Novel mechanisms of resistance to ß-lactam antibiotics in Haemophilus parainfluenzae: ß-lactamase-negative ampicillin resistance and inhibitor-resistant TEM ß-lactamases.

OBJECTIVES: To determine the mechanisms of resistance to ß-lactam antibiotics in clinical isolates of Haemophilus parainfluenzae. METHODS: Twenty clinical isolates of H. parainfluenzae with decreased susceptibility to aminopenicillins were examined and compared with a control group of 20 fully susceptible isolates. In this collection, the presence of amino acid substitutions in the transpeptidase domain of penicillin-binding protein 3 (PBP3), ß-lactamase production and the surrounding genetic regions of blaTEM genes in selected isolates were analysed. RESULTS: Of the 20 non-susceptible isolates, 8 produced TEM ß-lactamase (gBLPAR), 7 had mutations in the transpeptidase domain of the ftsI gene related to decreased susceptibility to ß-lactams (gBLNAR) and 5 had both resistance mechanisms (gBLPACR). No resistance mechanisms were identified in the susceptible control group (gBLNAS). gBLNAR isolates had MIC90 values 4- to 16-fold higher than gBLNAS isolates for ampicillin, amoxicillin/clavulanic acid, cefuroxime, cefotaxime and cefixime, and the most common PBP3 mutation was Asn526Ser. The additional Ser385Thr substitution (III-like group) may confer decreased susceptibility to cefotaxime, cefixime and aztreonam, as in Haemophilus influenzae. In two ß-lactamase-positive isolates without PBP3 mutations, the inhibitor-resistant TEM (IRT) ß-lactamases TEM-34 and the novel TEM-182 were detected and carried by a TnA transposon of the Tn2 type; both isolates had an amoxicillin/clavulanic acid MIC of ≥8 mg/L. The TnA transposons of two ß-lactamase-positive isolates (TEM-1 and TEM-182) were inserted between the tfc20 and tfc21 genes, typically associated with integrative and conjugative elements in Haemophilus spp.; the TEM-34 IRT ß-lactamase was harboured in a ∼5.5 kb plasmid. CONCLUSIONS: Clinical isolates of H. parainfluenzae express a variety of aminopenicillin resistance mechanisms, either alone or in combination, including PBP3 modifications, blaTEM-1 and IRT ß-lactamase production.

Activity of ertapenem and other antimicrobials against ESBL-producing enterobacteria isolated from urine in patients from Madrid.

The objective of this study was to evaluate the activity of ertapenem and other antimicrobials against extended-spectrum beta-lactamase (ESBL)-producing enterobacteria isolated from patients' urine samples at 4 community healthcare centers in the Madrid (Spain) area and to determine the prevalence of ESBL-producing enterobacteria in community-acquired urinary tract infections. The antibiotic susceptibility results were compared by patient age and sex. A total of 293 strains were studied. The minimum inhibitory concentration (MIC) for each antibiotic was determined using the agar dilution method. The tested carbapenems were the antibiotics with the greatest activity (ertapenem MIC(90)=0.06 mg/l; imipenem MIC(90)=0.5 mg/l), with no intermediate or resistant strains being observed. High rates of resistance to ciprofloxacin (80.9%) and cotrimoxazole were observed (62.1%). The global prevalence of ESBL-producing enterobacteria was 3.6% (293/8,139). Prevalence according to areas was 5.3% in Getafe, 3.45% in Arguelles, 3.02% in Alcala de Henares and 3.56% in Mostoles. The global prevalence of ESBL-producing Escherichia coli was 4.15% (279/6,721). The analysis of resistance according to patient sex (males versus females) showed no significant differences. The analysis of resistance according to patient age (<50 years versus > or = 50 years) showed statistically significant differences (more resistance among subjects > or = 50 years old) for cotrimoxazole (OR=0.43, 95%CI: 0.20-0.93, p=0.018) and ciprofloxacin (OR=0.32, 95%CI: 0.14-0.74, p=0.0027). In view of the good activity shown by ertapenem, and the continuous increase in the prevalence of ESBL strains, this antibiotic and some of the others could be a good choice for the treatment of community-acquired urinary tract infections produced by such bacteria in Spain.

Clinical presentation of candidaemia in elderly patients: experience in a single institution.

