[Uncomplicated urinary tract infections. Antimicrobial susceptibility study in Navarre]

BACKGROUND

Urinary tract infection (UTI) is a high prevalence infection at the community level. In order to improve the adequacy of the empirical therapy, we evaluated the etiology and the resistance pattern of the main uropathogens responsible for community acquired UTI in Navarre.

METHODS

Retrospective study (2014-2016) in which we included microorganisms recovered with significant counts from samples of patients with community-acquired UTI. The global etiology and etiology according to age and sex was analyzed. Antimicrobial resistance was studied with urotopathogens isolated in 2016.

RESULTS

Escherichia coli was the most frequently isolated microorganism both in the population (60.8%) and in each of the groups analyzed according to age and sex. The sensitivity of E. coli was: nitrofurantoin 97.4%, fosfomycin 96.5% amoxicillin-clavulanic acid 83.8%, trimethoprim-sulfamethoxazole 68.3%, quinolones 63.4% and amoxicillin 41.9%. Pooled sensitivity shows that the sensitivity to fosfomycin was 83.4% in men <15 years, 89.4% in women <15 years and 81.9% in women between 15-65 years; and to nitrofurantoin was 86.7% in women <15 years and 82.2% in women between 15-65 years.

CONCLUSIONS

E. coli continues to be the most frequent microorganism in community-acquired UTI with a rate of sensitivity to fosfomycin and nitrofurantoin above 95%. The empirical treatment of UTI in our environment should not include amoxicillin, amoxicillin-clavulanic acid, trimethoprim-sulfamethoxazole or quinolones. Fosfomycin may be empirically used in the treatment of uncomplicated cystitis in men younger than 15 years and in women under 65 years, and nitrofurantoin may be used empirically in women under 65 years.

[Comparative study of HIV-1/2 antibody confirmatory assay: Geenius™ versus INNO-LIA™]

OBJECTIVE

The aim of the study is to compare two confirmatory tests for HIV-1/2 infection.

METHODS

A prospective study was carried out between 01/01/2015 and 12/31/2015. Serum samples with repeatedly positive results in the Antibody-Antigen-HIV-1/2 (Architect, Abbott) screening assay were included. The serum samples corresponding to new diagnosed cases were selected and were used to compare the two confirmatory assays: Geenius™ HIV-1/2 (Bio-Rad) and INNO-LIA™ HIV-1/2 score line-immunoassay (Innogene-tics®). The HIV-1 viral load (Cobas® AmpliPrepHIV, Ro-che) was performed in discordant or indeterminate cases.

RESULTS

Eight five samples were included. The results of both confirmatory assays were concordant in 80/85 samples: 53 HIV-1, 1 HIV-2, 25 negative and one indeterminate. Cohen's Kappa concordance coefficient between Geenius™ and INNO-LIA™ techniques was very high (0.878).

CONCLUSIONS

The concordance between the two assays is high. The procedure for Geenius™ is simple and fast. Geenius™ is a good alternative to include in the HIV-1/2 diagnostic algorithm.

Vaccine effectiveness in preventing laboratory-confirmed influenza in Navarre, Spain: 2013/14 mid-season analysis

We estimate mid-2013/14 season vaccine effectiveness (VE) of the influenza trivalent vaccine in Navarre, Spain. Influenza-like illness cases attended in hospital (n=431) and primary healthcare (n=344) were included. The overall adjusted VE in preventing laboratory-confirmed influenza was 24% (95% CI: -14 to 50). The VE was 40% (95% CI: -12 to 68) against influenza A(H1)pdm09 and 13% (95% CI: -36 to 45) against influenza A(H3). These results suggest a moderate preventive effect against influenza A(H1)pdm09 and low protection against influenza A(H3).

[Loa Loa and Mansonella perstans coinfection in a patient from Guinea]

We present a case of mixed infection by two filariae (Loa loa and Mansonella perstans). It seems that the infection was suspected due to a pronounced eosinophilia in a routine analysis. Sheathed and unsheathed microfilariae were observed in the spread of peripheral blood, which enabled a diagnosis to be established of mixed infection by filariae. The definitive diagnosis of the species was carried out at the National Centre of Microbiolgy of Majadahonda. A treatment was initiated with dietilcarbamazina and mebendazole which resulted in the patient's being cured and in the elimination of the microfilariae in the patient's blood. Filariasis is still endemic in many countries. Due to the increase of travellers to such zones and the migratory movements from such areas it is not unusual for us to come across such a diagnosis. The implantation of massive treatments against filariae in endemic zones by the World Health Organisation is reducing their transmission and is managing to eliminate the disease in some areas.

