5-Nitroimidazole refractory giardiasis is common in Matanzas, Cuba and effectively treated by secnidazole plus high-dose mebendazole or quinacrine: a prospective observational cohort study.

OBJECTIVE: To evaluate the effectiveness and tolerability of secnidazole combined with high-dose mebendazole for treatment of 5-nitroimidazole-resistant giardiasis. METHOD: Adults with microscopically verified Giardia intestinalis monoinfection attending a secondary level hospital in Matanzas City, Cuba were prospectively included in a cohort. A recently introduced treatment ladder consisting of metronidazole as first-line treatment, followed by secnidazole, tinidazole, secnidazole plus mebendazole and quinacrine as second-to fifth-line treatments, respectively, was used. Adverse events and treatment success were determined by questioning and microscopy on concentrated stool samples, respectively on days 3, 5 and 7 after the end of treatment. If G. intestinalis was detected on day 3, 5 or 7, then the infection was classified as refractory and no further microscopy was performed. RESULTS: A total of 456 individuals were included. Metronidazole, 500 mg three times daily for 5 days, cured 248/456 (54%) patients. A single 2-g secnidazole dose as second-line treatment cured 50/208 (24%) patients. A single 2-g tinidazole dose as third-line treatment cured 43/158 (27%) patients. Three rounds of 5-nitroimidazole therapy therefore cured 341/456 (75%) patients. Secnidazole plus mebendazole (200 mg every 8 hours for 3 days) cured 100/115 (87%) of nitroimidazole refractory infections. Quinacrine cured the remaining 15 patients. All treatments were well tolerated. CONCLUSIONS: 5-Nitroimidazole refractory giardiasis was common, indicating that an alternative first-line treatment may be needed. Retreatment of metronidazole refractory giardiasis with an alternative 5-nitroimidazole was suboptimal, indicating cross-resistance. Mebendazole plus secnidazole were well tolerated and effective for the treatment of 5-nitroimidazole refractory G. intestinalis infection in this setting.

Quinoline resistance associated polymorphisms in the pfcrt, pfmdr1 and pfmrp genes of Plasmodium falciparum in Iran.

Plasmodium falciparum resistance to chloroquine (CQ) has been documented in Iran since the early 1980s and has since gradually increased. Iran is therefore reviewing its national drug policy for malaria control. We describe the prevalence of single nucleotide polymorphisms (SNP) associated with quinoline drug resistance in south eastern Iran. Pre-treatment blood from patients with uncomplicated but symptomatic P. falciparum infection was analysed. Polymorphisms at codons 76, 152, 163 and 220 of the pfcrt gene (chloroquine resistance transporter) and at codons 86, 184, 1034, 1042 and 1246 of the pfmdr1 gene (multidrug resistance) were determined by PCR-RFLP and sequencing. In addition, SNPs on a recently described multidrug resistance protein (pfmrp) and a microsatellite (MS-4760) in the pfnhe-1 (sodium hydrogen exchanger) gene associated with quinoline and quinine resistance, respectively, were investigated for the first time in field samples not from Thailand. pfcrt 76T was found in 99% and pfmdr1 86Y in 72% of the samples. pfmrp 191H and 437S associated with decreased quinoline response were found to be absolutely linked at a frequency of 13.6%. The pfnhe-1 MS-4760 one repeat allele associated to quinine response in vitro was also detected. Sequencing of the pfcrt 72-76 haplotype revealed that SVMNT was the most common allele as previously observed in India. This suggests that pfcrt found in the Iranian P. falciparum population may have the same origin as in the P. falciparum populations in India but different from that normally found in south east Asia. In conclusion, the frequencies of quinoline resistance associated gene polymorphisms in this region suggest a population that has been significantly selected for by the long use of CQ.

Strain, clone and species: comments on three basic concepts of bacteriology.