OBJECTIVE: To analyse the clinical presentation of candidaemia in elderly patients. METHODS: A comparison of clinical presentation of candidaemia cases was carried out in a Spanish tertiary hospital between January 2010 and September 2015. RESULTS: Forty-five cases (32%) corresponded to elderly patients (≥ 75 years) and 95 cases (68%) to non-elderly patients (16-74 years). A higher proportion of elderly patients presented solid tumour (51% versus 32%, p=0.026) and a lower proportion had undergone solid or hematopoietic transplantation (0% versus 28%, p<0.001). Fewer elderly patients (16 patients, 36%) had a central venous line inserted than non-elderly patients (81 patients, 85%, p<0.001). Isolation of Candida parapsilosis was significantly lower among elderly (13.3%) than among non-elderly patients (32%, p=0.015). Fundoscopy was carried out in 20 elderly (44%) and in 64 younger patients (67%, p=0.009). The proportion of patients who underwent echocardiography was similar in both groups (56% vs 66%, respectively; p=0.218). Adequate antifungal treatment within the first 48 hours was administered in16 elderly patients (36%) and 58 younger patients (61%, p=0.005). Catheter removal was carried out in 9 elderly patients (68.1%) and in 40 non-elderly patients (49%, p=0.544). Mortality was higher among elderly patients (55.6%) than non-elderly patients (36.8%; p=0.037). CONCLUSIONS: Elderly patients account for a substantial proportion of patients suffering from candidaemia in recent years. The clinical management of these patients was less appropriate than in younger patients with respect to fundus examination and the prescription of appropriate antifungal treatment. Mortality in elderly patients was higher than in younger patients.

Safety of vemurafenib in patients with BRAF V600 mutated metastatic melanoma: the Spanish experience.

OBJECTIVES: Vemurafenib tolerability was assessed in a large, open-label, multicentre study in patients with BRAF V600 mutated advanced melanoma. We investigated safety, tolerability and efficacy of vemurafenib in Spanish patients participating in that study. METHODS: Patients with previously treated or treatment-naive, unresectable stage IIIC or stage IV, BRAF V600 mutation-positive melanoma received vemurafenib 960 mg twice daily until disease progression, unacceptable toxicity, withdrawal of consent or death. The primary endpoint was safety; secondary endpoints included overall response rate (ORR), progression-free survival (PFS) and overall survival (OS). RESULTS: 301 Spanish patients were included, 70 % with M1c disease, 22 % with brain metastases and 51 % with prior systemic therapy for metastatic disease. Most frequent adverse events included fatigue (48 %), arthralgia (45 %), rash (41 %), photosensitivity (34 %) and skin neoplasms (21 %). Grade 3/4 adverse events occurred in 156 patients (52 %), including cutaneous squamous cell carcinoma (including keratoacanthoma; 16 %), fatigue (6 %) and arthralgia (5 %). The ORR was 28 % (95 % CI 23-34 %). Responses occurred in patients with brain metastases (18 %), elevated baseline lactate dehydrogenase (19 %) and poor performance status (15 %), and elderly patients (22 %). Median PFS was 5.8 (95 % CI 5.0-6.4) months; median OS was 10.5 (95 % CI 9.5-13.5) months. CONCLUSION: Our results for Spanish patients in the vemurafenib safety study indicate similar efficacy and a comparable safety profile in Spanish patients with no new safety signals compared with the overall population. Clinical benefit was demonstrated in poor-prognosis patients and in those with favourable baseline characteristics, suggesting that poor-prognosis patients may also benefit from vemurafenib treatment.

A phase II study of feasibility and toxicity of bevacizumab in combination with temozolomide in patients with recurrent glioblastoma.

