Extended-spectrum ß-lactamase-producing Enterobacteriaceae: in vitro susceptibility to fosfomycin, nitrofurantoin and tigecycline.

OBJECTIVE: To assess the susceptibility trends of community-acquired extended-spectrum ß-Iactamase (ESBL)-producing urinary isolates with particular reference to fosfomycin, nitrofurantoin and tigecycline. MATERIALS AND METHODS: Seven hospitals across the United Arab Emirates participated in this study from June 2008 to March 2010. The antibiotic sensitivity of ESBL-producing uropathogens to a panel of antibiotics including tigecycline, fosfomycin and nitrofurantoin was assessed. The Hyplex ESBL identification system (h-ES-ID) was used for genotypic identification. RESULTS: Two hundred and ninety-two ESBL-producing Enterobacteriaceae isolates were identified during the study period. Of these, 182 (62%) were urinary isolates and comprised of Escherichia coli: 149 (81.9%), Klebsiella pneumoniae: 30 (16.5%) and Proteus mirabilis: 3 (1.6%). Of the 182 urinary isolates, 179 (98.3%) were from patients with community onset urinary tract infections. The h-ES-ID system identified 172 (94.5%) of the urinary isolates as CTX-M positive. All isolates were susceptible to imipenem and meropenem. Over half of the isolates showed resistance to gentamicin (98; 53.8%), trimethoprim-sulfamethoxazole (139; 76.4%) and ciprofloxacin (143; 78.6%). Sensitivity to nitrofurantoin and fosfomycin was 90 and 100%, respectively. Two CTX-M-positive K. pneumoniae isolates with tigecycline resistance (MIC >4 µg/ml) were identified. CONCLUSION: There is dissemination of CTX-M ESBL-producing urinary pathogens into the community. Fosfomycin and nitrofurantoin were active against ESBL-positive uropathogens, and emergence of tigecycline resistance needs close monitoring.

Integrated assessment of CO2-ECBM potential in Jharia Coalfield, India.

Coalbed methane (CBM) production is effectively achieved by utilizing two processes, viz. primary and secondary recovery. In this paper, the primary recovery of CBM was studied using the adsorption isotherm while CO2-ECBM process for the secondary recovery was simulated with realistic parameters. The adsorption isotherm for CH4 was drawn up to the pressure of 1200 psi for four coal samples and Langmuir isotherm curves for both CH4 and CO2 was measured for one sample up to 2000 psi. The adsorption isotherm of four samples was further utilized for finding the primary recovery factor of methane, showing that the average primary recovery is ~ 54% with the highest recovery factor of ~ 76% for one sample. Hence, CO2-ECBM process could be further implemented to enhance gas recovery. Then, a 3D heterogeneous coalbed model at a depth of 3219 ft was constructed using the COMET3 simulator to demonstrate the potential of CO2-ECBM recovery technique. A concept of break-even time was introduced in this study for the comprehension of CO2-ECBM process. It is found that coalbed reservoirs may opt to implement this technology with economically sound recovery.

222Rn Exhalation Flux Rate and 226Ra in the Soils of a Copper-Mineralised Area.

Uranium-series radionuclides exist in trace quantities in all soils and rocks on earth in variable concentrations. Among these, 222Rn gas exhaled by the soil of a geological location is the main contributor to the environmental radioactivity. A 222Rn exhalation flux study was carried out in the heavily mineralised area of the Singhbhum Copper Belt of Jharkhand, India. A significant seasonal variation in the soil gas exhalation was observed, which is attributable to the seasonal atmospheric parameters of the study area. The average 222Rn exhalation flux from the soil was estimated to be in the range of 4.5-$20.1\ \mathrm{Bq}\ {\mathrm{m}}^{-2}\ {\mathrm{s}}^{-1}$ with a mean of $10.1\pm 3.9\ \mathrm{mBq}\ {\mathrm{m}}^{-2}\ {\mathrm{s}}^{-1}$ and geometric mean (GM) of $9.5\ \mathrm{mBq}\ {\mathrm{m}}^{-2}\ {\mathrm{s}}^{-1}$. Also, 20 soil samples collected from the study area were analysed by the emanometric method, which estimated the 226Ra specific activity in the soils in the range of 9-$63\ \mathrm{Bq}\ \mathrm{k}{\mathrm{g}}^{-1}$ and a mean value of $39\pm 16\ \mathrm{Bq}\ \mathrm{k}{\mathrm{g}}^{-1}$.

