Ceftaroline Plus Ampicillin Against Gram-Positive Organisms: Results from E-Test Synergy Assays

In an era of increasing drug resistance and limited numbers of antimicrobials in the drug production pipeline, healthcare-associated infections represent a growing public health threat. When therapeutic options are limited, clinicians often resort to using antimicrobial combinations that produce a synergistic effect on the target pathogen. Novel antibiotics are therefore welcome in the daily practice of medicine. For example, ceftaroline is a broad-spectrum cephalosporin active against a variety of bacteria, including methicillin-resistant Staphylococcus aureus, but with limited activity against enterococci, particularly Enterococcus faecium. In this study, we tested the efficacy of ceftaroline against clinical isolates of gram-positive bacteria (S. aureus, Enterococcus faecalis, and E. faecium) by the broth microdilution and E-test assays, and then evaluated the synergistic effect of ceftaroline and ampicillin using the E-test method. The time-kill assay was used to confirm the data on selected strains. This drug combination has been recently shown to be effective against E. faecalis and could offer the advantage of cost-effectiveness (compared to other synergistic associations) as well as good tolerability. The E-test was chosen because of its relative simplicity of use that makes it suitable for routine clinical laboratories as a quick tool to guide clinicians when confronted with difficult-to-treat infections that may require an empirical approach. Our results indicate the presence of a synergistic effect of ceftaroline and ampicillin on most of the strains used, especially E. faecium and E. faecalis. The fact that two of those Enterococcus strains were vancomycin resistant suggests that the possible use of this combination for combating the spread of vancomycin-resistant enterococci should be explored.

Evaluation of the inactivation effect of Triton X-100 on Ebola virus infectivity

BACKGROUND

The recent Ebola virus disease outbreak occurred in West Africa since December 2013 highlighted the need of appropriate virus inactivation procedures to be set up to allow the necessary processing of specimens outside BSL-4 facilities and to perform laboratory tests without affecting clinical decisions. For this purpose, international guidelines suggest the pre-treatment of the samples with Triton X-100.

OBJECTIVES

Due to the limited scientific evidence about the efficacy of Triton X-100 on enveloped-viruses, the aim of this work was to evaluate the effect of Triton X-100 on the virus infectivity and to establish the optimal conditions for its use.

STUDY DESIGN

We evaluated the effect of Triton X-100 on the infectivity of enveloped-viruses such as West Nile virus (WNV) and Ebola virus (EBOV) at different experimental conditions. The residual virus infectivity was measured by limiting dilution assay on Vero E6 cells. Repeated experiments were performed, as specified, and for the titration of residual infectivity each dilution was tested in triplicate.

RESULTS

Results obtained with WNV showed that infectivity was reduced by 6 Logs, after 1h of treatment with different concentrations of Triton X-100 (ranging from 0.5% to 0.05%). This effect was not time-dependent using 0.1% Triton X-100. Subsequently, we applied the method on EBOV and one hour exposure to 0.1% Triton X-100 strongly affected EBOV infectivity (4 Logs of infectivity reduction).

CONCLUSIONS

We report that Triton X-100, when used alone, is able to strongly reduce the infectivity of a classical enveloped virus such as WNV and we provide, for the first time, scientific evidence that 0.1% Triton X-100 efficaciously affect Ebola virus infectivity. Even though a complete virus inactivation is not achieved, Triton X-100 certainly can contribute to mitigate the risk for the workers of accidental infection and improve the overall safety of the laboratory procedures. Further studies must be performed to deeply investigate alternative solutions able to balance higher level of safety and good performance in clinical chemistry and hematology parameters analysis, necessary for the appropriate and effective management of EVD patients.

Isolation of KPC 3-producing Enterobacter aerogenes in a patient colonized by MDR Klebsiella pneumoniae

We describe the interspecies transmission of the plasmid-mediated blaKPC-3 gene, which confers carbapenem resistance, between clinically relevant gram-negative bacteria in a single patient. A KPC-3 producing Enterobacter aerogenes was isolated from a hospitalized patient previously colonized and then infected by a Klebsiella pneumoniae ST101 carrying the blaKPC-3 gene. The strains showed identical plasmids. Since intense horizontal exchanges among bacteria can occur in the gut, clinicians should be aware that patients colonized by carbapenem-resistant K. pneumoniae could become carriers of other carbapenem-resistant Enterobacteriaceae.

