Treatment correlates of successful outcomes in pulmonary multidrug-resistant tuberculosis: an individual patient data meta-analysis

BACKGROUND

Treatment outcomes for multidrug-resistant tuberculosis remain poor. We aimed to estimate the association of treatment success and death with the use of individual drugs, and the optimal number and duration of treatment with those drugs in patients with multidrug-resistant tuberculosis.

METHODS

In this individual patient data meta-analysis, we searched MEDLINE, Embase, and the Cochrane Library to identify potentially eligible observational and experimental studies published between Jan 1, 2009, and April 30, 2016. We also searched reference lists from all systematic reviews of treatment of multidrug-resistant tuberculosis published since 2009. To be eligible, studies had to report original results, with end of treatment outcomes (treatment completion [success], failure, or relapse) in cohorts of at least 25 adults (aged >18 years). We used anonymised individual patient data from eligible studies, provided by study investigators, regarding clinical characteristics, treatment, and outcomes. Using propensity score-matched generalised mixed effects logistic, or linear regression, we calculated adjusted odds ratios and adjusted risk differences for success or death during treatment, for specific drugs currently used to treat multidrug-resistant tuberculosis, as well as the number of drugs used and treatment duration.

FINDINGS

Of 12 030 patients from 25 countries in 50 studies, 7346 (61%) had treatment success, 1017 (8%) had failure or relapse, and 1729 (14%) died. Compared with failure or relapse, treatment success was positively associated with the use of linezolid (adjusted risk difference 0·15, 95% CI 0·11 to 0·18), levofloxacin (0·15, 0·13 to 0·18), carbapenems (0·14, 0·06 to 0·21), moxifloxacin (0·11, 0·08 to 0·14), bedaquiline (0·10, 0·05 to 0·14), and clofazimine (0·06, 0·01 to 0·10). There was a significant association between reduced mortality and use of linezolid (-0·20, -0·23 to -0·16), levofloxacin (-0·06, -0·09 to -0·04), moxifloxacin (-0·07, -0·10 to -0·04), or bedaquiline (-0·14, -0·19 to -0·10). Compared with regimens without any injectable drug, amikacin provided modest benefits, but kanamycin and capreomycin were associated with worse outcomes. The remaining drugs were associated with slight or no improvements in outcomes. Treatment outcomes were significantly worse for most drugs if they were used despite in-vitro resistance. The optimal number of effective drugs seemed to be five in the initial phase, and four in the continuation phase. In these adjusted analyses, heterogeneity, based on a simulated I² method, was high for approximately half the estimates for specific drugs, although relatively low for number of drugs and durations analyses.

INTERPRETATION

Although inferences are limited by the observational nature of these data, treatment outcomes were significantly better with use of linezolid, later generation fluoroquinolones, bedaquiline, clofazimine, and carbapenems for treatment of multidrug-resistant tuberculosis. These findings emphasise the need for trials to ascertain the optimal combination and duration of these drugs for treatment of this condition.

FUNDING

American Thoracic Society, Canadian Institutes of Health Research, US Centers for Disease Control and Prevention, European Respiratory Society, Infectious Diseases Society of America.

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Prosthetic valvular endocarditis. A 12-year review

A retrospective examination was made of a total of 48 patients with infected prosthetic cardiac valves implanted in 1,236 patients during 1960-1972. Survival rate of the valvular infections was 40%. The purpose of the study was to determine the factors which aided or decreased patient survival and to develop a program of treatment with antimicrobial agents. Numerous antimicrobics and a variety of dosage schedules were used. Of 19 surviving patients, medical treatment alone was effective in 14, despite the continued presence of a valvular prosthesis. Reoperation was successful in five of nine patients. Lifelong chemoprophylactic or suppressive therapy was shown to be unnecessary to prevent relapse in 12 survivors. Prompt surgical replacement is indicated if antimicrobial therapy fails to eradicate infection of a prosthetic valve. A more systematic approach to antimicrobial therapy should improve survival of medically treated infections. Recommendations are made for prevention and treatment of prosthetic valvular endocarditis.

