbent assay-based methods. Using real-time polymerase chain reaction (PCR), induction of VDR, cathelicidin, and CYP27B1 mRNA were studied in live Mycobacterium tuberculosis-stimulated macrophage cultures treated with or without 1,25 dihydroxy vitamin D₃. VDR and CYP27B1 (-1077 A/T) gene polymorphisms were studied using PCR-based methods. Results  1,25(OH)₂ D₃ were significantly increased (p = 0.0004), while ex vivo levels of VDR protein were significantly decreased in PTB patients (p = 0.017) as compared to NHS. 1,25(OH)₂ D₃ levels were not different between variant genotypes of CYP27B1. A trend towards decreased levels of VDR protein was observed among NHS with BsmI BB and TaqI tt genotypes compared to NHS with other genotypes. Relative quantification of mRNA using real-time PCR revealed increased VDR mRNA expression in live M. tuberculosis-stimulated culture in PTB patients (p < 0.01) than normal healthy subjects. Cathelicidin mRNA expression was significantly increased in vitamin D₃-treated cultures compared to unstimulated and M. tuberculosis-stimulated culture in both patients (p < 0.001) and NHS (p < 0.05). Conclusions  The present study suggests that PTB patients may have increased 1,25(OH)₂ D₃ levels, and this might lead to downregulation of VDR expression. Decreased VDR levels could result in defective VDR signaling. Moreover, addition of 1,25(OH)₂ D₃ might lead to increased expression of cathelicidin which could enhance the immunity against tuberculosis.     

Differentiation of <Emphasis Type="Italic">Mycobacterium kansasii</Emphasis> infection from <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> infection: comparison of clinical features,radiological appearance,and outcome

This retrospective study sought to systematically identify clinical and radiological features differentiating Mycobacterium kansasii from Mycobacterium tuberculosis infection. The sample included matched patients with a culture-positive diagnosis of M. tuberculosis infection (n = 121) or M. kansasii infection (n = 62) derived from the databases of two tuberculosis centers. Data on patient background and clinical features were collected, and chest radiographs were analyzed. Sixty percent of the M. kansasii group were native Israelis compared to 15% of the M. tuberculosis group (p = 0.0001). M. tuberculosis infection was associated with a higher rate of human immunodeficiency virus (HIV) infection (p = 0.03) and M. kansasii infection with a higher rate of lung disease (p = 0.0001). M. tuberculosis infection was characterized by a higher likelihood of bilateral disease (p = 0.005), pleural effusions, and lymphadenopathy (p = 0.006 and p = 0.001, respectively). There were ten deaths, all in the M. tuberculosis group. On multivariate logistic regression, the presence of chronic obstructive pulmonary disease and associated lung disease were significant predictors of M. kansasii infection. The findings show that there are group differences between the clinical features of the two infections. In the setting of pulmonary mycobacterial infection, the presence of coinfection with HIV, bilateral disease, pleural effusion, and lymphadenopathy make M. kansasii infection very unlikely.     

Extended-spectrum β-lactamase-producing Shigella strains in Israel, 2000–2004

Routine susceptibility testing of 5,616 Shigella isolates at the National Shigella Reference Centre in Israel over a 5-year period (2000–2004) revealed resistance to ceftriaxone in one strain of Shigella boydii 2 and in two strains each of Shigella flexneri 2a, S. flexneri 6, and Shigella sonnei. All seven isolates were confirmed as producers of extended-spectrum β-lactamase (ESBL) by the combination disk method, the Vitek 1 system, and a modification of the double-disk synergy test, which is based on the inhibitory properties of clavulanic acid, tazobactam, and sulbactam. Tazobactam had the strongest effect in all seven strains. Molecular characterization of the ESBLs identified CTX-M-type enzymes, consisting of the CTX-M-9 group (n = 3), CTX-M-3 (n = 2), CTX-M-39 (n = 1), and CTX-M-2 group (n = 1). Three of the strains also carried bla-_OXA genes and a bla-_TEM gene. Although the prevalence of ESBLs in this study was low, further research is needed on the spread and transfer of resistance genes, both in hospitals and in the community.     

In vitro antiplasmodial activity and cytotoxicity of crude extracts and compounds from the stem bark of <Emphasis Type="Italic">Kigelia africana</Emphasis> (Lam.) Benth (Bignoniaceae)

In order to assess the potential of the stem bark of Kigelia africana (Lam.) Benth as source of new anti-malarial leads, n-hexane and ethyl acetate (EtOAc) extracts and four compounds isolated from the stem bark were screened in vitro against the chloroquine-resistant W-2 and two field isolates of Plasmodium falciparum using lactate dehydrogenase assay. The products were also tested for their cytotoxicity on LLC/MK2 monkey kidney cells. The EtOAc extract exhibited a significant antiplasmodial activity (IC₅₀ = 11.15 μg/mL on W-2; 3.91 and 4.74 μg/mL on field CAM10 and SHF4 isolates, respectively), whereas the n-hexane fraction showed a weak activity (IC₅₀ = 73.78 μg/mL on W-2 and 21.85 μg/mL on SHF4). Three out of the four compounds showed good activity against all the three different parasite strains (IC₅₀ < 5 μM). Specicoside exhibited the highest activity on W-2 (IC₅₀ = 1.54 μM) followed by 2β, 3β, 19α-trihydroxy-urs-12-en-28-oic acid (IC₅₀ = 1.60 μM) and atranorin (IC₅₀ = 4.41 μM), while p-hydroxycinnamic acid was the least active (IC₅₀ = 53.84 μM). The EtOAc extract and its isolated compounds (specicoside and p-hydroxycinnamic acid) were non-cytotoxic (CC₅₀ > 30 μg/mL), whereas the n-hexane extract and two of its products, atranorin and 2β, 3β, 19α-trihydroxy-urs-12-en-28-oic acid showed cytotoxicity at high concentrations, with the last one being the most toxic (CC₅₀ = 9.37 μg/mL). These findings justify the use of K. africana stem bark as antimalaria by traditional healers of Western Cameroon, and could constitute a good basis for further studies towards development of new leads or natural drugs for malaria.