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N London

Publications and source records attributed to N London.

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In-vivo transfer of resistance plasmids in rat, human or pig-derived intestinal flora using a rat model.

Germ-free rats associated with either rat- (RIF), human- (HIF) or pig-(PIF) derived Enterobacteriaceae-free intestinal flora were used for in vivo experiments to detect transfer of antibiotic resistance. Transfer of resistance was observed most frequently from the porcine donor strain to acceptor strain Escherichia coli K12, showing the highest number of transconjugants in the faeces of HIF-rats. The rats associated with the human donor strain and E. coli K12 as acceptor showed transconjugants less frequently. Only the HIF-rats yielded transconjugants on each sampling day and none at all could be isolated from the PIF-rats. Almost no transconjugants were found in the faeces of rats associated with the pig donor strain and a wild human E. coli strain as acceptor. Factors such as the nature of the donor and recipient strains as well as the origin of the intestinal flora seemed to have an influence on plasmid transfer. Transferability was highest in the HIF-rats and could be increased by administration of lincomycin. This study showed that in vivo transfer of resistance plasmids is possible in rats associated with intestinal floras of different origins. The human intestinal flora seemed to permit better transfer of resistance than that derived from the pig or the rat.

Animals↗

A piperacillin-tazobactam resistant Escherichia coli strain isolated from a faecal sample of a healthy volunteer.

As part of a surveillance programme of the prevalence of antibiotic resistance, the faecal bacteria of healthy people (n = 1348) were examined, and the antibiotic resistance of the Escherichia coli strains determined. One strain out of 142 amoxycillin-resistant isolates, E. coli strain 1662, was also resistant to piperacillin-tazobactam but susceptible to amoxycillin-clavulanic acid. The piperacillin-tazobactam resistance determinant was transferable to standard E. coli strains by conjugation. However, the strain produced a beta-lactamase with several characteristics very similar to those of the TEM-1 beta-lactamase, i.e. pI of 5.4, an M(r) value of 22,000 and a comparable substrate profile. The enzyme was as efficiently inhibited by clavulanic acid and tazobactam as the TEM-1 and TEM-2 beta-lactamases but more than the amoxycillin-clavulanic acid-resistant TRC-1 enzyme. The transferable resistance to piperacillin-tazobactam appears to be mediated by a novel resistance mechanism that has previously not been described.

Anti-Bacterial Agents↗

Resistance in faecal Escherichia coli isolated from pigfarmers and abattoir workers.

Faecal samples collected from three populations of healthy adult volunteers (290 pigfarmers, 316 abattoir workers, 160 (sub)urban residents) living in the south of The Netherlands were analysed for the prevalence and degree of antibiotic resistance of Escherichia coli. Significant differences in prevalence of resistance to amoxicillin, neomycin, oxytetracycline, sulfamethoxazole and trimethoprim were observed. The pigfarmers showed the highest percentages of resistance and the (sub)urban residents the lowest. In contrast no significant differences in high degrees of resistance were observed, except for neomycin. Although both pigfarmers and abattoir workers have regular contact with pigs differences in prevalences of resistance were observed. However, because abattoir workers with intensive and less intensive pig(carcass) contact did not show significant differences, this is probably not the only important source of resistant E. coli in pigfarmers. The high antibiotic use by pigfarmers (5%) and abattoir workers (8%) than by (sub)urban residents (0%) did not result in significantly different resistance percentages.

Abattoirs↗

Effect of antibiotic therapy on the antibiotic resistance of faecal Escherichia coli in patients attending general practitioners.

To analyse the influence of antibiotic therapy on the faecal flora of patients from general practice with complaints of a respiratory tract infection (RTI), 189 paired faecal specimens were collected, before and after completing antibiotic treatment (n = 129) and symptomatic treatment (n = 60). Faecal specimens were examined for the prevalence and degree of resistance to amoxycillin, apramycin, ciprofloxacin, nalidixic acid, neomycin, nitrofurantoin, oxytetracycline, sulphamethoxazole and trimethoprim. In the antibiotic-treated group a significant increase in the prevalence of resistance to amoxycillin post-treatment from 50% to 64% (P < 0.05, Wilcoxon) was observed. In the symptomatic treated group no significant differences in the prevalence of resistance were found. Using discriminant analysis, amoxycillin and doxycycline therapy contributed to an increased prevalence of resistance to amoxycillin and oxytetracycline, respectively. In the antibiotic-treated group Escherichia coli isolates post-treatment had a significantly increased resistance rate to amoxycillin (15%-23%) and to neomycin (2%-6%) (P < 0.05, Wilcoxon). Logistic regression analysis showed a cross resistance to neomycin and kanamycin, and for kanamycin cross-resistance to apramycin, neomycin and streptomycin occurred.

