Comparing Two Automated Techniques for the Primary Screening-Out of Urine Culture.

Urinary tract infection is the most common human infection with a high morbidity. In primary care and hospital services, conventional urine culture is a key part of infection diagnosis but results take at least 24 h. Therefore, a rapid and reliable screening method is still needed to discard negative samples as quickly as possible and to reduce the laboratory workload. In this aspect, this study aims to compare the diagnostic performance between Sysmex UF-1000i and FUS200 systems in comparison to urine culture as the gold standard. From March to June 2016, 1,220 urine samples collected at the clinical microbiology laboratory of the "Miguel Servet" hospital were studied in parallel with both analysers, and some technical features were evaluated to select the ideal equipment. The most balanced cut-off values taking into account bacteria or leukocyte counts were 138 bacteria/µL or 119.8 leukocyte/µL for the UF-1000i (95.3% SE and 70.4% SP), and 5.7 bacteria/µL or 4.3 leukocyte/µL for the FUS200 (95.8% SE and 44.4% SP). The reduction of cultured plates was 37.4% with the FUS200 and 58.3% with the UF-1000i. This study shows that both techniques improve the workflow in the laboratory, but the UF-1000i has the highest specificity at any sensitivity and the FUS200 needs a shorter processing time.

Characterization of a functional NTPDase in the endoplasmic reticulum of rat submandibular salivary gland.

Nucleotidase activity and Ca-uptake were characterized in endoplasmic reticulum (ER) enriched rat submandibular gland (SMG) microsomal preparations. (i) Ca-uptake had characteristics of an ER Ca-ATPase. (ii) Nucleotidase activity was equally stimulated by calcium, magnesium and manganese, but with different Km values. (iii) Specific inhibitors of P-type Ca-ATPases were ineffective on nucleotidase activity, demonstrating that this activity was not related to calcium uptake and did not correspond to classical Ca(2+) pumps. (iv) ATP and UTP were more efficient substrates, whereas ADP and UDP were hydrolyzed at significantly slower rate. (v) Nucleotidase activity was sensitive to mild detergent solubilization and insensitive to ionophore addition. (vi) Nucleotidase activity was strongly inhibited by suramin, a nucleoside triphosphate diphosphohydrolase (NTPDase) inhibitor. (vii) Nucleotidase activity exponentially diminished as function of time. All these observations are consistent with a NTPDase identity. The presence of a NTPDase was demonstrated by immunohistochemistry in rat SMG. Immunoreactivity was stronger in ductal cells than in mucous and serous acini. Although this enzyme was observed in the plasma membrane, colocalization with the ER marker calnexin revealed a specific subcellular localization in this organelle of all three types of cell. The putative function of this NTPDase activity in salivary glands is discussed.

Lithium and KB-R7943 effects on mechanics and energetics of rat heart muscle.