Bacteremic Infectability of Vascular Grafts: An Experimental Study

The present study was undertaken with the aim of defining the differences, if any, in bacteremic infectability of some currently available arterial grafts.

The following prostheses were investigated:

• two kinds of expanded polytetrafluoroethylene (PTFE)

• Dacron knitted double velour

• Dacron knitted pretreated with gelatin

Forty beagle dogs were used . In each animal the infrarenal aorta was resected and replaced by means of ϕ.6 mm segment of:

• PTFE type I 10 dogs

• PTFE type II 10 dogs

• Dacron knitted double velour 10 dogs

• Dacron knitted pretreated with gelatin 10 dogs

At the end of the operation, each animal was administered IV with 100 mL of normal saline containing a suspension of Staphylococcus aureus coagulase-posi tive phage type 5504. The bacterial load was 105in 5 animals of each group, 107in the remaining 5.

The graft was retrieved after forty-five days and studied in the microbiology laboratory (study of graft homogenate) and in the pathology laboratory (study by conventional microscopy of graft healing). When culture yielded a strain of Staph. aureus, this was retyped for phage 5504 specificity.

All grafts were patent at the end of the experiment: partial thrombosis was, however, observed, coupled with a frank perigraft inflammation in:

• 3 PTFE type 1 (2 Staph. 105, 1 Staph. 107)

• 1 PTFE type 2 (Staph . 105)

• 1 Dacron knitted double velour (Staph . 107 )

Baterial colonies within the graft tissue were evident at microscopy in 4 PTFE grafts and in 1 gelatin-pretreated graft.

Culture was positive and specific in all the gelatin-treated Dacron grafts and in 60% of the nonpretreated Dacron and PTFE grafts.

An optimal result (good healing, no inflammation, no infection) was observed only in 3 PTFE and in 2 "conventional" Dacron grafts.

The possibility is suggested that bacteria may be harbored in graft tissue without any clinically evident effect; moreover, some late graft infection could be attributable to an early bacteremic contamination.

Invasive Candidiasis due to Candida Norvegensis in a Liver Transplant Patient: Case Report and Literature Review

Candida norvegensis is an emerging fluconazole-resistant pathogen isolated in most cases from skin and mucous membranes of immunocompromized patients. Documented invasive candidiasis (IC) due to C. norvegensis has been rarely reported, thus the clinical features of patients at risk for this pathogen are poorly defined. We report a liver transplant patient who developed IC due to C. norvegensis and review other cases of C. norvegensis IC published in the literature.

In vitro activity of doripenem in combination with various antimicrobials against multidrug-resistant Acinetobacter baumannii: possible options for the treatment of complicated infection

AIMS

The aim of this study was to evaluate the in vitro activity of doripenem (DOR) alone and in combination with a variety of commonly used anti-Acinetobacter chemotherapeutic agents against 22 primary multidrug-resistant (MDR) Acinetobacter baumannii isolates (including 17 isolates that were resistant to DOR) from Intensive Care Unit patients. Antibiotic interactions were evaluated using the chequerboard method and the time-kill assay.

RESULTS

Considering all antimicrobials in combination with DOR, chequerboard analysis showed synergy in 13 A. baumannii strains (54.2%). Seven strains (29.2%) showed ≥2 synergistic interactions. DOR showed synergy in combination with tigecycline (TIG) (eight strains), colistin (COL) (eight strains), amikacin (AMK) (four strains), ampicillin/sulbactam (two strains), and rifampicin (one strain). Remarkably, synergistic effects were detected only in DOR nonsusceptible strains. Time-kill assays confirmed synergy in eight isolates (giving 10 synergistic interactions) for DOR in combination with TIG (n=4), COL (n=5), and AMK (n=1). No antagonistic interactions were observed with both methods.

CONCLUSIONS

This study demonstrates the in vitro synergistic activity of DOR in combination with TIG, COL, and AMK against DOR-resistant A. baumannii strains, opening the way to in vivo assessment of novel combination therapies for treatment of infections caused by MDR A. baumannii.

Clostridium difficile infection in Italian urban hospitals: data from 2006 through 2011

BACKGROUND

In developed countries, Clostridium difficile infection (CDI) represents an emerging threat in terms of morbidity and mortality rates. In our country limited CDI epidemiological data can be found.