Adolescent↗

Antibiotic resistance of Enterobacteriaceae isolated from the faecal flora of fattening pigs.

From June 1991 to April 1992 407 faecal samples were collected from three groups of pigs (I n = 248, II n = 87, III n = 72) at a pig fattening farm to determine the prevalence and the degree of antibiotic resistance of Enterobacteriaceae as well as the antibiotic susceptibility of the strains isolated. Despite the absence of mass medication during the observation period, the prevalence of resistance to the most commonly used antimicrobial agents in veterinary medicine was high (range amoxicillin 70%-97%, oxytetracycline 89%-100%, sulfamethoxazole 88%-100%, trimethoprim 78%-100%). The high degree of resistance to oxytetracycline and sulfamethoxazole ranged from 8%-67% and 4%-46%, respectively. The percentage of the isolated Escherichia coli strains resistant to oxytetracycline, streptomycin and sulfamethoxazole ranged from 49% to 68%; the other agents tested showed lower percentages (0-13%). Resistance to three or more antibiotics was observed in 43% of the isolates. Of the 52 resistance patterns that could be distinguished, 51% was accounted by only four patterns: oxytetracycline+streptomycin+sulfamethoxazole 20%, sulfamethoxazole 12%, streptomycin+sulfamethoxazole 11% and streptomycin+oxytetracycline 8%.

Animal Husbandry↗

Antibiotic resistance of faecal Enterobacteriaceae isolated from healthy volunteers, a 15-week follow-up study.

From 25 March to 1 July 1991 faecal samples from healthy volunteers of two cities and their rural surroundings, Weert (n = 91) and Roermond (n = 96) were collected weekly and analysed for the presence of Enterobacteriaceae, resistant to ampicillin, ciprofloxacin, nalidixic acid, neomycin, nitrofurantoin, oxytetracycline, sulphamethoxazole or trimethoprim. In total, 682 and 690 samples from Weert and Roermond, respectively, were analysed for the prevalence and the degree of resistance to each antimicrobial agent. The mean prevalence of resistance of the samples from Weert varied from 28% +/- 12 (mean +/- S.D.) for ampicillin to 0.1% +/- 1 (range 0-2%) for ciprofloxacin. For Roermond the prevalence of resistance varied from 41% +/- 7% for sulphamethoxazole to 0% for ciprofloxacin. The high degree of resistance (i.e. > 50% of the faecal flora of one particular individual) varied from 8% +/- 4 for sulphamethoxazole to 2% +/- 2 for trimethoprim for Weert. For Roermond the figures varied from 14% +/- 4 for sulphamethoxazole to 0.3% +/- 1 (range 0-2%) for nalidixic acid. High degrees of resistance were not found for ciprofloxacin and nitrofurantoin in either city. In Weert ampicillin-resistant Enterobacteriaceae were isolated from 69/91 individuals.

Adult↗

Familial Conn's syndrome.

We describe the occurrence of primary hyperaldosteronism in two sisters. Although this is only the second published report of familial Conn's syndrome, it does have implications for the relatives of patients with Conn's syndrome and these are discussed.

Adenoma↗

ERCP findings and the role of endoscopic sphincterotomy in acute gallstone pancreatitis.

