Transferable mechanisms of quinolone resistance are more frequent among enterotoxigenic Escherichia coli isolates displaying low-level quinolone resistance.

This study analysed the mechanisms of quinolone resistance among enterotoxigenic Escherichia coli (ETEC) in a periurban area of Lima, Peru. The susceptibility to nalidixic acid and ciprofloxacin, the role of Phe-Arg-b-Naphtylamyde inhibitable-(PAbN) efflux pumps, the presence of mutations in gyrA and parC as well as the presence of aac(6')Ib-cr, qepA, qnrA, qnrB, qnrC, qnrD, qnrVC and oqxAB were determined in 31 ETEC from previous case/control studies of children's diarrhoea. Discordances between disk diffusion, with all isolates showing intermediate or fully resistance to nalidixic acid, and minimal inhibitory concentration (MIC), with 7 isolates being below considered resistance breakpoint, were observed. Twenty-one isolates possessed gyrA mutations (19 S83L, 2 S83A). AAC(6') Ib-cr, QnrS, QnrB and QepA were found in 7, 6, 2 and 1 isolates respectively, with 3 isolates presenting 2 transferable mechanisms of quinolone resistance (TMQR) concomitantly. TMQR were more frequent among isolates with MIC to nalidixic acid ranging from 2 to 16 mg/L (p=0.03), while gyrA mutations were more frequent among isolates with nalidixic acid MIC >= 128 mg/L (p=0.0002). In summary, the mechanisms of quinolone resistance present in ETEC isolates in Peru have been described. Differences in the prevalence of underlying mechanisms associated with final MIC levels were observed. The results suggest two different evolutive strategies to survive in the presence of quinolones related to specific bacterial genetic background.

Transferable mechanisms of quinolone resistance are more frequent among enterotoxigenic Escherichia coli isolates displaying low-level quinolone resistance

@#This study analysed the mechanisms of quinolone resistance among enterotoxigenic Escherichia coli (ETEC) in a periurban area of Lima, Peru. The susceptibility to nalidixic acid and ciprofloxacin, the role of Phe-Arg-b-Naphtylamyde inhibitable-(PAbN) efflux pumps, the presence of mutations in gyrA and parC as well as the presence of aac(6’)Ib-cr, qepA, qnrA, qnrB, qnrC, qnrD, qnrVC and oqxAB were determined in 31 ETEC from previous case/control studies of children’s diarrhoea. Discordances between disk diffusion, with all isolates showing intermediate or fully resistance to nalidixic acid, and minimal inhibitory concentration (MIC), with 7 isolates being below considered resistance breakpoint, were observed. Twenty-one isolates possessed gyrA mutations (19 S83L, 2 S83A). AAC(6’) Ib-cr, QnrS, QnrB and QepA were found in 7, 6, 2 and 1 isolates respectively, with 3 isolates presenting 2 transferable mechanisms of quinolone resistance (TMQR) concomitantly. TMQR were more frequent among isolates with MIC to nalidixic acid ranging from 2 to 16 mg/L (p=0.03), while gyrA mutations were more frequent among isolates with nalidixic acid MIC > 128 mg/L (p=0.0002). In summary, the mechanisms of quinolone resistance present in ETEC isolates in Peru have been described. Differences in the prevalence of underlying mechanisms associated with final MIC levels were observed. The results suggest two different evolutive strategies to survive in the presence of quinolones related to specific bacterial genetic background.

Relevant role of efflux pumps in high levels of rifaximin resistance in Escherichia coli clinical isolates.

BACKGROUND: Enteropathogens have shown a high level of resistance against commonly used antibacterial drugs in Peru and it is necessary to explore alternative treatments. The aim of this study was to analyse the in vitro activity of rifaximin against diarrhoeagenic and commensal Escherichia coli in children less than 2 years of age. METHODS: The minimal inhibitory concentration (MIC) to rifampicin and rifaximin was determined for 210 strains in the presence and absence of phenyl-arginine-ß-naphthylamide (PAßN) and the mechanisms of resistance were investigated. RESULTS: The MIC levels ranged between 8 and >256 mg/litre and the predominant mechanism of resistance to rifaximin was the efflux pumps inhibited by PAßN in 95.2% of the isolates. CONCLUSIONS: The present MIC values are higher than those observed in other studies. Efflux pumps inhibited by PAßN were the cause of the rifaximin resistance in the majority of cases and suggest the presence of an environmental selective pressure. Consequently, rifaximin should be used with caution in the treatment of diarrhoea in Peru.

Antimicrobial resistance in Shigella spp. causing traveller's diarrhoea (1995-2010): a retrospective analysis.

