Uptake pathways of clinical isolates of Proteus mirabilis into human epithelial cell lines

Proteus mirabilis isolates obtained from urine and faeces showed high invasion levels into several human epithelial cell lines in gentamicin assays. Invasion efficiencies of isolate 102 from a monkey with diarrhoea equalled or even exceeded those of Salmonella typhi strain Ty2 (6.3 to 13.8% of the inoculum). Vegetative, non-swarming P.mirabilis invaded epithelial cells efficiently and were found in endosomes and free in the cytoplasm. Although inhibition of eukaryotic protein synthesis by cycloheximide did not reduce bacterial uptake, inhibition with bacteriostatic antibiotics of bacterial protein-, RNA-, or DNA-synthesis reduced invasion drastically. Involvement of eukaryotic structures and processes in internalization was determined by using various inhibitors in the invasion assay. Uptake of P.mirabilis isolated from urine into gut (INT 407, HCT-8) cells and bladder (T24) cells was dramatically inhibited only by microfilament depolymerization. Internalization of faecal isolate 102 into gut or bladder epithelial cells was inhibited by depolymerization of microfilaments or microtubules. Engulfment of isolate 102 into T24 bladder cells was also reduced by inhibition of receptor-mediated endocytosis. Interference with endosome acidification decreased the number of intracellular bacteria of isolate 102 in all three cell lines. These results suggest that P.mirabilis isolates from different sources are internalized by epithelial cells by different eukaryotic processes, and that these processes can vary between cell lines.

Testing of susceptibility of Mycobacterium tuberculosis to isoniazid and rifampin by mycobacterium growth indicator tube method

We tested isolates of Mycobacterium tuberculosis recovered from 117 patients for their susceptibilities to isoniazid (INH) and rifampin (RIF) by the Centers for Disease Control and Prevention's disk modification of the indirect method of proportions (MOP) test and a three-tube mycobacteria growth indicator tube (MGIT; BBL) antimycobacterial susceptibility test (AST). Sixty-seven of the M. tuberculosis isolates were recovered from Lowenstein-Jensen (BBL) subcultures, and 50 of the isolates were recovered from MGIT cultures of samples from various body sites. For the MGIT AST method, 0.5 ml of test organism suspension was inoculated into an MGIT with 0.1 micrograms of INH per ml, an MGIT with 1.0 micrograms of RIF per ml, and growth control MGIT. The tubes were incubated at 37 degrees C and were examined daily. The MGIT AST results were interpreted as follows: susceptible if the tubes containing INH or RIF did not fluoresce within 2 days of the time that the positive growth control fluoresced and resistant if the tubes containing INH or RIF did fluoresce within 2 days of the time that the positive growth control fluoresced. The mean time fluorescence for the positive growth control was 5.5 days. The two methods were in agreement for 114 of the 117 isolates from patients, while for 3 isolates there were minor discordant results.

Effect of rifampin on the plasma concentration and the clinical effect of haloperidol concomitantly administered to schizophrenic patients

We assessed the changes of plasma haloperidol concentrations and clinical responses repeatedly up to 4 weeks after coadministration or discontinuation of rifampin in 12 schizophrenic patients taking haloperidol alone (group I) and 5 patients taking haloperidol and antituberculotic drugs (group II). After coadministration of rifampin in group I, daily trough haloperidol concentrations rapidly decreased and reached 63% of baseline level by day 3, 41.3% by day 7, and 30% by day 28. On the other hand, after discontinuation of rifampin in group II, plasma haloperidol concentration increased to 140.7% of baseline level by day 3, 228.7% by day 7, and 329% by day 28. In this study, a 30% or greater change in the clinical rating scale was considered a positive clinical response of the drug interaction. Using this criterion, 50% of the group I subjects responded according to the Brief Psychiatric Rating Scale (BPRS) total score, and 25% responded according to the BPRS subscale for psychiatric symptoms. No positive responses were observed in group II patients. These results strongly suggest that rifampin interacts with the clinical effects as well as the plasma concentrations of coadministered haloperidol, and careful monitoring should be considered when coadministration or discontinuation of rifampin is needed in a schizophrenic patient taking haloperidol.