A total of 131 patients with acute pancreatitis (of whom 100 had gallstones) underwent endoscopic retrograde cholangiopancreatography (ERCP) during the same hospital admission. Urgent ERCP (less than 72 h) was performed in 68 cases and early ERCP (3-30 days) in 63 cases; 47 had predicted severe attacks and 84 had predicted mild attacks (modified Glasgow criteria). The highest incidence of common bile duct stones occurred in those with predicted severe attacks and those who had urgent ERCP. Highly significant correlations were found between age and common bile duct and pancreatic duct diameters. Significant correlations were also found between the common bile duct and pancreatic duct (correcting for age) and between these and the admission serum bilirubin. The common bile duct diameter was greatest in those with common bile duct stones and predicted severe attacks. A considerably lower incidence of pancreatic duct filling occurred in those with predicted severe attacks and common bile duct stones; in predicted mild attacks the pancreatic duct diameter was greater in those with common bile duct stones. In gallstone patients complications were highest in those with predicted severe attacks but more significantly in those with common bile duct stones. Endoscopic sphincterotomy was undertaken in 37 patients with common bile duct stones without mortality. The overall complication rate in gallstone patients was 19 per cent and the mortality rate was 2 per cent. These findings suggest that common bile duct stones cause acute common bile duct and pancreatic duct obstruction and are closely associated with complications. Urgent ERCP for detection of common bile duct stones, and endoscopic sphincterotomy for treatment, is strongly recommended for patients with predicted severe attacks due to gallstones and should also be considered for others who fail to show clinical improvement.

Acute Disease↗

A prospective study of ERCP and endoscopic sphincterotomy in the diagnosis and treatment of gallstone acute pancreatitis. A rational and safe approach to management.

From a consecutive series of 112 patients with acute pancreatitis, 70 patients with suspected gallstones were randomized to urgent endoscopic retrograde cholangiopancreatography (ERCP) (less than 72 hours) and endoscopic sphincterotomy (ES) if choledochal stones were present (n = 35), or to conventional treatment (n = 35). Endoscopic retrograde cholangiopancreatography, successful in 89% of cases, indicated choledochal stones in 11 patients, all of whom underwent successful stone retrieval by ES. Later during hospital admission, ERCP was performed in 13 more patients and choledochal calculi were extracted from two patients by ES. No complications were attributable to ERCP or ES. Two patients died of biliary pancreatitis; both had been conventionally treated and may have benefited from urgent ERCP/ES. Our experience, which extends to another 24 patients with ERCP and ten with ES during acute pancreatitis, indicates that these are safe techniques and deserve wider consideration in the management of acute pancreatitis.

Acute Disease↗

The role of clinical and biochemical criteria and endoscopic retrograde cholangiopancreatography in the urgent diagnosis of common bile duct stones in acute pancreatitis.

The role of clinical and biochemical criteria in predicting common bile duct (CBD) stones was analyzed in 76 patients with acute pancreatitis undergoing endoscopic retrograde cholangiopancreatography (ERCP) during the same hospital admission. Forty patients had ERCP within 72 hours; cholangiography was successful in 92%. Fifty patients had biliary pancreatitis; 25 patients had CBD stones and all were successfully removed by endoscopic sphincterotomy (ES). Twenty-six patients had nonbiliary pancreatitis. Two patients had complications from ERCP and/or ES; two patients died (no CBD stones) but ERCP was noncontributory. Significant differences were found between the biliary and nonbiliary disease groups with respect to age, and bilirubin. gamma-glutamyl transpeptidase, alkaline phosphatase, alanine transaminase, and amylase levels. The first four factors also discriminated between those patients with and without CBD stones. Logistic discriminant functions were estimated providing probabilities for the presence of CBD stones for each patient but were too cumbersome for clinical use. A simple scoring system was devised on the basis of cut-off levels: bilirubin greater than or equal to 40 mumol/L, gamma-glutamyl transpeptidase greater than or equal to 250 IU/L, alkaline phosphatase greater than or equal to 225 IU/L, and age greater than or equal to 70 years, indicating CBD stones. Bilirubin alone had a sensitivity and specificity of 80%; the specificity increased to 93% with all four factors. These results suggest that clinical and biochemical criteria and ERCP and/or ES may have important roles in the management of patients with suspected biliary pancreatitis.

Acute Disease↗

Pulmonary paragonimiasis in Laotian refugee children.