METHODS

Stool samples tested for C. difficile toxins from January 2006 to December 2011 in 5 large hospitals in Rome, Italy, were considered in the analysis. Repeated samples taken ≤ 2 months after a positive result were excluded.

RESULTS

A total of 402 CDI episodes were identified. The incidence of CDI episodes progressively increased from 0.3 in 2006 to 2.3 per 10,000 patient-days in 2011. CDI episodes mostly occurred in patients > 60 years of age (77%). The >80 year-old age class reported the highest percentage of CDI episodes on tested samples (16%). Eighty percent (80%) of CDI episodes occurred in medical wards followed by surgery (10.2%) and intensive care units (9.8%).

CONCLUSIONS

A significant increasing incidence of CDI episodes over the study period was observed during the years (p<.001), particularly in the older age groups. Medical wards experienced the highest number of CDI episodes as compared to intensive care and surgical wards. The increasing rate of CDI episodes over the last six years in our country, is alarming; urgent improvements in the surveillance systems and control programs are advisable.

High rate of colistin resistance among patients with carbapenem-resistant Klebsiella pneumoniae infection accounts for an excess of mortality

Carbapenem-resistant Klebsiella pneumoniae (CR-KP) is becoming a common cause of healthcare-associated infection in Italy, with high morbidity and mortality. Prevalent CR-KP clones and resistance mechanisms vary between regions and over time. Therapeutic approaches and their impact on mortality have to be investigated. We performed a prospective study of patients with CR-KP isolation, hospitalized in nine hospitals of Rome, Italy, from December 2010 to May 2011, to describe the molecular epidemiology, antibiotic treatment and risk factors for mortality. Overall, 97 patients (60% male, median age 69 years) were enrolled. Strains producing blaKPC-3 were identified in 89 patients, blaVIM in three patients and blaCTX-M-15 plus porin defects in the remaining five patients. Inter-hospital spread of two major clones, ST512 and ST258, was found. Overall, 36.1% and 20.4% of strains were also resistant to colistin and tigecycline, respectively. Infection was diagnosed in 91 patients who received appropriate antibiotic treatment, combination therapy and removal of the infectious source in 73.6%, 59.3% and 28.5% of cases, respectively. Overall, 23 different antibiotic regimens were prescribed. In-hospital mortality was 25.8%. Multivariate analysis adjusted for appropriate treatment, combination therapy and infectious-source removal, showed that Charlson comorbidity score, intensive-care unit onset of infection, bacteraemia and infection due to a colistin-resistant CR-KP strain were independent risk factors for mortality. The spread of clones producing K. pneumoniae carbapenemases, mainly ST258, is currently the major cause of CR-KP infection in central Italy. We observed a high rate of resistance to colistin that is independently associated with worse outcome.

The superoxide reductase from the early diverging eukaryote Giardia intestinalis

Unlike superoxide dismutases (SODs), superoxide reductases (SORs) eliminate superoxide anion (O(2)(•-)) not through its dismutation, but via reduction to hydrogen peroxide (H(2)O(2)) in the presence of an electron donor. The microaerobic protist Giardia intestinalis, responsible for a common intestinal disease in humans, though lacking SOD and other canonical reactive oxygen species-detoxifying systems, is among the very few eukaryotes encoding a SOR yet identified. In this study, the recombinant SOR from Giardia (SOR(Gi)) was purified and characterized by pulse radiolysis and stopped-flow spectrophotometry. The protein, isolated in the reduced state, after oxidation by superoxide or hexachloroiridate(IV), yields a resting species (T(final)) with Fe(3+) ligated to glutamate or hydroxide depending on pH (apparent pK(a)=8.7). Although showing negligible SOD activity, reduced SOR(Gi) reacts with O(2)(•-) with a pH-independent second-order rate constant k(1)=1.0×10(9) M(-1) s(-1) and yields the ferric-(hydro)peroxo intermediate T(1); this in turn rapidly decays to the T(final) state with pH-dependent rates, without populating other detectable intermediates. Immunoblotting assays show that SOR(Gi) is expressed in the disease-causing trophozoite of Giardia. We propose that the superoxide-scavenging activity of SOR in Giardia may promote the survival of this air-sensitive parasite in the fairly aerobic proximal human small intestine during infection.