Bacteriostatic and bactericidal activities of benzoxazinorifamycin KRM-1648 against Mycobacterium tuberculosis and Mycobacterium avium in human macrophages

Inhibitory and bactericidal activities of KRM-1648 were determined against Mycobacterium tuberculosis and M. avium residing in human monocyte-derived macrophages and extracellular M. tuberculosis and M. avium. MICs and MBCs of KRM-1648 against intracellular and extracellular bacteria were substantially lower than those of rifampin. The MICs and MBCs of either drug against the intracellular bacteria were only twofold lower than or equal to the values found for extracellular bacteria. The prolonged effect of KRM-1648 found in this study is probably associated with high ratios of intracellular accumulation, which were 50- to 100-fold higher than that found for rifampin. Further studies on intracellular distribution of KRM-1648 and on the sites of actual interaction between the drug and bacteria residing in macrophages are necessary, as well as evaluation of combined effects of KRM-1648 with other drugs in long-term macrophage culture experiments.

Semipreparative chromatographic separation of cyclosporin G metabolites generated by microsomes from rabbits treated with rifampicin

An efficient drug-induced rabbit liver microsomal enzyme system, that may be easily scaled up, has been applied to produce milligram (mg) quantities of cyclosporin G metabolites (CMs). Using hepatic microsomal preparations from rabbits pretreated with rifampicin (RIF) and a NADPH regenerating system, we converted 60% of the cyclosporin G (CsG) to 12 CMs in 2 hr. CMs were recovered by solid-phase extraction. Separations performed on a semipreparative scale with two sequential 250 x 10 mm reversed-phase HPLC columns yielded mg quantities of CMs. The yield of GM1 and GM9 obtained by a single HPLC separation step was estimated to be 1585 +/- 103 micrograms and 648 +/- 33 micrograms, respectively. Other CMs produced by this microsomal enzyme system were GM19, GM4N, GM1c, the aldehydic isomers (GM1cAL and GM1AL), GM14N, GM4N9, GM1A, and GM1cA. The purity of CMs was confirmed by analytical HPLC and their molecular weights (M.W.) were determined by Fast Atomic Bombardment Mass Spectrometry (FABMS). Biotransformation of CsG and cyclosporine (CsA) was also compared using this in vitro model system. Significant difference was found between the rate of aldehydic metabolite formation from CsG and that from CsA. This translates to a faster rate of AM1cAL and AM1AL formation than that of GM1cAL and GM1AL. In addition, the rate of CsG conversion to GM9 appears to be faster than that of CsA conversion to AM9.

Stimulation of bile acid 6 alpha-hydroxylation by rifampin

BACKGROUND

Rifampin was shown to relieve pruritus in cholestatic liver diseases. There has been much speculation about the origin of pruritus, but it has not yet been comprehensively explained. The role of bile acids in producing pruritus is obscure and still under debate. Since rifampin both inhibits the uptake of bile acids into the hepatocyte and strongly induces mixed-function oxidases in the liver, the beneficial effects of this drug might be a consequence of altered bile acid metabolism.

METHODS

We investigated the influence of rifampin on urinary bile acid excretion with special respect to glucuronide and sulphate conjugates in 14 healthy volunteers before and after administration of rifampin, 600 mg x 7 days, using each subject as his or her own control.

RESULTS

Bile acid glucuronide excretion increased from 0.55 to 1.19 mumol/24 h. This was in particular due to a significant increase of the urinary excretion of the 6 alpha-hydroxylated hyocholic and hyodeoxycholic acids, the relative amounts of which accounted for about two thirds of the urinary bile acid excretion. Excretion of sulphates, however, decreased from 1.40 to 0.86 mumol/24 h due to a significantly reduced excretion of lithocholic acid sulphate. No changes in the excretion rates of other primary and secondary bile acids and no changes in their conjugation patterns were observed.