Three Laotian refugee children with chronic pulmonary complaints and findings were found to have pulmonary paragonimiasis during a one-year period in Chicago. These patients ranged from 8 to 11 years of age and the diagnosis was delayed five to six months in two children because of the unfamiliarity of American physicians with signs and symptoms of this disorder. Clinical manifestations included chronic cough for up to two years, apparent hemoptysis in two patients, lack of fever or sweats, and family history negative for tuberculosis. Physical findings included rales and dullness to percussion, clubbing (one patient), and lack of fever or respiratory distress. All three patients showed interstitial infiltrates on chest roentgenogram whereas two had multiple small cystic areas. Moderate eosinophilia was present. Paragonimus westermani ova were found in stools of two patients, in sputum of two patients, and in bronchoscopic specimens in one patient. All patients demonstrated striking clinical and radiologic improvement following treatment with bithionol (50 mg/kg every other day for 15 doses), which was well tolerated. Lung fluke infestation must be considered in Indochinese refugee children with apparent hemoptysis or chronic pulmonary symptoms, and sputum and stool should be examined for P westermani ova.

Child↗

Carriage of antibiotic-resistant Escherichia coli by healthy volunteers during a 15-week period.

Escherichia coli strains (n = 678 and n = 670) isolated from faecal samples from 90 and 93 healthy volunteers of two cities, Weert and Roermond respectively, were analysed for their susceptibility to 12 antimicrobial agents during a 15-week period. Significant differences between both cities in the distribution of the MIC values were observed for apramycin, chloramphenicol, kanamycin, neomycin, nitrofurantoin, sulfamethoxazole and trimethoprim. For Weert (n = 678) the antibiotic resistance percentages varied from 0.4% for nalidixic acid to 26.7% for sulfamethoxazole. For Roermond (n = 670) the figures varied from 0.6% for nitrofurantoin to 37.5% for sulfamethoxazole. Resistance to amoxicillin/clavulanate was not found in either city. The most frequent pattern was resistance to sulfamethoxazole only, followed by resistance to oxytetracycline, streptomycin and sulfamethoxazole. In each individual there was only a small variation in resistance patterns of the isolates, i.e. the majority had one (n = 51) or two (n = 63) patterns with a maximum of five during the 15-week period. A fully susceptible pattern was found in the strains from 38 individuals.

Carrier State↗

Value of phenotyping methods as an initial screening of Pseudomonas aeruginosa in epidemiologic studies.

When studying the epidemiology of Pseudomonas aeruginosa, determination of the similarity of isolates is crucial. In the present study the distinctive capacity of four phenotyping methods (antibiotic susceptibility patterns, serotyping, phage-typing and outer membrane protein [OMP] profile analysis) was determined and compared to pulsed-field gel electrophoresis (PFGE) of enzyme restricted chromosomal DNA. In all, 91 isolates of P. aeruginosa were cultured from ten patients. Antibiotic susceptibility patterns were concordant for all isolates. Serotyping yielded five, phage-typing eight, OMP profile analysis nine and PFGE seven distinct types of P. aeruginosa. Compared to PFGE, the distinctive capacities were 89% (81/91) for serotyping, 87% (79/91) for phage-typing, and 90% (82/91) for OMP profile analysis. When serotyping results were different, PFGE types also were different (exclusiveness 100%). However, isolates with the same serotype may have various PFGE patterns. In contrast, isolates with similar PFGE patterns could have different phage-types or OMP types. For the study of isolates of P. aeruginosa, serotyping provides a good initial selection to reduce the number of isolates that need to be genotyped.

Bacterial Outer Membrane Proteins↗

The prevalence of antibiotic-resistant faecal Escherichia coli in healthy volunteers in Venezuela.

Faecal samples were collected from healthy volunteers in two regions in Venezuela, the village of Grulla (n = 195) and the city of Mérida (n = 181), and analysed for the prevalence of antibiotic resistant faecal Escherichia coli as well as the antibiotic susceptibility of the strains isolated. The highest prevalences of resistance were observed for amoxicillin, oxytetracycline, sulfamethoxazole and trimethoprim. The percentages found for Grulla were 46, 38, 44 and 30%, respectively; for Mérida 39, 65, 56 and 36%, respectively. In Mérida, a significantly higher prevalence of resistance for oxytetracycline was found (P < 0.05). Significant differences in the distribution of the MIC values between Grulla and Mérida were observed for amoxicillin, chloramphenicol and oxytetracycline (P < 0.05). In Grulla, the most frequent pattern was resistance to amoxicillin only and in Mérida to oxytetracycline only. Amoxicillin resistance was due to production of TEM1 beta-lactamase.

Adolescent↗