Salmonella enterica ssp. arizonae infection in a 43-year-old Italian man with hypoglobulinemia: a case report and review of the literature

Introduction

Salmonella enterica ssp. arizonae is an uncommon human pathogen with serious infections reported in immunocompromised hosts. In Europe, only a few cases have been described. Patients with this infection usually have a history of contact with reptiles or travel abroad. We present a case report of infection in a patient with hypoglobulinemia and a literature review.

Case presentation

We describe the case of a 43-year-old Caucasian Italian man with hypoglobulinemia who presented to our hospital with sepsis and diarrhea. A stool culture yielded S. enterica ssp. arizonae. Our patient was treated with oral ciprofloxacin and made a full recovery. We also present a review of the cases of S. enterica ssp. arizonae infections previously reported in Europe.

Conclusions

The majority of infections from S. enterica ssp. arizonae occur in patients who are immunocompromised. Data from the literature suggests that it may be difficult to eradicate the bacteria and thus, prolonged antibiotic courses are often used. It would be advisable for clinicians to investigate for pre-existing immune dysfunction if S. enterica ssp. arizonae is isolated. In Italy, although there have only been a few cases, the likely route of transmission remains unclear and requires further surveillance.

Giardia intestinalis escapes oxidative stress by colonizing the small intestine: A molecular hypothesis

Giardia intestinalis is the microaerophilic protozoon causing giardiasis, a common infectious intestinal disease. Giardia possesses an O(2) -scavenging activity likely essential for survival in the host. We report that Giardia trophozoites express the O(2) -detoxifying flavodiiron protein (FDP), detected by immunoblotting, and are able to reduce O(2) to H(2) O rapidly (∼3 μM O(2) × min × 10(6) cells at 37 °C) and with high affinity (C(50) = 3.4 ± 0.7 μM O(2)). Following a short-term (minutes) exposure to H(2) O(2) ≥ 100 μM, the O(2) consumption by the parasites is irreversibly impaired, and the FDP undergoes a degradation, prevented by the proteasome-inhibitor MG132. Instead, H(2) O(2) does not cause degradation or inactivation of the isolated FDP. On the basis of the elevated susceptibility of Giardia to oxidative stress, we hypothesize that the parasite preferentially colonizes the small intestine since, compared with colon, it is characterized by a greater capacity for redox buffering and a lower propensity to oxidative stress.

Flavohemoglobin and nitric oxide detoxification in the human protozoan parasite Giardia intestinalis

Flavohemoglobins (flavoHbs), commonly found in bacteria and fungi, afford protection from nitrosative stress by degrading nitric oxide (NO) to nitrate. Giardia intestinalis, a microaerophilic parasite causing one of the most common intestinal human infectious diseases worldwide, is the only pathogenic protozoon as yet identified coding for a flavoHb. By NO amperometry we show that, in the presence of NADH, the recombinant Giardia flavoHb metabolizes NO with high efficacy under aerobic conditions (TN=116+/-10s(-1) at 1microM NO, T=37 degrees C). The activity is [O(2)]-dependent and characterized by an apparent K(M,O2)=22+/-7microM. Immunoblotting analysis shows that the protein is expressed at low levels in the vegetative trophozoites of Giardia; accordingly, these cells aerobically metabolize NO with low efficacy. Interestingly, in response to nitrosative stress (24-h incubation with 5mM nitrite) flavoHb expression is enhanced and the trophozoites thereby become able to metabolize NO efficiently, the activity being sensitive to both cyanide and carbon monoxide. The NO-donors S-nitrosoglutathione (GSNO) and DETA-NONOate mimicked the effect of nitrite on flavoHb expression. We propose that physiologically flavoHb contributes to NO detoxification in G. intestinalis.

HIV-related pneumococcal lung disease: does highly active antiretroviral therapy or bacteremia modify radiologic appearance?

We reviewed chest radiographs of 57 HIV-infected patients with pulmonary diseases in whom Streptococcus pneumoniae was the sole respiratory pathogen isolated to evaluate whether highly active antiretroviral therapy (HAART) or bacteremia modify radiographic appearance. Pneumococcal lung disease presented as lobar pneumonia in 40% of the cases, 54% of whom were on HAART; as bronchopneumonia in 42%, 58% on HAART; as interstitial infiltrates in 17%, 60% on HAART. Bacteremia was observed 38 times in 23 patients with CD4 less than 200/mm(3), and in 15 with CD4 greater than 200/mm(3) (p > 0.05). HAART does not significantly influences radiographic appearances of lung disease caused by Streptococcus pneumoniae (p > 0.05). Immunosuppression induced by HIV infection was a major risk factor for development of pneumococcal lung disease (p = 0.04) and influences radiographic appearance; bronchopneumonia (p = 0.006), in particular multifocal (p = 0.008), which was more frequent in subjects with CD4 less than 200/mm(3). Bacteremia influences radiographic appearance of pneumococcal lung disease; lobar pneumonia was more frequent (p = 0.003), and considering CD4 cell count, was more frequent if CD4 cell count was above 200/mm(3). An original finding of this study was the frequency of interstitial changes. This pattern of pneumonia, found in 17% of our patients, could represent a difference between HIV-seropositive and -seronegative subject in displaying pneumococcal lung disease.