CONCLUSIONS

The results provide evidence that rifampin induces 6 alpha-hydroxylation of bile acids. The products are subsequently glucuronidated at the 6 alpha-hydroxy group, thus stimulating renal excretion of potentially toxic bile acids.

Inducing properties of rifampicin and rifabutin for selected enzyme activities of the cytochrome P-450 and UDP-glucuronosyltransferase superfamilies in female rat liver

Important species differences have been reported concerning the induction properties of rifampicin towards enzymes of the P-450 superfamily. Mice, rabbits and humans are far more responsive than rats and guinea pigs. In the present study a strong induction of cytochrome P-450 3A-dependent enzyme activities was observed in female rat liver microsomes after high dose treatment (> or = 250 mg/kg/day for 9 days) with rifampicin, resulting in an up to 30-fold enhanced hydroxylation rate of testosterone in the 2 beta-, 6 beta- and 15 beta-position in vitro. Other cytochrome P-450 isozyme-selective reactions were not, or only marginally, affected. A steep increase in cytochrome P-450 3A activity on a moderate elevation of the dose administered, together with the previously observed lack of efficient induction with doses below 200 mg/kg/day demonstrated that there is a threshold in enzyme induction by rifampicin. For rifabutin such a threshold was not apparent. Induction by rifabutin showed an isoenzyme-selectivity profile similar to that produced by rifampicin, but the maximally achievable induction of cytochrome P-450 3A by rifabutin was about two-fold lower compared with rifampicin. Rifampicin and rifabutin enhanced the glucuronidation of 1-naphthol, 4-hydroxybiphenyl and beta-estradiol by a factor of two to three. The potential implications of the enzyme induction by rifampicin derivatives in terms of possible drug-drug interactions are discussed.

New drug susceptibility test for Mycobacterium tuberculosis using the hybridization protection assay

We developed a novel method for early detection of drug-resistant strains of Mycobacterium tuberculosis by using the hybridization protection assay (HPA). The number of viable bacteria during the incubation period correlated well with the number of relative light units measured by the HPA. In addition, the relative light unit values of susceptible strains on the first, third and fifth days of incubation were significantly different from those of resistant strains for both isoniazid and rifampin. Our results suggest that after isolation of the organism from clinical specimens, drug-resistant strains of M. tuberculosis are accurately detected by the HPA even after 1 day of incubation with the drug.

The effect of rifampicin on adaptive resistance of Pseudomonas aeruginosa to aminoglycosides

Using the dynamic chequerboard technique, we confirmed that rifampicin produces a synergistic bactericidal effect when combined with amikacin or netilmicin. Adaptive resistance was suppressed when rifampicin was added to aminoglycoside after, but not during, first exposure to amikacin or netilmicin. The effect of rifampicin on adaptive resistance could account for the synergy between rifampicin and aminoglycosides.

Characterization of streptomycin resistance mechanisms among Mycobacterium tuberculosis isolates from patients in New York City

From a collection of 367 isolates of Mycobacterium tuberculosis from patients in New York City in 1994, 45 isolates (12.3%) were resistant in vitro to 2 micrograms or more of streptomycin (SM) per ml. We further evaluated these isolates for levels of SM resistance and for mutations previously associated with resistance in the rpsL (S12 ribosomal protein) gene and the rrs (16S rRNA)-coding region. Twenty-four isolates, representing nine distinct patterns of susceptibility to antituberculosis drugs, were resistant to 500 micrograms of SM per ml and shared a common point mutation at nucleotide 128 in the rpsL gene. This mutation, which substitutes lysine for arginine in the S12 ribosomal binding protein, was not present in isolates with low-level SM resistance or in SM-susceptible control isolates. Among 20 isolates with low-level SM resistance, one possessed a substitution (C-->G865) in the 912 loop of the rrs gene. No mutations in the 530 loop of the rrs coding region were detected, suggesting the presence of an alternative SM resistance mechanism in 19 isolates. Single-strand conformation polymorphisms of mutants were readily detected by a nonradioactive gel screen.