Molecular typing of methicillin-resistant Staphylococcus aureus isolated in a Bahrain hospital.

OBJECTIVE: To investigate antibacterial resistance patterns and genetic relatedness of methicillin-resistant Staphylococcus aureus (MRSA) obtained at the Salmaniya Medical Complex in Bahrain. METHODS: A total of 53 consecutive MRSA isolates obtained from 53 patients were studied using antibacterial resistance patterns, coagulase gene polymorphism, staphylococcal cassette chromosome mec (SCCmec) typing and pulsed-field gel electrophoresis (PFGE). RESULTS: There was a high prevalence of resistance to fusidic acid (92.5%), ciprofloxacin (92.5%), erythromycin (90.6%), tetracycline (88.7%), trimethoprim (88.7%), streptomycin (88.7%), kanamycin (83.0%) and gentamicin (73.6%). Coagulase gene typing divided the isolates into five coagulase types comprising coagulase type 36 (86.7%), type 20 (3.8%), type 16 (3.8%), type 38 (1.9%) and type 384 (3.8%). They belonged to SCCmec type III (86.7%) and SCCmec type IV (13.3%). PFGE identified five pulsotypes (types A-E) with PFGE type A and its subtypes comprising 83% of the isolates. PFGE type A isolates were multiresistant and had the SCCmec type III and coagulase type 36 genotype. The SCCmec type IV isolates were nonmultiresistant with different genetic backgrounds. CONCLUSIONS: The study identified two types of MRSA in the hospital during the study period. One type consisted of a persistent multiresistant PFGE clone with the SCCmec type III and coagulase type 36 genotypes. The second type consisted of nonmultiresistant isolates that belonged to different genetic backgrounds and were isolated less frequently.

Studies on the mechanism of Salmonella typhimurium enterotoxin-induced diarrhoea.

The unidirectional fluxes of Na+ and Cl- were studied in Salmonella typhimurium enterotoxin-treated rats. There was net secretion of Na+ and Cl- in toxin-treated animals, while in control animals there was net absorption of these ions. In the presence of the Ca(2+)-ionophore, there was net secretion of Na+ and Cl- in the control group, while the ionophore enhanced the secretion of these ions in experimental animals. The calcium channel blocker, verapamil, decreased the secretion induced by salmonella toxin, but could not reverse the secretion to absorption. There was no difference in the net absorption of Ca2+ in both the control and experimental animals. There was a significant increase in the intracellular free calcium concentrations in enterocytes isolated from toxin-treated rat intestines as compared to that in enterocytes isolated from control animals. In the presence of PMA (phorbol-12-myristated-13-acetate) there was net secretion of Na+ and Cl- in the control group, while in the experimental group there was no change in the fluxes of these ions. The selective, potent inhibitor of protein kinase C, H-7 (1-(5-isoquinolinylsulphonyl)-2-methylpiperazine) reversed the secretion of Na+ and Cl- in the toxin-treated group to absorption. The addition of indomethacin also inhibited the secretion induced by salmonella toxin, but failed to reverse it to absorption. However, the addition both H-7 and indomethacin to the experimental group had a partial additive effect. These studies demonstrate that the Salmonella enterotoxin-mediated fluid secretion involves protein kinase C and the arachidonic acid metabolites and perhaps does not involve the extracellular calcium pools.

Calcium and protein kinase C play an important role in Campylobacter jejuni-induced changes in Na+ and Cl- transport in rat ileum in vitro.

