Clinical Evaluation of Co-trimoxazole and Furazolidone in Treatment of Shigellosis in Children

Co-trimoxazole (trimethoprim—sulphamethoxazole) was compared with furazolidone in the treatment of shigellosis in two groups of 33 and 30 patients respectively. Those treated with co-trimoxazole recovered more quickly; none had shigellae in the faeces four days after the start of treatment, whereas in the group given furazolidone eight still had positive stool cultures seven days after treatment.The susceptibility of 104 shigella strains to seven antimicrobial agents was studied by plate dilution technique. All agents but tetracycline and chloramphenicol were found highly effective against most of the strains tested. All shigella isolates were resistant to sulphamethoxazole, and 63% were sensitive to trimethoprim. Potentiation of trimethoprim by sulphamethoxazole was shown in that all strains tested became sensitive to the combination of trimethoprim and sulphamethoxazole in a ratio of 1:20.     

Emergence of tetracycline resistance due to a multiple drug resistance plasmid in Vibrio cholerae O139

Abstract Of the 173 clinical strains of Vibrio cholerae O139 isolated from India, Bangladesh, and Thailand tested, six strains from India were resistant to tetracycline, ampicillin, chloramphenicol, kanamycin, and gentamicin. These six strains harbored a self-transmissible plasmid that mediated resistance to tetracycline, ampicillin, chloramphenicol, kanamycin, gentamicin, sulfamethoxazole, trimethoprim, and O/129. The multiple drug resistance plasmids were 200 kb in size and belonged to the incompatibility group C. Although a majority of the O139 strains (94.8%) were highly resistant to streptomycin, sulfamethoxazole, trimethoprim, and O/129, the tetracycline-susceptible strains so far tested were plasmid-negative. The data suggest the existence of two distinct multiple antimicrobial agent resistance (MAR) patterns in V. cholerae O139.     

Increase in antibiotic resistance in Haemophilus influenzae in the United Kingdom since 1977: report of study group.

A survey of antibiotic resistance in Haemophilus influenzae was carried out in the United Kingdom with 25 laboratories participating. The incidence of resistance in the 1841 strains examined was: tetracycline 3.1%, ampicillin 6.2%, chloramphenicol 1.03%, trimethoprim 1.4%, and sulphamethoxazole 1.5%. Of the 115 strains resistant to ampicillin, 106 produced beta-lactamase. Seventy-nine strains were capsulate, none of which was chloramphenicol resistant, but nine produced beta-lactamase (11.4%). Comparison of these figures of antibiotic resistance with those from a similar survey performed in 1977 showed a significant increase in resistance of H influenzae to ampicillin, chloramphenicol, and trimethoprim.     

Resistance of clinical isolates of Haemophilus influenzae in United Kingdom 1986.

Between 1 January and 31 March 1986, 2434 strains of Haemophilus influenzae collected from 23 laboratories in the United Kingdom were examined. With the same criteria as previous studies in 1977 and 1981 the prevalence of resistance was: ampicillin 7.8% (6.2% beta-lactamase producers and 1.6% non-producers), tetracycline 2.7%, chloramphenicol 1.7%, trimethoprim 4.2%, and sulphamethoxazole 3.5%. of the 87 capsulated strains, 15 produced beta-lactamase, nine were resistant to ampicillin but did not produce beta-lactamase, and two strains, one of which produced beta-lactamase, were resistant to chloramphenicol and tetracycline. Since 1977 the prevalence of resistance to ampicillin, chloramphenicol, and trimethoprim has increased significantly. During 1981-6 strains resistant to ampicillin but not producing beta-lactamase and strains resistant to trimethoprim have significantly increased.     

Susceptibility to selected antibiotics of Yersinia enterocolitica 03 strains, carrying and not carrying plasmid pYV

A total of 199 clinical strains of Yersinia enterocolitica serotype O3, biotype 4 were tested for their susceptibility to antibiotics (158 strains carried the virulence plasmid pYV and 41 strains did not). 114 isolates were tested by standard disk diffusion method for 21 antibiotics. Almost all tested strains were resistant to ampicillin and cefazolin and susceptible to amoxycillin/clavulanate, cefaclor, cefamandole, cefuroxime, cefotaxime, ceftriaxone, aztreonam, imipenem, gentamicin, amikacin, netilmicin, tetracycline, doxycycline, chloramphenicol, ciprofloxacin, sulphamethoxazole, co-trimoxazole, trimethoprim and furazolidone. In addition minimal inhibitory concentrations (MICs) of 15 antibiotics were determined by agar dilution method for all 199 strains (158 plasmid positive and 41 strains plasmid negative). Third-generation cephalosporins such as cefotaxime and ceftriaxone and a fluoroquinolone (ciprofloxacin) were the most active antimicrobial agents, tested followed by aztreonam, imipenem, trimethoprim, tetracycline, gentamicin, chloramphenicol, amoxycillin/clavulanate, cefaclor, cefuroxime, amikacin, furazolidone and sulphamethoxazole. The present study demonstrated a high susceptibility of clinical strains of Y. enterocolitica to most of the tested antibiotics. In general, there was no significant difference between susceptibility of virulence plasmid pYV positive and virulence plasmid negative strains to antibacterial agents.     