An entomopoxvirus homologue of the vaccinia virus D13L-encoded 'rifampicin resistance' protein

The Heliothis armigera entomopoxvirus (HaEPV) genome encodes a predicted 68 kDa polypeptide related to the 'rifampicin resistance' protein of vaccinia virus (with 30 % identity), and an homologous swinepox virus protein (27% identity). We were unable to isolate an HaEPV genotypic variant encoding a predicted C-terminal truncated form of the protein, suggesting that the C terminus of the molecule may be essential to protein function, and, in turn, that this function may be essential to viral replication. HaEPV replication was substantially reduced in host cells exposed to rifampicin, but the observed cytotoxic properties of the drug made it impossible to determine the specific cause of that inhibition. We suggest that possession of a gene encoding a member of this polypeptide family might represent a defining molecular characteristic of the Poxviridae.

[Lung diseases due to opportunistic environmental Mycobacteria in patients uninfected with human immunodeficiency virus. Risk factors, clinical and diagnostic aspects and course]

Diseases caused by opportunistic ambient mycobacteria (OAM) are common in HIV-positive patients, although they also occur in immunocompetent individuals. The objective of the present study was to describe the risk factors, clinical signs, course and microbiological spectrum of OAM that cause pulmonary diseases in non HIV-infected individuals in our community. We reviewed 29 consecutive patients with OAM-caused pulmonary disease between 1989-1994 (26 men and 3 women, mean age 58 +/- 14 years). Infections were by Mycobacterium kansasii, 19 (66%) cases; M. avium complex, 7 (24%) cases; M. chelonei, 2 (7%) cases, and M. flavescens, one (3%) case. Risk factors most often associated to infection were smoking and a history of pulmonary disease (chronic obstructive pulmonary disease or residual tuberculosis). Clinical signs were non specific, although toxic syndrome and unproductive cough predominated. Chest films were indistinguishable from those for infection by M. tuberculosis, with cavitated alveolar fibrosis being the main pattern. In vitro drug sensitivity tests showed that all strains were resistant to isoniazid, and that M. avium complex and M. chelonei strains were resistant to rifampicin, streptomycin and, to a lesser degree, to ethambutol. With prolonged medical treatment lasting from 12 to 24 months with first line drugs, outcome was good for the 17 patients for whom full follow-up information was available. Therapy failed to eradicate the bacteria in only 2 patients.

Insusceptibility of members of the class Mollicutes to rifampin: studies of the Spiroplasma citri RNA polymerase beta-subunit gene

In order to study the mechanism of insusceptibility of Spiroplasma citri to rifampin, we have cloned and sequenced its rpoB gene, which encodes the beta subunit of RNA polymerase. By comparison of the deduced amino acid sequence with sequences of beta subunits from susceptible and resistant bacteria, it was possible to identify several differences in the so-called Rif region (encompassing rpoB codons 500 to 575 in the Escherichia coli sequence). We constructed a chimeric rpoB gene made of the E. coli rpoB gene in which the Rif region was replaced by the equivalent region from S. citri. E. coli cells harboring this chimeric gene were resistant to rifampin. Subsequent experiments involving site-directed mutagenesis demonstrated that a single amino acid substitution (asparagine at position 526) was able to provide high-level rifampin resistance in E. coli.

Characterization of rpsL and rrs mutations in streptomycin-resistant Mycobacterium tuberculosis isolates from diverse geographic localities

Two genes (rpsL and rrs) with mutations associated with streptomycin resistance in Mycobacterium tuberculosis were characterized in 78 streptomycin-resistant and 61 streptomycin-susceptible isolates recovered from patients living in the United States, South America, Europe, Africa, and Asia. Fifty-four percent of the 78 resistant organisms had missense mutations in codon 43 of rpsL resulting in a K-43-->R substitution. Mutations in codon 88 of rpsL were also identified in four Asian isolates.