[Clinical relevance of nontuberculous mycobacteria]

BACKGROUND

The isolation of nontuberculous mycobacteria (NTM) has increased in recent years largely due to the use of liquid cultivation media. In many cases such isolations lack clinical relevance, which is why the evaluation of their meaning must be carried out on the basis of international clinical criteria. This article studies the impact of using the criteria that the American Thoracic Society (ATS) has established for differentiating an infection of NTM colonisation in respiratory samples.

METHODS

Microbiological and clinical study of the patients with repeated isolations of NTM in respiratory samples registered in our laboratory between 2000 and 2004.

RESULTS

One hundred and sixteen positive cultivations of NTM were obtained, repeatedly isolated in 46 episodes corresponding to 42 patients. Eleven different species were identified: M. xenopi (16 cases), M. avium (12), M. kansasii (7), M. fortuitum (5), M. malmoense (2) and, finally, 1 of each of the following: M. genavense, M. simiae, M. gordonae and M. lentiflavum. It was possible to study 36 patients, of whom 17 met the criteria of the ATS, and, out of these, only 12 received specific treatment. In those cases that did not meet the ATS criteria the isolations did not have any clinical repercussion. In both the treated and untreated groups a clearly differentiated evolution was not observed.

CONCLUSIONS

Facing the difficulty of attributing an etiological role to an NTM of respiratory samples, it is necessary to follow international criteria such as those of the ATS before beginning a specific treatment in order to avoid the incorrect treatment of patients.

Valoración de la prueba de amplificación MTD-2 para la detección directa de Mycobacterium tuberculosis en la muestra

BACKGROUND

To evaluate the utility of the Amplified Mycobacterium Tuberculosis Direct Test (MTD-2, Gen-Probe) in the microbiological diagnosis of tuberculosis.

METHODS

We evaluated the results obtained in 146 specimens with the MTD-2 test, together with those of the culture and smears. The MTD-2 test was performed on all the smear positives specimens (n=47), on the smear-negative specimens, when the test was demanded (n=19), and in other smear-negative specimens previously selected, according to the clinical history of the patient (n=80). We considered real cases of tuberculosis, those that were culture positive for Mycobacterium tuberculosis and those that were specifically treated.

RESULTS

The overall sensitivity, specificity, positive and negative predictive values for the MTD test were: 95, 76, 71, and 96%, for the culture; and 84, 100, 100 and 90% and 75, 94, 89 and 86% for the smears, respectively. In smear positive specimens, the test showed a great specificity, and differentiated M. tuberculosis from other mycobacteria. In the smear negatives, the sensitivity of the test was low and so was the positive predictive value, especially in series performed with a high work load.

CONCLUSIONS

Data from our study show that the MTD-2 test is a reliable method for rapid diagnosis of tuberculosis in smear positive specimens. However, due to its low sensitivity and positive predictive value, it is not recommended in the routine diagnosis of tuberculosis. Also, for this reason, whenever a positive result is obtained with a smear negative specimen, the result needs to be confirmed with another specimen.

Estudio de la resistencia de Mycobacterium tuberculosis a los principales tuberculostáticos (Hospital de Navarra 1996-2003)

INTRODUCTION

The aim of this study was to evaluate the sensitivity to the principal tuberculostatics of the M. tuberculosis stocks isolated in our laboratory and to study the factors related to resistance.

METHODS

Study of 475 stocks of M. tuberculosis corresponding to all cases diagnosed in the eight year period between 1996 and 2003. We employed the BACTEC 460TB system, together with Lowenstein solid medium, in the cultivation of the samples. The sensitivity studies were carried out using the BACTEC 460TB system.

RESULTS AND CONCLUSIONS

Both the incidence and the number of cases of resistant tuberculosis showed oscillations over the eight years of the study. The fact that there is no homogeneous tendency makes it necessary to maintain active surveillance of this process. Global resistance to isoniacide was 8%, making it is convenient to carry out sensitivity studies in all the diagnosed cases. The cases of multiresistant tuberculosis (resistant to at least isoniacide and rifampicin), did not exceed 3%. The prognosis of the patients with resistant tuberculosis was bleak in cases of coinfection with HIV; however, when the immunological defences were conserved, and guidelines for treatment with active drugs were provided, the recovery of the majority of the patients was achieved. At present, sensitive and rapid procedures are available to us, making it recommendable to study the sensitivity of all the stocks of M. tuberculosis that are isolated; this is essential in the case of HIV positive or immigrant patients.