Drug resistance in Vibrio cholerae strains isolated from clinical specimens

Cholera is a serious epidemic and endemic disease caused by the Gram-negative bacterium Vibrio cholerae. SXT is an integrative conjugation element (ICE) that was isolated from a V. cholerae; it encodes resistance to the antibiotics chloramphenicol, streptomycin and sulfamethoxazole/trimethoprim. One hundred seven V. cholerae O1 strains were collected from cholera patients in Iran from 2005 to 2007 in order to study the presence of SXT constin and antibiotic resistance.The study examined 107 Vibrio cholerae strains isolated from cholera prevalent in some Iranian provinces. Bacterial isolation and identification were carried out according to standard bacteriological methods. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) to four antibiotics (chloramphenicol, streptomycin, sulfamethoxazole, and trimethoprim) were determined by broth microdilution method. PCR was employed to evaluate the presence of established antibiotic resistance genes and SXT constin using specific primer sets.The resistance of the clinical isolates to sulfamethoxazole, trimethoprime, chloramphenicol, and streptomycin was 97%, 99%, 99%, and 90%, respectively. The data obtained by PCR assay showed that the genes sulII, dfrA1, floR, strB, and sxt element were present in 95.3%, 95.3%, 81.3%, 95.3%, and 95.3% of the V. cholerae isolates.The Vibrio strains showed the typical multidrug-resistance phenotype of an SXT constin. They were resistant to sulfamethoxazole, trimethoprime, chloramphenicol, and streptomycin. The detected antibiotic resistance genes included dfrA for trimethoprim and floR, strB, sulII and int, respectively, for chloramphenicol, streptomycin, sulfamethoxazole, as well as the SXT element.     

Sensitivity of Haemophilus influenzae to Antibiotics

The use of many different antibiotics to treat chest infection has led us to test the sensitivity of 68 strains of Haemophilus influenzae to 15 different compounds. These included established compounds such as ampicillin and tetracycline and newer agents such as cephalosporins and clindamycin. The minimum inhibitory concentrations of the compounds for H. influenzae were then compared with blood levels attained after the usual dose regimens. There has been a significant increase in tetracycline resistance in the last few years, but all strains were sensitive to ampicillin, chloramphenicol, sulphamethoxazole, and trimethoprim, Several antibiotics were found to be microbiologically unsuitable for treating H. influenzae infections.     

Incidence of resistance to ampicillin,chloramphenicol, kanamycin and tetracycline amongSalmonella species isolated in The Netherlands in 1972, 1973 and 1974

The resistance ofSalmonellae to drugs has been studied in the Netherlands since 1958. In 1972, 1973, and 1974 respectively, 14241, 13086, and 22927 strains were tested for resistance to ampicillin, chloramphenicol, kanamyci and tetracycline. From 1973 all strains were also tested for resistance to trimethoprim. In the period covered, the yearly incidence of resistance to at least one of the above drugs ranged from 39.2% to 45.6% of all strains obtained from various sources (humans, animals, animal products, sewage, etc.). A new finding in the period 1972 to 1974 was that many multiply resistant strains emerged inS. typhimurium and inS. dublin isolated from calves and cattle. In 1974, 64.4% of all strains ofS. typhimurium from these animals appeared to be resistant to ampicillin, tetracycline, chloramphenicol and kanamycin, and 25.5% of those ofS. dublin were found to be resistant to chloramphenicol and tetracycline. Of all strains ofSalmonellae examined in 1973 and 1974 respectively, 0.15 and 0.22% were resistant to trimethoprim, the main component of the twin-drug cotrimoxazol. Of the 142 strains ofS. typhi isolated in 1972 to 1974 two were resistant to tetracycline only, and one was resistant to all four antibiotics. The others had a normal susceptibility pattern.     