Inducibility of ethoxyresorufin deethylase and UDP-glucuronosyltransferase activities in two human hepatocarcinoma cell lines KYN-2 and Mz-Hep-1

Two human hepatoma cell lines, KYN-2 and Mz-Hep-1 were characterized in terms of glucuronidation capacity and inducibility of cytochrome P4501A1/1A2 and several UDP-glucuronosyltransferases (UGTs). Cytochrome P4501A1/1A2 activity was measured using 7-ethoxyresorufin and that of UGTs with 16 different substrates. The effects of dimethyl sulfoxide (DMSO), 3-naphthoflavone, alpha-naphthoflavone, and rifampicin on these drug-metabolizing enzyme activities were studied. DMSO treatment increased in a dose-dependent manner the ethoxyresorufin O-deethylase (EROD) activity in KYN-2 cells, while an opposite effect was observed in Mz-Hep-1 cells. In KYN-2 cells, EROD was more responsive toward beta-naphthoflavone treatment in combination with DMSO. This activity was enhanced in Mz-Hep-1 cells more than 83 times by beta-naphthoflavone. The enhancement of EROD activity by DMSO and beta-naphthoflavone treatments of KYN-2 cells was abolished by alpha-naphthoflavone treatment. In Mz-Hep-1, only the inducing effect of beta-naphthoflavone was abolished by alpha-naphthoflavone treatment. Rifampicin treatment of KYN-2 cells reversed both the DMSO and beta-naphthoflavone effects on the EROD activity. Glucuronidation of steroids, bile acids, fatty acids and drugs was effective in KYN-2 and Mz-Hep-1 cells. Both 1-naphthol glucuronidation and the level of UGT1*6 protein detected by immunoblot and supporting this activity were lowered by DMSO treatment and increased by beta-naphthoflavone treatment in KYN-2 cells. In Mz-Hep-1 cells, DMSO and beta-naphthoflavone had no effect on 1-naphthol glucuronidation activity. DMSO, beta-naphthoflavone and rifampicin also affected the glucuronidation of various substrates supported by different UGT isoforms. These results indicate that KYN-2 and Mz-Hep-1 cells can be used as new in vitro models for the studies of drug metabolism and the regulation of the corresponding enzymes.

Identification and antimicrobial activity of urinary metabolites of a rifamycin derivative in dog

1. Three metabolites of the antimicrobial agent 3'-hydroxy-5'-(4-isobutyl-1-piperazinyl)benzoxazinorifamycin (KRM-1648) were isolated from dog urine obtained after administration of a single oral dose. These metabolites of KRM-1648 were identified by mass spectrometry and 1H and 13C-nmr spectrometry. 2. Three metabolites of KRM-1648 were identified as 25-deacetyl KRM-1648, 30-hydroxy KRM-1648 and 25-deacetyl-30-hydroxy KRM-1648. 3. The antimicrobial activities of 25-deacetyl KRM-1648 were comparable with those of the parent compound, whereas 30-hydroxy KRM-1648 was equipotent and 2-8-fold less active than the parent compound against bacteria and mycobacteria, respectively.

Interaction of some drugs on the pharmacokinetics or pharmacodynamics of MPC-1304, a dihydropyridine Ca2+ antagonist