PURPOSE: The aim of this prospective and multicentric phase II study was to evaluate the efficacy and safety of temozolomide (TMZ) and bevacizumab (BV) in patients (pts) with recurrent glioblastoma (GB), previously treated with chemoradiotherapy and at least three cycles of adjuvant TMZ. PATIENTS AND METHODS: Patients with GB at first relapse received BV 10 mg/kg day every 2 weeks and TMZ 150 mg/m(2) days 1-7 and 15-21, every 28 days. Patients underwent brain magnetic resonance imaging every 8 weeks. RESULTS: Thirty-two evaluable pts were recruited in 8 sites. Fourteen pts (44%) had gross total resection. O(6)-methylguanine-DNA methyltransferase (MGMT) promoter was methylated in 12 pts, unmethylated in 6 pts, and missing in 14 pts. The estimated 6-month progression free survival (PFS) rate was 21.9% (95% CI 9.3-40.0%). The median PFS and overall survival (OS) were 4.2 months (95% CI 3.6-5.4 months) and 7.3 months (95% CI 5.8-8.8 months), respectively. No significant association with MGMT status was found in terms of OS or PFS. Six of 32 pts (19%; 95% CI 7.2-36.4) were long-term survivors, with a median PFS and OS (50% events) of 9.5 months (95% CI 7.9-23.6) and 15.4 (95% CI 8.9-NA), respectively: no differences in baseline characteristics were identified in comparison with total population. No unexpected toxicities or treatment-related deaths were observed. CONCLUSIONS: This regimen showed to be feasible and well tolerated in pts with recurrent GB pretreated with TMZ. Further investigation is warranted to identify subpopulations that are more likely to benefit from addition of BV to GB therapy.

Erythromycin resistance of Streptococcus pyogenes in Madrid.

BACKGROUND: Erythromycin is considered to be an adequate alternative to penicillin for patients who are allergic to penicillin. Erythromycin-resistant Streptococcus pyogenes strains have been reported in some parts of the world. METHOD: The in vitro activity of erythromycin and other antimicrobial agents was determined in a total of 1310 clinical Streptococcus pyogenes isolates collected in the city of Madrid from January, 1993, through December, 1996. RESULTS: All strains showed susceptibility to penicillin, rifampin, vancomycin and chloramphenicol. Tetracycline resistance was 8.5%. In 36 of the strains (2.7%) MIC was 4 microg/ml for ofloxacin. Clindamycin resistance was observed in only 18 strains (1.4%); this resistance was constitutive in 15 and inducible in 3 strains. Resistance to erythromycin was observed in 14.3% of the strains, showing an increase during the study period (2.0% in 1993 vs. 22.4% in 1996; chi square for linear trend 68.8, P < 0,0001); >90% of them showed the novel resistance phenotype described by Seppälä et al. and 32 of 32 of these strains showed by PCR the 1.4-kb fragment of the mefA gene recently described as the novel macrolide efflux resistance determinant. The erythromycin-resistant strains were isolated more often in pediatric patients (144 of 872) than in adults (44 of 438) (chi square 9.9, P = 0.0016). CONCLUSION: The study emphasizes the need to screen for resistance to macrolides in S. pyogenes and indicates that resistance to erythromycin in S. pyogenes has increased significantly in Madrid.

Primary meningococcal conjunctivitis.

Neisseria meningitidis is an uncommon cause of acute bacterial conjunctivitis. One case of primary meningococcal conjunctivitis in a healthy 6-year-old boy is reported. The patient was initially treated with a topical instillation of polymyxin B, neomycin and gramicidin in ophthalmic solution, and this was followed by systemic rifampin once the diagnosis had been established. No ocular or systemic complications developed.

Sexual responses to intrauterine stress: body and brain growth.

The aims of this work were to analyse body and brain growth as produced by deficiencies in the uteroplacental blood supply, and to evaluate sexual responses to intrauterine stress. Intrauterine growth retardation (IUGR) was experimentally induced in pregnant rats by partial obstruction in both uterine vessels at 1,7 and 14 gestational days. The dysfunctions in the placental circulation retarded both somatic and cerebral growth, depending on the period of gestational stress and the sex. Brain weight had a relatively greater resistance than body weight, which is called a "brain sparing" mechanism. The body and brain sexual dimorphism in control pups was inhibited in IUGR pups. This study shows that prenatal stress exposition might modify growth and sexual dimorphism at birth.

Skeletal maturation in intrauterine growth-retarded rats treated with growth hormone.

The objective of this study was to analyse the effects of intrauterine growth retardation (IUGR) and growth hormone (Gh) therapy on skeletal maturation in growth retarded rats. One-hundred and thirty-five rats constituted the groups: Control (C), Sham-operated (SH), IUGR and IUGR+Gh: injected with Genotropin 3.0 mg/kg/day) from 21 to 60 days of age. SH was injected only with saline solution. The thickness of tibial cartilage was assessed on X-ray at the ages 1, 21, 42, 63 and 84 days and categorised according to three levels. L1: maximal thickness, L2: reduction of 50% and L3: absence. The percentual differences between frequencies for each level were compared and clustered by simple ligation in Euclidean distance. The results lead to us to conclude that skeletal maturation does not appear to be modified by IUGR, while it is accelerated by growth hormone in growth-retarded rats.