The pathophysiological mechanism of Campylobacter jejuni (enterotoxigenic) induced secretory diarrhoea remains least understood. To investigate the mechanism(s) involved, the unidirectional fluxes of Na+ and Cl- were measured across the C. jejuni live culture infected and control (non infected) rat ileum (unstriped), in vitro by Ussing technique under short circuit conditions, in the presence or absence of: Ca2+ ionophore A23187 (5 microM), 1-verapamil (100 microM), calmodulin (CaM) antagonist W-7 (100 microM), dantrolene (25 microM), protein kinase C (PKC) activator PMA (100 ng/ml) and H-7 (60 microM), selective inhibitor of PKC. There was net absorption of Na+ and enhanced Cl- secretion in infected animals while in control animals there was net absorption of Na+ and marginal secretion Cl-.Ca2+ ionophore A23187 mimicked the effects of C. jejuni infection whereas 1-verapamil had significant antisecretory effect on Na+ and Cl- secretion in infected animals. In vitro measurement of undirectional 45Ca fluxes in Ussing chamber experiments revealed net absorption of Ca2+ in infected rat ileum as compared to net secretion of Ca2+ in control rat ileum. These observations clearly indicate that there is increased stimulation of Ca2+ uptake from extracellular milieu to the enterocytes during C. jejuni-induced diarrhoea. The intracellular calcium levels (Ca2+]i (as measured by fluorescent probe Fura-2AM) were found to be raised significantly (P < 0.0001) in enterocytes isolated from C. jejuni infected ileum as compared to the enterocytes from control ileum. The observed increase in [Ca2+]i in enterocytes isolated from C. jejuni live culture supernatant treated rat ileum further shows the involvement of enterotoxin in diarrhoeal process. Dantrolene decreased significantly C. jejuni-induced net Na+ and Cl- secretion but it could not reverse it to absorption suggesting the partial involvement of Ca2+ mobilised from intracellular stores in mediating secretion. W-7 failed to inhibit the C. jejuni-induced net Na+ and Cl- secretion. In addition the CaM activity estimated in intestinal microvillar core remained same in both the control and C. jejuni infected animals. This indicates that C. jejuni-induced diarrhoea is not mediated through the activation of Ca(2+)-CaM complex pathway of the Ca2+ messenger system. The PKC activator PMA, induced net secretion of Na+ and Cl- in the control animals but it could not enhance further the C. jejuni-induced Na+ and Cl- secretion, suggesting that there is overlapping effect of PMA and C. jejuni live culture infection.(ABSTRACT TRUNCATED AT 400 WORDS)

Long-term function and survival of elderly donor kidneys transplanted into young adults.

BACKGROUND: Traditionally, elderly donor kidneys have not been widely accepted for transplantation on the assumption of inferior performance. However, the United Network for Organ Sharing reports an increase in the number of elderly donors from less than 2% in 1982 to 24% in 1995. This trend is commensurate with the increase of older dialysis patients and an overall increase in the elderly population in the United States (1). Optimal utilization of these kidneys is essential to overcome the acute organ shortage. METHODS: In this study, we transplanted 25 kidneys from elderly donors (ages 56-72 years) into young adult recipients (ages 20-50 years) (group 1) over a 4-year period. We compared the results with matched recipients of young adult donor kidneys (group 2) with regard to long-term kidney function and graft survival. A pretransplant biopsy of elderly donor kidneys was carried out and a frozen section report was obtained. Only those kidneys showing glomerulosclerosis of less than 20% were accepted for transplantation. All cadaveric kidneys were preserved in University of Wisconsin solution. RESULTS: Pretransplant biopsies of elderly donor kidneys showed structural deficits, which included glomerulosclerosis in 85%, arteriolar and/or mesangial thickening in 75%, and interstitial lymphocyte infiltration in 30%. The mean serum creatinine was 2.4+/-0.74, 2.2+/-0.56, and 2.9+/-0.76 mg/100 ml in group 1 and 1.5+/-0.55, 2.3+/-2.24, and 1.7+/-0.62 in group 2 at 1, 3, and 5 years, respectively. The patient survival was 92%, 92%, and 88% in group 1, and 100%, 100%, and 100% in group 2 at 1, 3, and 5 years, respectively. The graft survival was 80%, 64%, and 56% in group 1 and 100%, 96%, and 88% in group 2 at similar time intervals. The differences in the serum creatinine and graft survival between the two groups were statistically significant (P < 0.05). CONCLUSIONS: Most of the elderly donor kidneys with structural deficits transplanted into young adults provided suboptimal function and inferior long-term graft survival. To maximize the utilization and optimize the survival of elderly donor kidneys, we propose transplantation of these kidneys into age-matched recipients with similar physiological requirements as those of donors, with regard to kidney function.