The aim of this study was to assess the pharmacokinetics and subsequent pharmacodynamic interaction of MPC-1304, a dihydropyridine Ca2+ antagonist, with other drugs in animal experiments. We measured the systolic blood pressure and heart rate of conscious spontaneously hypertensive rats implanted with battery-operated biotelemetry devices after combined administration of various drugs. Cimetidine (10 mg/kg) did not affect the reduction in systolic blood pressure and the increase in heart rate induced by MPC-1304, whereas it significantly increased the plasma concentration of a metabolite of MPC-1304 (M-1) compared to that detected when MPC-1304 was administered alone. When MPC-1304 was consecutively administered in combination with rifampicin (400 mg/kg) for 9 days, the plasma concentrations of MPC-1304 and of M-1 significantly decreased compared to those found when MPC-1304 alone was given. In spite of these reductions in plasma concentrations, rifampicin did not attenuate the hypotensive action induced by MPC-1304. When prazosin, reserpine, or methyldopa was administered in combination with MPC-1304, the hypotensive action was enhanced as compared to that by MPC-1304 alone or to that by the co-administered drug used alone (prazosin, reserpine, or methyldopa). Quinidine (10 mg/kg) affected neither the hypotensive action induced by MPC-1304 nor the plasma concentrations of MPC-1304 and M-1. These results indicate that cimetidine and rifampicin interact with MPC-1304 pharmacokinetically, without apparently changing the hypotensive action of MPC-1304, whereas quinidine does not affect the metabolism of MPC-1304, and that other hypotensive drugs, such as prazosin, reserpine, and methyldopa, potentiate the hypotensive action of MPC-1304.

Pharmacodynamics of once- or twice-daily levofloxacin versus vancomycin, with or without rifampin, against Staphylococcus aureus in an in vitro model with infected platelet-fibrin clots

We compared the pharmacodynamic activities of levofloxacin versus vancomycin, with or without rifampin, in an in vitro model with infected platelet-fibrin clots simulating vegetations. Infected platelet-fibrin clots were prepared with human cryoprecipitate, human platelets, calcium, thrombin, and approximately 10(9) CFU of organisms (MSSA 1199 and MRSA 494) per g and then were suspended via monofilament line into the in vitro model containing Mueller-Hinton growth medium. Antibiotics were administered by bolus injection into the model to simulate human pharmacokinetics; the regimens simulated included levofloxacin at dosages of 800 mg every 24 h (q24h) and 400 mg q12h, vancomycin at 1 g q12h, and rifampin at 600 mg q24h. Each model was run in duplicate over a 72-h period. Infected platelet-fibrin clots were removed in duplicate from each model, weighed, homogenized, serially diluted with sterile 0.9% saline, and plated on tryptic soy agar plates and plates containing antibiotics at 3, 6, and 12 times the MIC to evaluate the emergence of resistance. Time-kill curves were constructed by plotting the inoculum size versus time. Residual inoculum at 72 h was used to compare regimens. All levofloxacin regimens were significantly better than vancomycin monotherapy against both isolates (P < 0.002). Against MSSA 1199, levofloxacin q24h was significantly better than all other regimens, including levofloxacin q12h (P < 0.002); however, no difference between the levofloxacin monotherapy and combination therapy (with rifampin) regimens against MRSA 494 was seen. Killing activity for levofloxacin appeared to correlate better with the peak/MIC ratio than with the area under the curve/MIC ratio. The addition of rifampin significantly enhanced the activity of vancomycin but had little effect upon the activity of levofloxacin. For MRSA 494, vancomycin plus rifampin resulted in the greatest killing (P < 0.05). Development of resistance was not detected with any regimen. Levofloxacin may be a useful therapeutic alternative in the treatment of staphylococcal endocarditis, and further study with animal models of endocarditis or clinical trials are warranted.

[Resistance of Mycobacterium tuberculosis in the province of Castellón]

We conduced a cross-sectional study to determine the prevalence of resistant mycobacteria in our setting. All patients in whom M. tuberculosis had been isolated in cultures of clinical samples (119) between January 1992 and December 1993 took part in the study. Canetti's method of percentages was used for the study of sensitivity to the following drugs: isocyanide, rifampicin, streptomycin, ethambutol and para-aminosalicylic acid. Overall resistance of M. tuberculosis was 9.24%. Specifically, we found resistance to isocyanide in 5.9%, to streptomycin in 4.20%, to rifampicin in 5.04% and to ethambutol in 1.68%. Resistance was primary in 7% and secondary in 21.05%; 2% showed primary resistance to isocyanide, 1% to isocyanide and rifampicin, 2% to streptomycin, 1% to ethambutol and 1% to streptomycin and rifampicin. These resistance indices are in keeping with those published for other areas of Spain.