Characterization of a clinical Vibrio cholerae O139 isolate from Mexico

Pathogenic strains of Vibrio cholerae O139 possess the cholera toxin A subunit (ctxA) gene as well as the gene for toxin co-regulated pili (tcpA). We report the isolation of a ctxA-negative, tcpA-negative V. cholerae O139 strain (INDREI) from a patient in Mexico diagnosed with gastrointestinal illness. Certain phenotypic characteristics of this strain were identical to those of V. cholerae O1 biotype El Tor. Unlike ctxA-positive V. cholerae O139 strains, this strain was sensitive to a wide panel of antibiotics, including ampicillin, chloramphenicol, ciprofloxacin, gentamicin, furazolidone, nalidixic acid, nitrofurantoin, tetracycline, trimethoprim-sulfamethoxazole, and streptomycin, but was resistant to polymyxin B. Ribotype and pulsed-field gel electrophoresis profiles of INDRE1 differed from those of ctxA-positive V. cholerae O139 and other V. cholerae strains. Phenotypic characteristics of the Mexico strain were similar to those reported for V. cholerae O139 isolates from Argentina and Sri Lanka.     

Effects of antibiotics on the growth and morphology of Pasteurella multocida.

The effects of subminimal inhibitory concentrations (subMICs) of certain antibiotics, namely penicillin G, tetracycline and trimethoprim/sulphamethoxazole, on the growth and morphology of Pasteurella multocida were evaluated. SubMICs of penicillin markedly reduced the growth of P. multocida. Tetracycline and trimethoprim/sulphamethoxazole had no effect on its growth. SubMICs of penicillin greatly affected the morphology of P. multocida. At the highest concentrations tested (1/2 and 1/4 MIC) cells were acapsulate, and long filamentous cells (4-6 microns) were observed with some isolates. There was no correlation between the observed differences in the penicillin-binding proteins of the P. multocida isolates, and the extent of cell filamentation induced by penicillin G. SubMICs of tetracycline and trimethoprim/sulphamethoxazole did not seem to affect capsule production although filamentation was observed. Our results indicate that subMICs of penicillin can reduce growth of P. multocida. Furthermore, results also indicate that subMICs of antibiotics can affect the production of capsular material and the morphology of P. multocida.     

Experimental resistance of Vibrio cholerae el tor to nalidixic acid and fluoroquinolones]

It was shown that sensitivity of Vibrio cholerae eltor P-5879 to tetracycline, levomycetin, furazolidone, trimethoprim/sulfamethoxazole, aminoglycosides, beta-lactams, rifampicin, quinolones in vitro correlated with drugs efficacy in the treatment of experimental cholera of albino mice. Mutants of V. cholerae eltor P-5879 Nalr resistant to nalidixic acid (MIC 160-200 mg/l) formed with frequency 10(-9)-110(-8) had no cross resistance to fluoroquinolones. But the efficacy of ofloxacin, lomefloxacin, norfloxacin against these mutants in vivo reduced, though it was not changed in vitro. Mutants of V. cholerae eltor P-5879 resistant to fluoroquinolones and selected after culturing in the presence of the drugs had cross resistance to all quinolones studied. Infection caused by Cpfr mutant could not be treated with nalidixic acid and fluoroquinolones, therapeutic efficacy of rifampicin and beta-lactams, also reduced though sensitivity in vitro was not changed. The results of investigation proves the necessity of quinolones use for cholerae treatment as it is recommended for other severe enteric infections.     

Isolation of Salmonella Enteritidis phage type 21b from a Eurasian eagle-owl (Bubo bubo)

A case of fatal salmonellosis in a Eurasian eagle-owl (Bubo bubo) from Bursa Province (northwestern Turkey) is described. The organs of the bird were examined histopathologically and microbiologically. Macroscopic and microscopic findings were consistent with a Salmonella infection. Salmonella enterica subspecies enterica serovar Enteritidis (S. Enteritidis) phage type (PT) 21b was isolated from the liver and spleen in pure culture and from the intestine. The isolate was susceptible to amoxycillin/clavulanic acid, ampicillin, chloramphenicol, gentamicin, kanamycin, tetracycline, and trimethoprim/sulphamethoxazole. This is the first report of an isolation of salmonellae from a wild bird species from Turkey and the first time S. Enteritidis PT21b has been reported from Turkey.     