HIV-related bronchopulmonary infection by Pseudomonas aeruginosa in the HAART era: radiological findings

PURPOSE

To evaluate whether highly active antiretroviral therapy (HAART) modifies radiographic appearances of Pseudomonas aeruginosa bronchopulmonary infection in HIV-infected patients. P. aeruginosa is increasingly reported as a respiratory pathogen in HIV+ patients with very low levels of CD4 lymphocytes. Few studies have analyzed the radiological presentation of bronchopulmonary disease that occurs in HAART-treated patients.

MATERIAL AND METHODS

We retrospectively reviewed the chest radiographs of 46 HIV-infected patients with bronchopulmonary diseases in which P. aeruginosa was the sole respiratory pathogen that was isolated. All cases were community-acquired infection. Twenty-four of the patients were on HAART treatment, and 22 were not. Chest radiographs were assessed for the presence and distribution of parenchymal consolidation, reticular or reticulonodular infiltrates, bronchial wall thickening, ground-glass opacities, cavitation, pleural effusion, and adenopathies. Statistical analysis was done using Epi-Info version 6 (CDC, Atlanta, GA, USA).

RESULTS

Normal chest radiographs were observed in 11 patients. Eight of these 11 (73%) were receiving HAART, and 3/11 (27%) were not. The most common radiographic abnormality was bronchopneumonia, present in 24 of 46 patients (52%): in 10 of 24 (42%) patients with HAART and 14 of 22 (64%) without. Cavitation was seen in 1 of 24 (4%) patients with HAART and in 5 of 22 (23%) without HAART.

CONCLUSION

Cavitation was more frequent in patients that were not receiving HAART, and normal chest radiographs were more frequently seen in patients on HAART.

Purification and characterization of an antifungal thaumatin-like protein from Cassia didymobotrya cell culture

A 23-kDa antifungal thaumatin-like protein was isolated and purified from Cassia didymobotrya (Fres.) cell cultures for the first time. The protein was secreted in the culture medium, but it could be also isolated after elution of whole cells with a 0.5 M CaCl(2) solution. Treatment of the cells with laminarin oligosaccharides or salicylic acid, but not with NaCl, resulted in enhancement of expression of the protein. A rapid purification protocol was used based on cationic exchange chromatography. The protein, with a highly basic character (pI 10), has an exact molecular mass of 23034 Da, as determined by MALDI-ToF mass spectrometry analysis. N-terminal sequencing of the intact polypeptide and the sequencing of two internal tryptic peptides indicated significant identity with other thaumatin-like proteins (TLP). The protein exerted antifungal activity towards some Candida species showing EC(50) values comparable to those of other antifungal TLPs. The collected data lead to classify this TLP as a new PR-5 protein.

Pulmonary tuberculosis in HIV-infected patients presenting with normal chest radiograph and negative sputum smear

BACKGROUND

HIV-infected patients with pulmonary tuberculosis exhibit atypical radiological presentation and negative sputum smear more frequently than their HIV-negative counterparts.

PATIENTS AND METHODS

We performed a retrospective study based on a chart review of 146 HIV-infected patients with pulmonary symptoms and culture-proven pulmonary tuberculosis. We compared clinical characteristics and the outcome in 71 patients (49%) with positive sputum smear (SS+), 62 patients (42%) with negative sputum smear/abnormal chest X-ray (SS-/CXR+) and 13 patients (9%) with negative sputum smear/normal chest X-ray (SS-/CXR-). Patients were enrolled from January 1987 to December 1998, and were followed up until December 1999.