[The sat4 streptothricin acetyltransferase gene of Campylobacter coli: its distribution in the environment and use as epidemiological marker]

The main of this study is to give evidence about the spread of streptothricin resistance within Campylobacters which were isolated from animals, men and environmental sources. Streptothricin resistant Campylobacters were isolated over a five years period, when the use of streptothricin for ergotropic purposes was not allowed, from slurry of swine, slurry of cattle, waste water of a goose farm and waste water of a communal sewage treatment plant. The streptothricin resistance was found to be connected with resistances to kanamycin and streptomycin (MIC > 1024 micrograms/ml). For DNA-DNA-hybridisation we used a gene probe derived from the streptothricin acetyltransferase determinant sat4 from Campylobacter coli to find out epidemiological associations between Campylobacters of different origin. The hybridisation experiments show that all streptothricin resistant strains, which were isolated from one ecosystem or where an epidemiological link seems given, have sat4 positive signals at identical positions of the digested and blotted chromosomal DNA. The detection of the sat4 gene seems to be a good tool to discriminate clonal diversities within multiple antibiotic resistant Campylobacters.

[Multicenter transversal study of tuberculosis and drug resistance in Madrid (October 1993-April 1994)]

BACKGROUND

The aim of this study was to know the demographic profile of the new cases of tuberculosis (TB) and evaluate the current status of resistance to antituberculous drugs in Madrid, Spain.

METHODS

A transversal study was carried out in 8 hospitals (6 general hospitals) during 6 months. The clinical data of patients over 14 years old who presented a positive culture for Mycobacterium tuberculosis were collected in a protocolized method; the study on sensitivity to 5 drugs was independently and centrally performed (proportions method).

RESULTS

467 patients (339 from general hospitals), were included. In respect to the latter patients, 71% were under the age of 45 years and 36% presented coinfection with the human immunodeficiency virus (HIV). A sensitivity study was performed in 419 strains. Forty strains showed resistance to one or more of the antituberculous drugs; 13 were from the same center (CIC) in which a nosocomial outbreak of multiresistent TB had been detected among HIV infected patients. Resistence to more than one drug was observed in 29 cases (6.9%) and to rifampicine (RIF) and isoniacide (INH) in 24 patients (5.7%). On excluding the patients from the CIC these values were 16 (4.1%) and 13 (3.3%), respectively. Ninety-two percent of the strains with resistence to RIF + INH were from HIV positive patients. The rate of primary resistence to iNH in the patients with TB without HIV infection was 2.7%. This rate was 9.3% in those with HIV infection, and was 5.7% on excluding CIC cases. In patients with HIV infection most of the strains with primary resistence to INH also presented primary resistance to RIF.

CONCLUSIONS

More than one third of the patients with TB diagnosed in the general hospitals in Madrid, presented coinfection with HIV. In this population, the initial treatment for TB should probably begin with 4 drugs while awaiting the obliged sensitivity study.

Chlorochimaphilin: a new antibiotic from Moneses uniflora

A study of the antimicrobial compounds from Moneses uniflora resulted in the isolation of a novel compound, 8-chloro-2,7-dimethyl-1,4-naphthoquinone (8-chlorochimaphilin) (1), together with chimaphilin (2) and 3-hydroxychimaphilin (3) as the antimicrobial components. 2,7-Dimethyl-1,3-dihydroxynaphthyl 4-O-alpha-L-rhamnopyranoside (4) and 2,7-dimethoxy-1,4,8-trihydroxynaphthalene (6) were also isolated and identified.