Effects of bilateral uterine vessel ligation on skeletal growth in rats.

The aim of the present study was to assess the catch-up growth in the postcranial skeleton of intrauterine growth retarded (IUGR) rats. Male and female Wistar rats were assigned to one of the following groups: controls, sham-operated, IUGR. The IUGR was produced by uterine vessels bending (day 14th of pregnancy). Trunk, pelvis, femur and humerus were measured on Rx of each animal, from I to 84 days of age. Data were processed by repeated analysis of variance and LSD post hoc test. The reduced placental blood flow disturbed the skeletal growth in pups, with the axial skeleton relatively more affected than the bones of the extremities. The catch up only took place in femur length of both sexes. The widths of long bones remained significantly retarded. We concluded that nutritional rehabilitation during the postnatal period might not be enough to allow a complete growth recovery.

Safety of vemurafenib in patients with BRAFV600 mutated metastatic melanoma: the Spanish experience

Objectives. Vemurafenib tolerability was assessed in a large, open-label, multicentre study in patients with BRAFV600 mutated advanced melanoma. We investigated safety, tolerability and efficacy of vemurafenib in Spanish patients participating in that study. Methods. Patients with previously treated or treatment-naive, unresectable stage IIIC or stage IV, BRAFV600 mutation-positive melanoma received vemurafenib 960 mg twice daily until disease progression, unacceptable toxicity, withdrawal of consent or death. The primary endpoint was safety; secondary endpoints included overall response rate (ORR), progression-free survival (PFS) and overall survival (OS). Results. 301 Spanish patients were included, 70 % with M1c disease, 22 % with brain metastases and 51 % with prior systemic therapy for metastatic disease. Most frequent adverse events included fatigue (48 %), arthralgia (45 %), rash (41 %), photosensitivity (34 %) and skin neoplasms (21 %). Grade 3/4 adverse events occurred in 156 patients (52 %), including cutaneous squamous cell carcinoma (including keratoacanthoma; 16 %), fatigue (6 %) and arthralgia (5 %). The ORR was 28 % (95 % CI 23-34 %). Responses occurred in patients with brain metastases (18 %), elevated baseline lactate dehydrogenase (19 %) and poor performance status (15 %), and elderly patients (22 %). Median PFS was 5.8 (95 % CI 5.0-6.4) months; median OS was 10.5 (95 % CI 9.5-13.5) months. Conclusion. Our results for Spanish patients in the vemurafenib safety study indicate similar efficacy and a comparable safety profile in Spanish patients with no new safety signals compared with the overall population. Clinical benefit was demonstrated in poor-prognosis patients and in those with favourable baseline characteristics, suggesting that poor-prognosis patients may also benefit from vemurafenib treatment (AU)

No disponible

A phase II study of feasibility and toxicity of bevacizumab in combination with temozolomide in patients with recurrent glioblastoma

Purpose. The aim of this prospective and multicentric phase II study was to evaluate the efficacy and safety of temozolomide (TMZ) and bevacizumab (BV) in patients (pts) with recurrent glioblastoma (GB), previously treated with chemoradiotherapy and at least three cycles of adjuvant TMZ. Patients and methods. Patients with GB at first relapse received BV 10 mg/kg day every 2 weeks and TMZ 150 mg/m2 days 1–7 and 15–21, every 28 days. Patients underwent brain magnetic resonance imaging every 8 weeks. Results. Thirty-two evaluable pts were recruited in 8 sites. Fourteen pts (44 %) had gross total resection. O6-methylguanine-DNA methyltransferase (MGMT) promoter was methylated in 12 pts, unmethylated in 6 pts, and missing in 14 pts. The estimated 6-month progression free survival (PFS) rate was 21.9 % (95 % CI 9.3–40.0 %). The median PFS and overall survival (OS) were 4.2 months (95 % CI 3.6–5.4 months) and 7.3 months (95 % CI 5.8–8.8 months), respectively. No significant association with MGMT status was found in terms of OS or PFS. Six of 32 pts (19 %; 95 % CI 7.2–36.4) were long-term survivors, with a median PFS and OS (50 % events) of 9.5 months (95 % CI 7.9–23.6) and 15.4 (95 % CI 8.9–NA), respectively: no differences in baseline characteristics were identified in comparison with total population. No unexpected toxicities or treatment-related deaths were observed. Conclusions. This regimen showed to be feasible and well tolerated in pts with recurrent GB pretreated with TMZ. Further investigation is warranted to identify subpopulations that are more likely to benefit from addition of BV to GB therapy (AU)