RESULTS

On hospital admission the three groups of patients examined did not differ significantly in demographic characteristics, degree of immunosuppression or Mycobacterium tuberculosis drug-susceptibility pattern. SS-/CXR- patients were significantly Less LikeLy to present with prolonged fever and dyspnea. Median survival was shorter for SS-/CXR- patients (6.4 months vs 20.2 and 18.8 months in the other two groups). In multivariate analysis, SS-/CXR-patients had a significantly increased risk of death (hazard ratio 3.0, 95% confidence interval, 1.4 to 6.4, p = 0.004) compared to SS+ patients. This increase in risk was no longer statistically significant when initiation of antituberculous therapy within 8 weeks from the collection date of the first specimen yielding M. tuberculosis was included in the multivariate model.

CONCLUSION

Decreased survival was observed in HIV-infected patients with pulmonary tuberculosis and with both negative sputum smear and normaL chest X-ray presentation. This may primarily be a resuLt of delayed tuberculosis diagnosis and initiation of antituberculous therapy. The latter delay may also lead to a faster progression of HIV infection in SS-/CXR patients, in whom diagnostic oversight may be common.

Prevalence, determinants, and molecular epidemiology of Streptococcus pneumoniae isolates colonizing the nasopharynx of healthy children in Rome

The aim of this study was to determine the factors favouring Streptococcus pneumoniae nasopharyngeal colonization of healthy children attending daycare centres and to describe the circulation of penicillin-nonsusceptible strains using molecular techniques. A single nasopharyngeal swab was obtained from 610 children attending daycare centres in the southeast area of Rome. Streptococcus pneumoniae isolates were serotyped, and antibiotic susceptibility was assayed by the E test. The genetic determinants of erythromycin resistance were detected by a duplex polymerase chain reaction, and the penicillin-nonsusceptible isolates were typed by pulsed-field gel electrophoresis. The overall carriage rate of Streptococcus pneumoniae was 14.9%. Living with more than three persons in the same household was the only risk factor statistically associated with carriage. Sixteen of 85 (18.8%) strains were nonsusceptible to penicillin, and 44 (52%) were resistant to erythromycin. Of the erythromycin-resistant strains, the vast majority showed a high level of resistance and carried the erm(B) gene. The penicillin-nonsusceptible strains belonged to six different serotypes; molecular typing showed that in only one case (2 strains) was there a circulation of the same clone in the same daycare centre. In view of the high rate of resistant Streptococcus pneumoniae strains, risk factors for carriage of resistant strains were evaluated. Children who received macrolides in the previous month had a higher risk of being colonized by macrolide-resistant strains as well as by strains resistant to both penicillin and erythromycin. Limiting the use of antibiotics in children seems the most appropriate measure to control the spread of antibiotic-resistant strains.

Activity of quinupristin-dalfopristin in invasive isolates of Streptococcus pneumoniae from Italy

Eighty-five recent isolates of Streptococcus pneumoniae from patients with invasive disease were examined for their susceptibility to erythromycin, clindamycin, penicillin and quinupristin-dalfopristin by E test. A novel duplex PCR assay was used to detect the presence of the erm(B) or mef(A) genes in all of the erythromycin-resistant isolates. All of the strains tested were susceptible to the combination quinupristin-dalfopristin, regardless of their susceptibility to penicillin or to erythromycin. By duplex PCR, two-thirds of the erythromycin-resistant strains harbored erm, and one-third harbored mef. The activity of quinupristin-dalfopristin was not influenced by the genetic determinant of erythromycin resistance. The in vitro susceptibility of S. pneumoniae to quinupristin-dalfopristin is promising for future use; however, it is important to monitor the possible emergence of resistance.

Expanding drug resistance through integron acquisition by IncFI plasmids of Salmonella enterica Typhimurium

We conducted a 30-year retrospective analysis of IncFI plasmids from Salmonella enterica serotype Typhimurium. These plasmids have been associated with the emergence of epidemic clones of multidrug-resistant Salmonella. Molecular and genetic evidence indicates that IncFI plasmids are evolving through sequential acquisition of integrons carrying different arrays of antibiotic- resistance genes.