Bacteriemia y absceso hepático causado por Yersinia enterocolitica

Yersinia enterocolitica is a Gram-negative coccobacillus that is distributed world-wide and whose natural reservoir is found in a great variety of animals. Transmission to humans mainly occurs through the faecal-oral path although cases have been described of transmission through blood transfusions. It is isolated within a gastro-intestinal clinical picture and it rarely produces extra-intestinal disorders such as bacteraemia, abscesses, cutaneous signs, etc. The latter have been associated with different underlying diseases such as alterations of the iron metabolism, diabetes mellitus, alcoholism, malnutrition, tumours, immunosuppressant therapy and cirrhosis. We present the case of a diabetic patient who developed bacteraemia associated with hepatic abscess due to Yersinia enterocolitica.

Situación de Staphylococcus aureus resistente a meticilina en el Hospital de Navarra (2000-2002)

BACKGROUND

The aim of the present paper was to determine the prevalence and characteristics shown by isolations of Methicillin Resistant Staphylococcus Aureus, isolated in our Microbiology Service.

METHODS

Retrospective study, covering the years 2000, 2001 and 2002. Analysis was made of the origin of the infection (nosocomial or non-nosocomial), the unit of origin in the event of nosocomial origin, anatomical localisation of the sample, and pattern of antibiotic sensitivity.

RESULTS

The isolations of Methicillin Resistant Staphylococcus aureus accounted for 7.88% of the Staphylococcus aureus isolated. Less than half of the strains (44.87%) had a nosocomial origin and were most often isolated in the exudates of wounds. With respect to the pattern of resistance, there was some 50% of resistance to erythromycin, some 43.60% to clindamycine and some 21.79% to mupirocin.

CONCLUSIONS

The prevalence and resistance pattern in vitro of the isolations of Methicillin Resistant Staphylococcus Aureus in our hospital are lower than that published in other areas of Spain.

[Spontaneous bacterial peritonitis and bacteraemia due to Aeromonas hydrophila]

Bacterial peritonitis is a frequent complication in cirrhotic patients. Amongst the aetiological germs, Aeromonas is very infrequent. We present the clinical case of a cirrhotic patient with peritonitis and bacteraemia due to Aeromonas hydrophila. This micro-organism is a Gram-negative bacillus of the Vibrionaceae family. It very frequently produces gastroenteritis in the human being. Exceptionally it can give rise to extraintestinal infections, especially in immunodepressed patients. Peritonitis due to Aeromonas has been described in association with spontaneous bacterial peritonitis in cirrhotic patients, in patients on peritoneal dialysis and in cases of peritonitis secondary to intestinal perforation.

[Resistance to penicillin and other antimicrobials in 103 clinical isolations of Streptococcus pneumoniae (2000-2001)]

BACKGROUND

To determine in our hospital the sensitivity of isolations of Streptococcus pneumoniae to penicillin, as well as to analyse the association of resistance to penicillin and other antimicrobials and the activity of cefotaxime and cefepime in pencillin resistant strains of Streptococcus pneumoniae.

METHODS

The sensitivity was determined on 103 isolations of Streptococcus pneumoniae, from clinical samples from the years 2000-2001, to penicillin, eritromycine, cloramfenicol, tetracycline, cotrimoxazol, cefotaxime, cefepime and levofloxacine.

RESULTS

Sixty-eight percent of the isolations were sensitive to penicillin, while some 32% of the isolated strains of Streptococcus pneumoniae were penicillin resistant, with 7.7% showing a high degree of resistance. Resistance to eritromycine, cloramfenicol, tetracycline, cotrimoxazol and levofloxacine was 38.8%; 9.7%; 20.4%; 25.2% and 2.9% respectively, increasing to values of 66.6%; 30.3%; 48.5%; 72.7% and 9.1% in the 33 penicillin resistant strains. Resistance to cefotaxime and cefepime was 9.7% and 10.6% respectively. CONCLUSIONS. A high percentage of strains of Streptococcus pneumoniae show some degree of resistance to penicillin, but with lower figures than in other studies carried out at a national level. Similarly, it was demonstrated that resistance to penicillin is significantly associated (p < 0.001) with resistance to all the antimicrobials studied, except for levofloxacine. The resistances to cefotaxime and cefepime were comparable, with less activity being observed in these when facing penicillin resistant strains of Streptococcus pneumoniae.