Speciation of presumptive viridans streptococci from early onset neonatal sepsis.

Twenty isolates resembling viridans streptococci, 16 from blood and four from gastric aspirates, from 17 cases of early onset neonatal sepsis were identified by the API20 Strep, Rapid ID 32 Strep and conventional tests plus hydrolysis of methylumbelliferyl glycoside substrates. Nineteen of the isolates were identified as species of viridans streptococci and one as a Leuconostoc sp. Ten of the isolates were Streptococcus oralis, three S. mitis biotype 1, two S. mitis biotype 2 and one each of S. sanguis, S. vestibularis, S. salivarius and S. intermedius. The Rapid ID 32 Strep and conventional plus methylumbelliferyl tests gave the same species identity for 17 of the isolates. S. intermedius was identified by the Rapid ID 32 Strep as S. constellatus and S. salivarius as S. equinus, with S. salivarius at lower probability. The API20 Strep failed to identify S. vestibularis and identified S. salivarius as S. defectivus. The absence of certain critical tests, including urea hydrolysis, does not allow the API20 Strep to identify all the currently recognised species of viridans steptococci. The species distribution was unexpected and the incidence of S. oralis and other viridans streptococci in vaginal swabs from prenatal patients is being investigated further.

Neogenesis of pancreatic endocrine cells in copper-deprived rat models.

Transplantation of progenitor cells for regeneration of islet cells could prove invaluable in the treatment of diabetes mellitus. This study provides evidence that in rats maintained on a copper-deficient diet containing the copper-chelating agent tetraethylenepentamine pentahydrochloride, regeneration of single alpha and beta endocrine cells in the ductules and acinar tissue of the adult rat pancreata occurred. These regenerated cells both in the ductules and acinar tissue stained positive for glucagon and insulin similar to cells within the islets and in addition to being reactive to proliferative cellular nuclear antigen, an intracellular marker of active proliferation. In contrast, the control group pancreata did not show any evidence of islet regeneration, proliferation, or proliferative cellular nuclear antigen reactivity pre- or posttransplantation. Transplantation of digested pancreatic tissues from the copper-deficient group into the spleen of syngeneic diabetic rats reversed diabetes, and this was confirmed histologically by demonstrating cells within ductules that stained positively for insulin. This study concludes that copper deprivation contributes to the neogenesis of pancreatic alpha and beta cells in the ductules and acinar tissue of adult pancreas in rat model and that transplanted stem cells maintain their functional capacity in the recipient after transplantation.

A case of rofecoxib-associated stevens-johnson syndrome with corneal and conjunctival changes.

PURPOSE: To report a case of rofecoxib (Vioxx)-associated Stevens-Johnson syndrome with corneal and conjunctival changes. DESIGN: Interventional case report. METHODS: Case report of a 62-year-old woman with systemic lupus erythematosus (SLE) taking rofecoxib for arthritis for 3 weeks. RESULTS: Stevens-Johnson syndrome after 3 weeks of rofecoxib therapy. CONCLUSION: This case report suggests that oral rofecoxib may trigger Stevens-Johnson syndrome, potentially causing symblepharons, corneal neovascularization and cicatricial ectropions.

Enterotoxigenic Klebsiella pneumoniae in acute childhood diarrhoea.

K. pneumoniae strains recovered as pure or predominant isolate from stool specimens of 50 children below three years of age, presenting with acute watery diarrhoea, were studied for heat-labile enterotoxin production. Twenty three (46%) of the 50 crude toxin concentrates showed positivity in rabbit ileal loops and skin permeability tests. Antigenically 17 (34%) and 20 (40%) of the toxin extracts reacted with immuno-purified anti H-LT antibody in latex particle agglutination and immuno-dot blot assays respectively. Polyacrylamide-gel electrophoresis, Western-blotting and enzyme-immunoassay revealed heat-labile enterotoxin and its subunits in 19 (68%) of 28 extracts tested. In 5 of 10 strains tested the toxigenicity could be transferred to recipient Escherichia coli J-35 in plasmid transfer experiments. Klebsiella induced enterotoxigenic diarrhoea and produced a heat-labile toxin which seems to be biologically, antigenically and possibly genetically related to the heat-labile toxin of the cholera-coli family.