Effect of clarithromycin regimen for Mycobacterium avium complex pulmonary disease

We have investigated the efficacy of a clarithromycin-containing four-drug regimen for Mycobacterium avium complex (MAC) pulmonary disease in 46 patients without acquired immunodeficiency syndrome (AIDS). The patients were 14 males and 32 females with a mean age of 60.9 +/- 11.5 yr. Patients received 10 mg/kg/d of clarithromycin plus ethambutol, rifampin, and initial kanamycin and subsequent quinolone for 24 mo. Seven patients (15.2%) were dropped in the first 6 mo. Among 39 patients who received more than 6 mo of therapy, 28 patients (71.8%) converted their sputa to negative: 26 of 31 patients (83.9%) infected with clarithromycin-susceptible strains and two of eight patients (25.0%) with resistant or intermediate strains. The timing of sputum conversion was 3.6 +/- 1.9 mo, with a range of 2 to 9 mo. The conversion rate was significantly lower in patients who were infected with clarithromycin-resistant or intermediate strains, who had had prior therapy (55.0% versus 89.5%), or who were acid-fast bacilli (AFB) smear-positive at entry (60.7% versus 100%). The age and sex of patients, the species of pathogen (M. avium or M. intracellulare), type and extent of the disease, and the use of kanamycin did not significantly affect the conversion rate. Although the regimen was efficacious for newly treated patients, frequent adverse reactions and a low conversion rate of sputum in retreated patients are problems that remain to be solved.

Role of hand contamination of personnel in the epidemiology of gram-negative nosocomial infections

Gram-negative organisms, responsible for a high rate of colonization and infection in an intensive care nursery, were recovered frequently from hands of personnel, despite regular hand antisepsis. In sequential hand cultures contamination of hands by gram-negative organisms was transient in some nurses, but active multiplication of the organisms occurred on the hands of others and in a few nurses a temporary carrier state appeared to exist. The results of this study suggest that the hands of hospital personnel may serve not only as a passive vehicle in the nosocomial transmission of gran-negative bacteria, but also may constitute a reservoir of nosocomial organisms.

Drug resistance in Salmonella typhimurium and its implications

A rise in Salmonella typhimurium infection was observed in calves in Britain during 1964-6, follwing the adoption of the intensive farming method. A single phage type of S. typhimurium, type 29, was incriminated as the major pathogen. Attempts to treat and control the disease with a range of antibiotics were ineffective, but resulted in the acquisition of transferable multiple drug resistance by type 29. The transmission of drug-resistant type 29, directly or indirectly, from bovines to man resulted in many human infections. Transferable drug resistance reaching man from enterobacteria of animal origin may ultimately enter specifically human pathogens. Infections such as that caused by type 29 can be eliminated, not by the massive use of antibiotics but by improvement in conditions of animal husbandry and reduction in the opportunities for the initiation and spread of the disease. A reappraisal is needed of the methods of using antibiotics to determine how these methods can be improved, in order to conserve the long-term efficacy of the antibiotics.

Management of acute chorioamnionitis

Acute chorioamnionitis has been recognized as a major threat to both mother and fetus, but there has been little study of its therapy. On this service, the plan of management consists of parenteral, broad-spectrum antibiotic therapy and prompt action to effect delivery. Cesarean section was generally performed only when there were additional obstetric indications. No arbitrary time limit was set for the diagnosis-to-delivery interval. The perinatal mortality rate was increased fourfold, but few deaths could be attributed to infection. Maternal outcome was usually good following vaginal delivery and more complicated following abdominal delivery. Over 90% of patients were delivered within 12 hours of diagnosis of chorioamnionitis.

Antibiotic use during infancy promotes a shift in the T(H)1/T(H)2 balance toward T(H)2-dominant immunity in mice

BACKGROUND

Recent epidemiologic studies indicate that antibiotic use in infancy may be associated with an increased risk of development of atopy; however, its precise mechanism remains to be elucidated.

OBJECTIVE

The purpose of this study is to clarify whether one such antibiotic, kanamycin, affects the T(H)1/T(H)2 balance.

METHODS

BALB/c mice at 3 and 52 weeks of age were orally administered 600 mg/d kanamycin sulfate for 7 consecutive days. Blood samples were collected on weeks 0, 10, 18, and 26 after the cessation of kanamycin treatment, and the effect of the kanamycin treatment on the T(H)1/T(H)2 balance was evaluated on the basis of both the in vivo antibody levels and the in vitro splenocyte cytokine secretion pattern.

RESULTS

The administration of kanamycin increased the serum levels of total IgG1 and IgE while decreasing the serum IgG2a levels. Moreover, when spleen cells were stimulated with immobilized anti-CD3 antibody in vitro, such kanamycin treatment enhanced the in vitro IL-4 secretion while reducing the in vitro IFN-gamma secretion. The basal IL-12 p70 secretion levels of splenic dendritic cells in the kanamycin-treated mice were lower than those in the control mice, although no significant difference was seen in IL-12 p40 levels between either group of mice.