No disponible

[Antimicrobial resistance of Haemophilus influenzae isolated outside of the hospital]. / Resistencia antimicrobiana de Haemophilus influenzae aislado en el medio extrahospitalario.

A total of 209 H. influenzae strains isolated from follow-up patients were studied. Twenty eight strains were serotype b (13.4%), 82 corresponded to type I of Kilian (39.2%), and 41 produced beta-lactamase (19.6%). Strains were resistant to trimethoprim-sulfamethoxazole (SXT) in 79.9% of cases, to the erythromycin in 18.2%, to tetracycline in 16.7%, to chloramphenicol in 13.8%, and to cefaclor in 0.1% of instances. There were no strains resistant to cefotaxime nor to amoxicillin/clavulanic acid. Resistances to three or more antibiotics were observed in 14.8% of the strains. The most common of these combinations was ampicillin-chloramphenicol-tetracycline SXT (61.3%).

Evaluation of a colour test for rapid detection of Salmonella.

The performance of a colour test (Wellcolex) for rapid detection of the most frequently isolated O serogroups of salmonella (A, B, C, D, E/G) and the Vi antigen was evaluated using colonies grown on enteric differential agar media and in selenite broth. The test had excellent sensitivity (100%) and specificity (100%) with colonies taken directly from primary culture plates. Initial tests in selenite broth showed limited sensitivity (62.1%) but by using high quality media and modifying the inoculation procedure, sensitivity was greatly improved (99%).

[Antibiotic resistance to erythromycin, clindamycin and tetracycline of 573 strains of Streptococcus pyogenes (1992-1994)]. / Resistencia antibiótica a eritromicina, clindamicina y tetraciclina de 573 cepas de streptococcus pyogenes (1992-1994).

BACKGROUND: The aim of this study was to know the antibiotic resistence of Streptococcus pyogenes to erythromycine, clindamycine and/or tetracycline in community samples. The second aim was to determine the existence of multiresistant strains and to know the relationship between resistant strains, clinical samples and age of the patient. METHOD: A retrospective analysis was performed in all the strains of S. pyogenes isolated from January 1992 to December 1994. Antibiotic sensitivity was studied by MIC by the microdilution method using the Pasco semiautomatic system. RESULTS: During the study period 573 beta hemolytic streptococci were identified as S. pyogenes. The global resistance to erythromycine (2.8%), clindamycine (1.4%) and tetracycline (7.3%) remains at low levels but has significantly increased in the case of erythromycine (p < 0.05) and tetracycline (p < 0.05) over these 3 years. The incidence of strains resistant to clindamycine has also increased slowly although this rise is not significant. Five strains (0.9%) were not sensitive to the three antibiotics studied, 4 being isolated in the last trimester of 1994 in pharyngeal exudates. S. pyogenes resistant to erythromycine was most frequently isolated from cutaneous lesions and in pediatric patients (under the age of 14 years). CONCLUSIONS: These results confirm the trend towards an increase in the number of strains of S. pyogenes resistant to erythromycine, clindamycine and/or tetracycline, being most often found in cutaneous lesions and pediatric patients.

Dissemination of emm28 erythromycin-, clindamycin- and bacitracin-resistant Streptococcus pyogenes in Spain.

Reported here is an unusual cluster of non-invasive infections caused by an emm28 Streptococcus pyogenes strain resistant to bacitracin, erythromycin and clindamycin detected in Santander, Spain. Since one of the characteristics of group A streptococci is their almost uniform susceptibility to bacitracin, this finding was unusual, and a search for bacitracin-resistant Streptococcus pyogenes strains was conducted in two other distant cities of Spain (Madrid and San Sebastián) where their presence was confirmed. These strains were frequently associated with erythromycin- and clindamycin-resistance, and most of them belonged to a unique emm28 T28, ST52 clone.