Pre- & post-fumigation bacteriological surveillance of hospital environment.

Study of bacteria in the environment and surfaces of hospital wards revealed Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus faecalis, Acinetobacter species, coagulase negative staphylococci and Serratia marcescens to be the predominant bacterial isolates. Surface sampling following fumigation showed significant reduction in most of the isolates. Bacterial counts in the air also showed considerable decline. Fumigation under proper technical supervision showed significant reduction in bacterial count as compared to that carried out without such supervision. This study highlights that certain bacterial species are predominantly found in the hospital environment and emphasises the need for frequent supervisory monitoring of hospital wards.

Salmonella typhimurium enterotoxin mediated fluid secretion.

Unidirectional Na+ and Cl- fluxes were studied in rats treated with S. typhimurium enterotoxin (S-LT). There was net absorption of Na+ and Cl- in the control group, while in the toxin treated animals there was net secretion of Na+ and Cl- (P less than 0.001). There was no change in the transport of D-glucose in the toxin treated group as compared to the control animals. The Na+, K(+)-ATPase pump was unaltered in the S-LT treated animals (198.67 +/- 11.23 nmoles Pi/mg protein/min) as compared to the control group (189.93 +/- 10.09 nmoles Pi/mg protein/min). There was no change in the unidirectional fluxes of Ca+2 in the S-LT treated animals as compared to the control animals, suggesting no change in the permeability of the S-LT treated intestinal membrane to Ca+2.

Outbreak of Salmonella worthington meningitis & septicaemia in a hospital at Chandigarh (north India).

During August 1988 an outbreak of hospital acquired infection due to S. worthington has been reported at the Nehru Hospital, Postgraduate Institute of Medical Education and Research, Chandigarh. A total of seven neonates presented with the clinical features of meningitis and septicaemia during this outbreak and six babies died. S. worthington was isolated from blood and cerebrospinal fluid respectively. The same strains were isolated from the baby warmer mattress, baby cot, suction machine bottle and wall of the fridge. Samples from doctors, nurses and apparently healthy babies born during this period did not grow the above organism. This appears to be the first report on S. worthington in human beings from India. The outbreak was controlled by thorough cleaning and fumigation. The organisms were also mostly sensitive to antibiotics used, in contrast to the multiple drug resistant pattern reported from elsewhere.

Enterotoxin production & mouse virulence of clinical isolates of Salmonella typhimurium strains.

Twenty five isolates of S. typhimurium from clinical specimens were studied for markers of virulence. Three of five isolates from blood, both isolates from CSF and urine and only two of fifteen isolates from faeces were positive for fluid accumulation in rabbit ileal loop. All these strains produced an enterotoxic principle, antigenically related to cholera coli family of enterotoxins, as detected by latex agglutination and immuno-dot-blot tests. Polymyxin-B treated 6 h cultures yielded the best toxin. All 5 blood isolates, both CSF isolates and one of the two urine isolates showed low LD50 indicating high virulence. The study thus revealed that some strains of S. typhimurium are more virulent and produce more enterotoxins. These strains invade the intestinal mucosa potently and lead to extra-intestinal manifestations. The low virulent strains, on the other hand, are confined to the intestine and cause mild/moderate gastroenteritis. Enzyme assays were done in 5 representative strains of good, moderate and low toxin producers. Catalase and superoxide dismutase assays did not show any correlation with toxin production, thus suggesting that the enzyme production is unlikely to be a reliable indicator of the virulence for S. typhimurium.

Western blot analysis of serological response in Helicobacter pylori in acid peptic diseases.

A prospective study was undertaken in 70 patients presenting with acid peptic disease with the objective of characterising the serological response to Helicobacter pylori and finding antigens specific for the serodiagnosis of H. pylori infection. H. pylori status was assessed by smear microscopy, rapid urease activity, culture and histopathology of endoscopic gastric antral biopsy specimens. Serological characterisation was carried out by using western blotting of various antigenic components of H. pylori and subsequent enzymatic detection of antibodies against them. Four reactive bands in the molecular weight range of 45-65 kDa were present in all subjects irrespective of H. pylori status. Four to six immunoreactive bands in the molecular weight range of 21-45 kDa were found only in patients with positive H. pylori status and histopathologically proven gastritis. These immunoreactive components may be valuable in specific immunodiagnosis of H. pylori infection.