CONCLUSION

These results suggested that antibiotic use during infancy may indeed quantitatively disturb, qualitatively disturb, or both the intestinal microflora and thereby prevent postnatal T(H)1 cell maturation, thus resulting in a T(H)2-polarized immune deviation.

Prophylactic oral antimicrobial agents in elective colonic surgery. A controlled trial

A controlled trial has been carried out in 50 patients undergoing elective colonic surgery to assess the efficacy of prophylactic oral metronidazole specifically directed against anaerobic colonic microflora in combination with kanamycin to reduce the aerobic flora. A control group received dietary and mechanical preparation alone. A significant reduction of both aerobic and anaerobic colonic microflora was achieved in the group receiving prophylactic antimicrobial agents, and this was reflected in a significant reduction in postoperative wound infections. 1 control patient died from Bacteroides septicaemia. No toxic or other side-effects from this prophylactic regimen occurred in this trial.

Multiple of isolates of Pseudomonas aeruginosa with differing antimicrobial susceptibility patterns from patients with cystic fibrosis

Clinical isolates of Pseudomonas aeruginosa from patients with cystic fibrosis were studied in an effort to determine the unique characteristics of the infecting strains and to elucidate the pattern of colonization. Of 413 patients studied, 81% were chronically infected with P. aeruginosa. Patients from whom P. aeruginosa was never or only occasionally isolated were in better clinical condition than the chronically infected patients. Isolates were classified into six morphologic varieties: classic, rough, mucoid, gelatinous, dwarf, and enterobacter. Most patients had two or more of these varieties. Such multiple varieties from the same individual were of the same serotype but often differed in antibiotic susceptibility as determined by both the disk and the minimal inhibitory concentration methods. These differences were apparent when mucoid strains were compared with nonmucoid strains and when nonmucoid strains were compared with one another. Studies of antibiotic susceptibility should be performed on each morphologically different type of P. aeruginosa obtained from patients with cystic fibrosis.

Comparison between oral antibiotics and probiotics as bowel preparation for elective colon cancer surgery to prevent infection: prospective randomized trial

BACKGROUND

We have already reported that, for patients undergoing elective colon cancer operations, perioperative infection can be prevented by a single intravenous dose of an antibiotic given immediately beforehand if mechanical bowel preparation and the administration of oral antibiotics are implemented. Synbiotics has been reported to reduce the rate of infection in patients after pancreatic cancer operations. The effectiveness of oral antibiotics and probiotics in preventing postoperative infection in elective colon cancer procedures was examined in a randomized controlled trial.

METHODS

Three hundred ten patients with colon cancer randomly were assigned to one of three groups. All patients underwent mechanical bowel preparation and received a single intravenous dose of flomoxef immediately before operation. Probiotics were administered in Group A; oral antibiotics were administered in Group B; and neither probiotics nor oral antibiotics were administered in Group C. Stool samples were collected 9 and 2 days before and 7 and 14 days after the procedure. Clostridium difficile toxin and the number of bacteria in the intestine were determined.

RESULTS

The rates of incisional surgical-site infection were 18.0%, 6.1%, and 17.9% in Groups A, B, and C, and the rates of leakage were 12.0%, 1.0%, and 7.4% in Groups A, B, and C, respectively, indicating that both rates were lesser in Group B than in Groups A and C (P = .014 and P = .004, respectively). The detection rates of C. difficile toxin were not changed among the three groups.

CONCLUSION

We recommend oral antibiotics, rather than probiotics, as bowel preparation for elective colon cancer procedures to prevent surgical-site infections.

Serratia marcescens endocarditis: a regional illness associated with intravenous drug abuse

From 1969 to 1974, 19 cases of Serratia marcescens endocarditis were observed in the San Francisco Bay Area. Seventeen patients were intravenous drug users, and Serratia caused 14% of all addict-associated endocarditis in San Francisco. Serratia strains were nonpigmented and had typical antibiotic sensitivities, except that 9 of the isolates exhibited colonial variation, with each variant having different antibiotic sensitivities. Aortic or mitral valves were involved in 13 patients, and heart failure developed in 9 of these. Twelve patients had embolic episodes to brain, iliofemoral arteries, or lung. Five of 6 patients with tricuspid valvulitis were cured by antibiotics either with (1) or without excision of the valve. All 12 patients with aortic or mitral valvulitis treated medically died; 11 had unremitting sepsis. Aortic valve replacement and antibiotics were effective in 1. Gentamicin combined with either carbenicillin or chloramphenicol was the most effective treatment regimen.