[Mycobacterium tuberculosis drug resistance in patients with HIV and pulmonary tuberculosis infections in Rome: 1987-1996]

A retrospective chart review was performed on 118 HIV infected patients with pulmonary tuberculosis hospitalized between 1987 and 1996 in a tertiary care center for Infectious Diseases in Rome. The aims of this study were: a) to evaluate global prevalence of and risk factors for drug-resistant Mycobacterium tuberculosis and multidrug resistant tuberculosis; b) to assess trends in prevalence of drug-resistant tuberculosis over the 10-year study period. Prevalence of drug resistance of first Mycobacterium tuberculosis isolates was tested on Lowenstein-Jensen medium with the proportional method. Of the 118 patients studied, 83 had never been treated for tuberculosis and 35 had already been treated for at least 1 month. The overall prevalence of resistance to one or more drugs was 25% (17% in never treated patients vs 46% in already treated patients; p = 0.002). Five percent of isolates were resistant to both isoniazid and rifampin (1% in never treated patients vs 14% in already treated patients; p = 0.008). Resistance rates to individual drugs were: isoniazid 14%, rifampin 8%, ethambutol 0%, streptomycin 13%. During the study period no significant variations in prevalence of drug-resistant tuberculosis were found. In our area, empiric therapy should include 4 drugs: as well as isoniazid, rifampin and pyrazinamide, we recommend ethambutol. Surveillance of drug-resistant tuberculosis is needed. Directly observed therapy should be considered for HIV patients in order to prevent increases in drug resistance, relapses, and treatment failures.

Pulmonary cryptosporidiosis in patients with acquired immunodeficiency syndrome

Several reports have showed Cryptosporidium species as a cause of intractable diarrhea and malabsorption in patients with acquired immunodeficiency syndrome (HIV). A case of chronic diarrhea in a drug addict woman associated with a symptomatic interstitial pulmonary infection due to Cryptosporidium parvum is described. This unusual C. parvum spread into the bronchial tree is underlined and a survey of the literature is made.

Drug resistance patterns among tuberculosis patients in Rome, 1990-1992

Prevalence of, and risk factors for, drug-resistance of Mycobacterium tuberculosis were assessed among 407 hospitalized patients with tuberculosis in Rome, Italy, during the period 1990-1992. Resistance to 1 or more drugs was detected in 106 isolates (26%). Resistance to streptomycin was the most common (18.4%), followed by isoniazid (10.3%) and rifampin (7.9%). 23 isolates (5.7%) were resistant to both isoniazid and rifampin. Resistance to at least 1 drug and resistance to both isoniazid and rifampin were significantly more common among recurrent cases (40.7% vs. 22.1%, p < 0.001; and 22.1% vs. 1.2%, p < 0.001). Sex, country of origin and HIV infection were not significantly associated with prevalence of drug resistance. Among recurrent cases, prevalence of resistance to at least 1 drug and of resistance to both isoniazid and rifampin, was higher in subjects who had had a previous episode of tuberculosis later than 1969. In the population studied the prevalence of drug-resistant tuberculosis was high, although the risk of initially becoming infected with a multidrug-resistant strain of M. tuberculosis in this area appears to be low. This study suggests the need for enhanced surveillance of drug-resistance of tuberculosis in our country and for implementation of intervention aimed to ensure adequate and complete therapy for patients with tuberculosis.

The efficacy and safety of imipenem/cilastatin in the treatment of severe bacterial infections

We have assessed the efficacy and safety of imipenem/cilastatin in a non-comparative study of 27 immunocompromised patients suffering from severe bacterial infections. Moreover in two groups of 14 patients the efficacy of imipenem/cilastatin versus a standard broad spectrum antibiotic therapy has also been compared. Clinical and microbiological efficacy and side effects have been evaluated.

[Piperacillin in the therapy of severe bacterial infections: comparison of its efficacy and tolerance vs. ceftazidime]

38 patients with severe acute bacterial systemic infections have been enrolled in this study: 19 patients were treated with piperacillin (100-200 mg/kg/day) and 19 with ceftazidime (45-90 mg/kg/day) by i.v. route. In both groups monotherapy has been found effective and well tolerated. Serious side-effects have not been observed. The high cure and eradication rates in both groups do not show statistically significant differences (chi 2 = 0.620 and chi 2 = 0.219, respectively, p greater than 0.05).

[Cefotetan vs ceftriaxone: clinical and bacteriological efficacy in complicated forms of urinary tract infection]

Forty adult patients with UTI complicated by local and/or general diseases have been treated, 20 with Cefotetan and 20 with Ceftriaxone. Both treatments showed good clinical and bacteriological efficacy, with no statistically significant differences between the results. Cefotetan and Ceftriaxone were both well tolerated, without any local or systemic side effects.