Difference of Phenotype and Genotype Between Human and Environmental: Isolated Vibrio cholerae in Surabaya,Indonesia

Cholera due to Vibrio cholerae has been spreading worldwide, although the reports focusing on Indonesian V. cholerae are few. In this study, in order to investigate how V. cholerae transmitted to human from environment. We extended an epidemiological report that had investigated the genotype of V. cholerae isolated from human pediatric samples and environmental samples. We examined 44 strains of V. cholerae isolated from pediatric diarrhea patients and the environment such as shrimps or oysters collected in three adjacent towns in Surabaya, Indonesia. Susceptibilities were examined for 11 antibiotics. Serotype O1 or O139 genes and pathogenic genes including cholera toxin were detected. Multi-locus sequence typing (MLST) and enterobacterial repetitive intergenic consensus (ERIC)-PCR were also performed to determine genetic diversity of those isolates. Serotype O1 was seen in 17 strains (38.6%) with all pathogenic genes among 44 isolates. Other isolates were non-O1/non-O139 V. cholerae. Regarding antibiotic susceptibilities, those isolates from environmental samples showed resistance to ampicillin (11.4%), streptomycin (9.1%) and nalidixic acid (2.3%) but those isolates from pediatric stools showed no resistance to those 3 kinds of antibiotics. MLST revealed sequence type (ST) 69 in 17 strains (38.6%), ST198 in 3 strains (6.8%) and non-types in 24 strains (54.5%). All the ST69 strains were classified to O1 type with more than 95% similarity by ERIC-PCR, including all 6 (13.6%) isolates from environmental samples with resistance to streptomycin. In conclusion, V. cholerae O1 ST69 strains has been clonally spreading in Surabaya, exhibiting pathogenic factors and antibiotic resistance to streptomycin, especially in the isolates from environment.     

Isolation of a new drug-resistance plasmid from a strain of Vibrio parahaemolyticus

A new R plasmid, pSA55, with a molecular weight of 112 megadaltons (Md), was isolated from a strain of Vibrio parahaemolyticus with multiple drug resistance. The pSA55 plasmid conferred on its host resistance to chloramphenicol, tetracycline, streptomycin, kanamycin, ampicillin, trimethoprim and 2,4-diamino-6,7-diisopropyl pteridine, and belongs to incompatibility group C. The plasmid was transferable to Escherichia coli, V. parahaemolyticus, V. alginolyticus and NAG bivrio at a frequency of 10(-3) approximately -7, and was stably inherited by the transconjugants of these species. The conjugal transfer of pSA55 plasmid was significantly affected by the growth culture phase. The resistance pattern and resistance levels of transconjugants were the same as those of the donor strain. We did not observe fluctuations in minimal inhibitory concentrations with transfer, unlike the case of V. cholerae. The relationship between the pSA55 plasmid and the Kanagawa phenomenon was not clarified in the present study.     

Trimethoprim and Sulphamethoxazole in Typhoid

Six patients with proved typhoid fever were treated with a combination of trimethoprim and sulphamethoxazole; four others were treated with chloramphenicol. All ten patients made an uneventful recovery.Though the numbers are small it appears that the patients treated with the combined drugs did just as well as those treated with chloramphenicol, and fever seemed to subside quicker with the combined drugs.Trimethoprim and sulphamethoxazole have low toxicities, so further studies of their use in the treatment of typhoid are justified.     

Antibiotic resistance of Salmonella strains isolated from children living in the wastewater-spreading field of Marrakesh city (Morocco)

A total of 813 Salmonella strains isolated from raw wastewater and stool specimens of inpatient children, living in the wastewater-spreading field of Marrakesh city, were examined for their susceptibility to 15 antimicrobial agents. All the isolates were susceptible to cefotaxime, and almost of them showed susceptibility to gentamicin (99.88%), trimethoprim-sulphamethoxazole (98.04%), nalidixic acid (98.04%), kanamycin (97.30%), trimethoprim (97.18%), and chloramphenicol (96.07%). The highest levels of antibiotic resistance were obtained for cephalothin (29.27%), amoxicillin (26.44%), sulphamethoxazole (26.07%), and ampicillin (25.21%). The strains from the serogroup B showed the highest antibiotic resistance frequencies. The percentage of polyresistant strains (36.09%) was significantly higher than that of monoresistant isolates (15.49%). The incidence of drug resistance in Salmonella isolates from stools was significantly higher than in those isolated from wastewater.     