The value of prophylactic antibiotics in transurethral prostatic resection: a controlled trial, with observations on the origin of postoperative infection

Prophylactic antibiotics significantly decrease the incidence of urinary tract infection following endoscopic prostate resection. They are ineffective in reducing the incidence of postoperative fevers, or in reducing the frequency of positive blood cultures during or after operation. A majority of prostate glands harbour colonies of potentially pathogenic organisms, and these are the commonest source of infection of the urinary tract following release by prostatic surgery.

Improved penetration of aminoglycosides and fluorozuinolones into the aqueous humour of patients by means of Acuvue contact lenses

OBJECTIVES

In order to improve the penetration of topically applied drugs in ophthalmology, the suitability of hydrophilic contact lenses (Acuvue, Vistacon, power -1.0 D) as a drug delivery system for antibiotics was tested. A prospective study was undertaken to determine the transcorneal penetration of five topically applied aminoglycosides and fluoroquinolones into the aqueous humour of patients.

METHODS

Two hundred and sixty-five patients undergoing cataract extraction received 0.3% gentamicin, kanamycin, tobramycin, ciprofloxacin or ofloxacin solution by two different modes of administration: either as eye drops (nine drops every 15 min, starting 2 h prior to surgery) or by means of a drug delivery system (Acuvue contact lenses soaked for 1 h in eye drop solution without preservatives, 15 h prior to surgery). At the beginning of cataract extraction, 50-100 microl aqueous fluid was aspirated from the anterior chamber and immediately stored at -80 degrees C. Antibiotic concentrations were measured using fluorescence polarisation immunoassays (aminoglycosides) or high-performance liquid chromatography (fluoroquinolones).

RESULTS

After soaking for 1h in 0.3% eye drop solutions, Acuvue contact lenses released about 190-250 microg aminoglycoside and ofloxacin and 1000 microg ciprofloxacin. These amounts are considerably lower or in the same order of magnitude than obtained with application of eye drops (1350 microg). From the aminoglycosides tested, only gentamicin and tobramycin, but not kanamycin, were able to penetrate into the aqueous humour of patients. After the wearing of antibiotic-soaked lenses, mean aqueous humour concentrations were higher than after the use of eye drops. This difference reached significance in tobramycin (1.09 (1.30) microg x ml(-1) vs 0.49 (0.79) microg x ml(-1)), ciprofloxacin (1.23 (0.60) microg x ml(-1) vs 0.38 (0.33) microg x ml(-1)) and ofloxacin (5.55 (2.53) microg x ml(-1) vs 0.56 (0.37) microg x ml(-1)). The percentage of patients with aqueous humour concentration above the MIC90 of Staphylococcus epidermidis, the most common cause of postoperative endophthalmitis, was 92% and 100% after wearing ciprofloxacin- or ofloxacin-soaked lenses, respectively.

CONCLUSION

Gentamicin and tobramycin penetrated into the aqueous humour of patients, whereas kanamycin was not able to overcome the corneal barrier. Acuvue contact lenses soaked in 0.3% eye drop solutions can release sufficient amounts of gentamicin, ciprofloxacin and ofloxacin to produce bacteriostatic concentrations in the humor aquosus. Acuvue contact lenses can be recommended as a drug delivery system for fluoroquinolones.

Spatial-temporal imaging of bacterial infection and antibiotic response in intact animals

We describe imaging the luminance of green fluorescent protein (GFP)-expressing bacteria from outside intact infected animals. This simple, nonintrusive technique can show in great detail the spatial-temporal behavior of the infectious process. The bacteria, expressing the GFP, are sufficiently bright as to be clearly visible from outside the infected animal and recorded with simple equipment. Introduced bacteria were observed in several mouse organs including the peritoneal cavity, stomach, small intestine, and colon. Instantaneous real-time images of the infectious process were acquired by using a color charge-coupled device video camera by simply illuminating mice at 490 nm. Most techniques for imaging the interior of intact animals may require the administration of exogenous substrates, anesthesia, or contrasting substances and require very long data collection times. In contrast, the whole-body fluorescence imaging described here is fast and requires no extraneous agents. The progress of Escherichia coli-GFP through the mouse gastrointestinal tract after gavage was followed in real-time by whole-body imaging. Bacteria, seen first in the stomach, migrated into the small intestine and subsequently into the colon, an observation confirmed by intravital direct imaging. An i.p. infection was established by i.p. injection of E. coli-GFP. The development of infection over 6 h and its regression after kanamycin treatment were visualized by whole-body imaging. This imaging technology affords a powerful approach to visualizing the infection process, determining the tissue specificity of infection, and the spatial migration of the infectious agents.