The role of calcium influx on energy expenditure during cardiac contraction was studied. For this purpose, the described ability of lithium and KB-R 7943 (KBR) to diminish Ca entry through Na-Ca exchanger (Ponce-Hornos & Langer, J Mol Cell Cardiol 1980, 12, 1367, Satoh et al., Circulation 2000, 101, 1441) were used. In isolated contractions (contractions elicited after at least 5 min of rest) LiCl 45 mmol L(-1) decreased pressure developed and pressure-time integral from 42.3 +/- 2.7 and 14.5 +/- 1.2 to 32.1 +/- 3.4 mN mm(-2) and 8.3 +/- 0.9 mN mm(-2) s, respectively. A similar effect was observed in regular contractions (at 0.16 Hz stimulation). The presence of KBR (5 micromol L(-1)) in the perfusate induced a slight but not significant decrease in pressure developed and pressure-time integral in steady-state contractions. As it was previously described, the heat involved in a heart muscle contraction can be decomposed into several components (H1, H2, H3 and H4), but only one (H3) was associated with force generation. While H3 decreased with lithium in both types of contractions, H3/PtI ratio remained unaltered, indicating that the economy for pressure maintenance was unaffected. To further investigate the role of Ca entry on force development, a condition in which the contraction is mainly dependent on extracellular calcium was studied. An 'extra' stimulus applied 200 ms after the regular one in a muscle stimulated at 0.16 Hz induces a contraction with this characteristic (Marengo et al., Am J Physiol 1999, 276, H309). Lithium induced a strong decrease in pressure-time integral and H3 associated with this contraction (43 and 45%, respectively) with no change in H3/PtI ratio. Lithium also reduced (53%) an energy component (H2) associated with Ca cycling. The use of KBR showed qualitatively similar results [i.e. a 33% reduction in pressure-time integral associated with the extrasystole (ES) with no changes in H3/PtI ratio and a 30% reduction in the H2 component]. Li and KBR effects appear to be additive and in the presence of 45 mmol L(-1) Li and 5 micromol L(-1) KBR the extrasystole was abolished in 77%. Lithium and KBR effects particularly for the extrasystole can be explained through the inhibition of Ca entry via Na-Ca exchange giving support to the participation of the Na-Ca exchanger in the Ca influx from the extracellular space. In addition, the results also suggest the possibility of an effect of Li on an additional Ca sensitive locus (different than the Na-Ca exchanger). In this connection, in isolated contractions lithium decreased the energy release fraction related to mitochondrial processes (H4) increasing the economy of the overall cardiac contraction.

[Resistance to penicillin and other antimicrobials in 301 clinical isolates of Streptococcus pneumoniae]. / Resistencia a penicilina y otros antimicrobianos en 301 aislamientos clínicos de Streptococcus pneumoniae.

BACKGROUND: The aim of this study was to assess the susceptibility to penicillin of Streptococcus pneumoniae clinical strains and to analyze the association between penicillin resistance and cefotaxime and cefixime activity in S. pneumoniae isolates with decreased sensitivity to penicillin. METHODS: 301 S. pneumoniae clinical strains were isolated from patients during 1995-1996. Susceptibility to penicillin, cefotaxime, cefepime, erythromycin, chloramphenicol, tetracycline, cotrimoxazole and ciprofloxacin were studied. RESULTS: 38.2% isolates were penicillin-susceptible and 61.8% were penicillin-resistant; 20.6% showed high-level resistance. Resistance rates to erythromycin, chloramphenicol, tetracycline, cotrimoxazole and ciprofloxacin were, respectively, 30.9, 30.2, 40.9, 66.4, and 13.3% overall, and 54.8, 54.8, 61.3, and 93.5% in the 62 strains with high-level resistance to penicillin. Strains resistant to cefotaxime and cefepime were 13.9 and 14.9%, respectively. MIC50 and MIC90 for cefotaxime and cefepime in penicillin-resistant strains were 0.5 and 1 mg/ml. CONCLUSIONS: A high proportion of S. pneumoniae isolates showed resistance to penicillin, in agreement with other Spanish reports. Moreover, resistance to penicillin was significantly associated (p < 0.001) with resistance to erythromycin, chloramphenicol, tetracycline and cotrimoxazole, but not with ciprofloxacin. MIC50 and MIC90 for cefotaxime and cefepime were similar, and lower than those for penicillin in penicillin-resistant pneumococci strains.

In vitro activity of cefepime and cefotaxime compared to six other agents against 350 penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae.

From January 1996 to December 1997, we evaluated the in vitro activity of 8 antimicrobials (penicillin, amoxycillin, amoxycillin/clavulanate, cefuroxime, ceftazidime, cefepime, cefotaxime, and imipenem) against 350 Streptococcus pneumoniae clinical isolates collected from two hospitals. Imipenem, cefepime and cefotaxime were the most active antibiotics against penicillin-intermediate (PI) and highly penicillin-resistant (PR) S. pneumoniae with MICs 2- to 8-fold lower than penicillin. Against PI and PR pneumococci amoxycillin and amoxycillin/clavulanate were 2-times less active than cefepime and cefotaxime, while cefuroxime was 4-8-times less active. The majority of strains of serotypes 6B, 23F, 14, 9 and 19 were penicillin-resistant, both intermediate (68%) and highly resistant (32%).