Infection rates in single- and double-lumen central venous catheters in critically ill patients.

BACKGROUND: Catheter-related sepsis is a well known complication in critically ill patients receiving total parenteral nutrition. Micro-organisms may travel from the skin puncture wound along the external surface of the catheter or from the hub through the lumen of the catheter, to be shed into the circulation causing bacteraemia and sepsis. The incidence of sepsis is said to be about three times greater with multiple-lumen catheters than with single-lumen catheters. METHODS: Fifty patients admitted to our intensive care unit were randomly assigned to have either a single-lumen (Group I, 25 patients) or double-lumen (Group II, 25 patients) hydromer-coated, polyurethane central venous catheters of the same gauge and length, placed through the infraclavicular subclavian approach using the Seldinger technique. A sterile dry gauze dressing at the skin puncture site was changed every day. Skin swabs were taken for semi-quantitative culture studies before catheter insertion and removal, from the proximal 3 cm (lying subcutaneously) and distal 5 cm of the catheter segments on removal of the catheter, and venous blood was drawn from a peripheral vein before removal of the catheter. RESULTS: The most common isolate was coagulase negative Staphylococcus. No significant difference was found between the two groups in the incidence of catheter-related infection and catheter-related sepsis. CONCLUSION: Double-lumen central venous catheters placed in critically ill patients do not cause more sepsis than single-lumen catheters.

Effect of blockade of transdiaphragmatic absorption of bacteria on survival in peritonitis: an experimental study in rats.

An experimental rat model of established peritonitis was used to test the effect of intraperitoneal injection of platelet rich plasma (PRP) on blood and peritoneal fluid culture positivity and survival rates. Thirty animals divided into two groups of 15 each were studied. The first group served as control while animals in the second group received intraperitoneal injection of PRP. The use of PRP in established. Peritonitis was of no significant benefit.

Identification of Helicobacter pylori by endoscopic crush cytology.

BACKGROUND: Gastric crush cytology is employed in a variety of situations including diagnosis of malignant disease and the detection of Helicobacter pylori infection. OBJECTIVE: To evaluate the usefulness of gastric crush cytology in the detection of H pylori infection. METHODS: Gastric biopsy specimens from 50 patients of gastric or duodenal peptic ulceration were studied by gastric crush cytology, histopathology, bacteriologic culture and rapid urease test and results of various methods compared. RESULTS: Thirty seven patients had H pylori demonstrable in crush smears and 28 in histopathological sections. In 15 patients, the organism was detected by cytology alone and in 6 samples by histopathology alone. There was concordance of 76% between these two morphological techniques. The organism could be cultured from 22 biopsy specimens and urease test was positive in 37 specimens. CONCLUSION: Gastric crush cytology is a useful method for detection of H pylori infection.

Allergic bronchopulmonary aspergillosis: a retrospective study of 35 cases.

Clinical profile of 35 patients with allergic bronchopulmonary aspergillosis (ABPA) was analysed. The disease was found to be more frequent among females. Constitutional symptoms, expectoration, increased breathless and poor control of asthma were the main presenting features. Skin reactivity against aspergillin and Candida was positive in 30 and 2 cases, respectively. Precipitating antibodies against Aspergillus species was positive in 28 cases, and against Candida albicans in 2 cases. Sputum grew either Aspergillus or C. albicans or both in 19 patients. Absolute eosinophilia was observed only in one third of cases. Chest skiagram revealed characteristic central/proximal bronchiectasis and/or fleeting shadows in all cases. No specific pattern was observed on spirometry. There was no correlation between the duration of bronchial asthma, sputum culture and serology results. Most patients responded well to steroids. One striking feature of the study was that one third of the cases were misdiagnosed as pulmonary tuberculosis and were treated with antitubercular drugs for varying periods of time. A high index of clinical suspicion with appropriate laboratory tests are required to identify these cases.