Different aspects of the terms strain, clone and species are discussed. The term strain is commonly used to denote a pure culture - here called 'the strain in the taxonomic sense' - but does also refer to a natural concept closely related to the clone. The term clone on the other hand is used both in a general and in a more restricted sense, the latter indicating a low degree of genetic exchange. The important distinction between the definition of a species and the criteria for a species is emphasised and the main kinds of criteria are considered.

Proposed new bacterial taxa and proposed changes of bacterial names published during 1997 and considered to be of interest to medical or veterinary bacteriology.

A list of names of bacteria published or validated in 1997 is presented. Comments are made of the tendency to base names of new taxa on a single bacterial strain and the consequences for reliable descriptions that this tendency implies.

The 1998 list. Proposed new bacterial taxa and proposed changes of bacterial names published during 1998 and considered to be of interest to medical or veterinary bacteriology (an informational note).

A list of names published or validated in 1998 is presented.

The 1997 list. Proposed new bacterial taxa and proposed changes of bacterial names published during 1997 and considered to be of interest to medical or veterinary bacteriology. An informational note.

A list of names published or validated in 1997 is presented. We also comment on the tendency to base names of new taxa on a single bacterial strain, and the consequences for reliable descriptions that this tendency implies.

Metronidazole prophylaxis to prevent infections after total abdominal hysterectomy.

METHODS: In a randomized double-blind study, 134 patients were given 500 mg metronidazole as an intravenous infusion immediately before operation for abdominal total hysterectomy and again 8 hours later and 124 patients received placebo. RESULTS: There was more wound infection, postoperative hospitalization was longer and the sedimentation rate on the sixth postoperative day was significantly higher in the placebo group. There was no difference in postoperative temperature. Postoperative wound infections occurred in 12% in the placebo group and 6% in the metronidazole group. Eight percent in the total material had urinary tract infections, the diagnosis was based on urine cultures. CONCLUSIONS: Prophylaxis with intravenous infusion of metronidazole is recommended in total hysterectomies.

The 1997 list. Proposed new bacterial taxa and proposed changes of bacterial names published during 1997 and considered to be of interest to medical or veterinary bacteriology. An informational note.

A list of names published or validated in 1997 is presented. We also comment on the tendency to base names of new taxa on a single bacterial strain, and the consequences for reliable descriptions that this tendency implies.

The 1997 list. Proposed new bacterial taxa and proposed changes of bacterial names published during 1997 and considered to be of interest to medical or veterinary bacteriology (an informational note).

A list of names published or validated in 1997 is presented. We also comment on the tendency to base names of new taxa on a single bacterial strain, and the consequences for reliable descriptions that this tendency implies.

Unusual Yersinia enterocolitica strains recovered from domestic animals and people in New Zealand.

Twenty five isolates of Yersinia recovered from the faeces of cattle, sheep, goats and people in New Zealand were characterised biochemically and serologically and were found to be unrelated to any known Yersinia species. Two phenotypes were identified biochemically. Testing against all known O-factors of Yersinia showed that the isolates were serologically unique and two new serotypes were proposed, O:77 and O:78. Deoxyribonucleic acid relatedness studies indicated that the strains formed a homogeneous group, closely related to Yersinia enterocolitica. The definitive status of the isolates has not yet been decided.

Comparison of outbreak and nonoutbreak Acinetobacter baumannii strains by genotypic and phenotypic methods.

Thirty-one Acinetobacter baumannii strains, comprising 14 strains from 14 outbreaks in different northwestern European cities and 17 sporadic strains, were compared by investigating various properties of the strains including biotype, antibiogram, cell envelope protein electrophoretic profile, ribotype pattern, and the band pattern generated by a novel genomic fingerprinting method, named AFLP, which is based on the selective amplification of restriction fragments. Results showed that 12 strains from unrelated outbreaks were linked together in two clusters according to their similarities by these typing methods, whereas sporadic strains were more heterogeneous. Outbreak strains appeared to be markedly more resistant to antibiotics than nonoutbreak strains. The uniformity of typing characters in two sets of outbreak strains suggests that strains in each cluster have a common clonal origin.