Site-specific integration of the conjugal Vibrio cholerae SXT element into prfC

Vibrio cholerae O139, the first non-O1 serogroup of V. cholerae to give rise to epidemic cholera, is characteristically resistant to the antibiotics sulphamethoxazole, trimethoprim, chloramphenicol and streptomycin. Resistances to these antibiotics are encoded by a 62 kb self-transmissible, conjugative, chromosomally integrating element designated the 'SXT element'. We found that the SXT element integrates site specifically into both V. cholerae and Escherichia coli K-12 into the 5' end of prfC , the gene encoding peptide chain release factor 3. Integration of the SXT element interrupts the chromosomal prfC gene, but the element encodes a new 5' end of prfC that restores the reading frame of this gene. The recombinant prfC allele created upon element integration is functional. The integration and excision mechanism of the SXT element shares many features with site-specific recombination found in lambdoid phages. First, like λ, the SXT element forms a circular extrachromosomal intermediate through specific recombination of the left and right ends of the integrated element. Second, chromosomal integration of the element occurs via site-specific recombination in a 17 bp sequence found in the circular form of the SXT element and a similar 17 bp sequence in prfC . Third, both chromosomal integration and excision of the SXT element were found to require an element-encoded int gene with strong similarities to the λ integrase family. Based on the properties of the SXT element, we propose to classify this element as a CONSTIN, an acronym for a conjugative, self-transmissible, integrating element.     

Value of stool examination in patients with diarrhoea.

Findings of stool examinations in 1593 patients with diarrhoea due to a single enteric pathogen--enterotoxigenic Escherichia coli rotavirus, Shigella, Campylobacter jejuni, Vibrio cholerae 0:1, Entamoeba histolytica, or Giardia lamblia--were reviewed to determine how well they predicted the agent associated with the diarrhoea. Specimens were examined visually for blood and mucus, tested for pH, and examined under a microscope for the presence of red and white blood cells, parasites, and stool fat. Although visible blood was more common in specimens from patients infected with Shigella (51%) and Ent histolytica (39%) than in those from patients infected with other agents (6%; p less than 0.01), patients infected with Shigella were most likely to have numerous faecal leucocytes (greater than 50/high power field: 39% v 8% of all patients and 7% of patients infected with Ent histolytica, p less than 0.01 in both cases). Patients infected with enterotoxigenic E coli, rotavirus, V cholerae 0:1, or C jejuni had loose stools with fewer red or white cells. Patients infected with rotavirus and C jejuni were more likely to have acid stools with 3 to 4+ fat, but these findings were related to young age and breast feeding. Stool examination is most useful in establishing a diagnosis of dysentery and in helping to distinguish between patients infected with Shigella and Ent histolytica; it is of limited usefulness in discriminating between pathogens causing watery diarrhoea.     

Trimethoprim in the Treatment of Urinary Infections in Hospital

Success in the cure of urinary infections of hospital patients was compared for five-day courses of sulphamethoxazole alone, sulphamethoxazole plus one-tenth its weight of trimethoprim, and sulphamethoxazole plus one-fifth its weight of trimethoprim (Septrin). The cure rates were 65%, 84%, and 92% respectively. Fifty-four per cent. of 111 patients had urinary tract abnormalities. Forty-three per cent. of the causative organisms were sulphonamide-resistant in vitro. There were no major side-effects, though two patients had pruritus or a rash.The degree of potentiation of sulphamethoxazole activity by one-fifth the weight of trimethoprim was so great that its cure rate of infections due to sulphonamide-resistant organisms exceeded that of sulphamethoxazole alone used in infections due to sulphonamide-sensitive organisms. The degree of synergism between trimethoprim and sulphamethoxazole demonstrated in vitro against urinary organisms was directly related to the cure rate of the combination.     

A new type of conjugative transposon encodes resistance to sulfamethoxazole, trimethoprim, and streptomycin in Vibrio cholerae O139.

Vibrio cholerae O139 is the first non-O1 serogroup of V. cholerae to give rise to epidemic cholera. Apparently, this new serogroup arose from an El Tor O1 strain of V cholerae, but V. cholerae O139 is distinguishable from V. cholerae El Tor O1 by virtue of its novel antigenic structure and also its characteristic pattern of resistances to the antibiotics sulfamethoxazole, trimethoprim, streptomycin, and furazolidone. We found that the first three of these antibiotic resistances are carried on an approximately 62-kb self-transmissible, chromosomally integrating genetic element which we have termed the SXT element. This novel conjugative transposon-like element could be conjugally transferred from V. cholerae O139 to V cholerae O1 and Escherichia coli strains, where it integrated into the recipient chromosomes in a site-specific manner independent of recA. To study the potential virulence properties of the SXT element as well as to improve upon the live attenuated O139 vaccine strain Bengal-2, a large internal deletion in the SXT element was crossed on to the Bengal-2 chromosome. The resulting strain, Bengal-2.SXT(s), is sensitive to sulfamethoxazole and trimethoprim and colonizes the intestines of suckling mice as well as wild-type strains do, suggesting that the SXT element does not encode a colonization factor. Derivatives of Bengal-2.SXT(s) are predicted to be safe, antibiotic-sensitive, live attenuated vaccines for cholera due to the O139 serogroup.