BACKGROUND: Shigellosis is a global human health problem causing an important morbidity among travellers returning from tropical areas. This study was aimed to describe the evolution of antimicrobial resistance profile in Shigella spp. isolated between the years 1995-2010 in patients with traveller's diarrhoea (TD) returning from tropical areas. METHODS: The levels of antimicrobial resistance were tested in a total of 191 Shigella spp. isolated during the period from 1995 to 2010. RESULTS: A decrease of cases of diarrhoea caused by Shigella has been observed in recent years. A wide spectrum of antibiotic resistance was observed among Shigella spp. These isolates showed high levels of resistance to tetracycline (84%), co-trimoxazole (75.5%), and ampicillin (45.5%). The resistance was low to ciprofloxacin (2.1%), azithromycin (3.9%) and furazolidone (8.4%). According to the period, in the case of ampicillin, amoxicillin plus clavulanic acid, chloramphenicol, values of resistance were significantly decreasing from 1995-2000 to 2001-2010, (62.5% vs. 28.4%, 19.8% vs. 6.6%, 23.4 vs. 10.4%, respectively). Meanwhile in nalidixic acid and tetracycline the evolution of resistance has increased over time. CONCLUSIONS: A decrease in the isolation number of Shigella spp. causing TD has been observed. Differential trends in the evolution of the levels of resistance to the tested antibacterial agents have been observed.

[Impact of digital mammography in the detection and management of microcalcifications]. / Influencia de la mamografía digital en la detección y manejo de microcalcificaciones.

OBJECTIVE: To determine whether the introduction of digital mammography in breast cancer screening has resulted in changes in the detection and management of microcalcifications. MATERIAL AND METHODS: We retrospectively studied the performance indicators of our breast cancer screening program that are related to the diagnosis of microcalcifications (rates of recall and recommendation of intermediate follow-up after screening, rate of indication of invasive procedures for microcalcifications and their positive predictive value, detection rate for microcalcifications, and number of ductal carcinomas in situ (DCIS) diagnosed). We compared the results obtained using direct digital mammography (september 2008-august 2009) with those obtained using analog mammography (September 2006-August 2007). STATISTICAL ANALYSIS: Chi-square test and measures of association. RESULTS: We found that using digital mammography led to significant increases in the recall rate (from 50.8 to 64‰), in the rate of intermediate follow-up after screening (from 9.41 to 18.7‰), in the rate of indication for invasive procedures (from 1.88 to 3.01‰), in the cancers detected through microcalcifications (from 0.86 to 1.36‰), and in the number of DCIS diagnosed. CONCLUSION: Direct digital mammography has improved the detection of microcalcifications, increasing the number of DCIS diagnosed without decreasing the positive predictive value of the invasive procedures indicated for microcalcifications. However, direct digital mammography has had a negative effect by increasing the recall rate and indication for short-term follow-up, possibly due to the difficulty of comparing the findings with those of earlier analog mammograms.

Acute phase is the only significantly reduced component of the injury response after laparoscopic cholecystectomy.

The objective demonstration of improved postoperative recovery suggests that the surgical injury response induced by the laparoscopic approach is less intensive than that after open surgery. Twenty-five patients diagnosed as having noncomplicated gallstones were studied prospectively. They were operated by laparoscopy (group I, n = 12) or open surgery (group II, n = 13). Analgesia requirements (p < 0.026) and postoperative stay (p < 0.001) were significantly less in group 1. Cholecystectomy performed by either technical options induced a significant increase over basal values of glucose, lactate, white blood cell count, prolactin, ACTH, cortisol, interleukin 6, C-reactive protein, and PCO2. Both surgical procedures induced a significant reduction of total proteins, albumin, prealbumin, free fatty acids hemoglobin, hematocrit, and pH. There were no differences between the levels of growth hormone, insulin, glucagon, or PO2 during any of the periods studied. Comparison of the results of the two cholecystectomy techniques showed that laparoscopic cholecystectomy induced a significantly less intensive acute-phase response (area under the curve) of interleukin 6 (17 +/- 17 versus 47 +/- 26 pg/ml x hr x 10(2); p < 0.003), C-reactive protein (16 +/- 12 versus 35 +/-16 mg/dl x hr x 10; p < 0.004), and prealbumin (16 +/- 2.7 versus 13.8 +/- 2.3 mg/dl x hr x 10(2); p < 0.05). The surgical injury response after laparoscopic cholecystectomy is similar to that after open cholecystectomy, but the aeute-phase response component is less intense. This finding may be a consequence of the reduced size of the operative wound with laparoscopic cholecystectomy.

[Screening for glaucoma in diabetic patients by using the Schiörtz tonometer]. / Cribado del glaucoma en pacientes diabéticos mediante el tonómetro de Schiörtz.

OBJECTIVES: To assess the usefulness of measuring in primary care the intraocular pressure (IOP) of diabetics as a glaucoma screening test, validating the Schiörtz tonometer for this end. To analyse the prevalence of glaucoma and associated risk factors in our diabetic population. DESIGN: An observational crossover study. SETTING: Primary Care. Concentaina Health Centre. PATIENTS: 144 patients in our centre's diabetes mellitus health programme. MEASUREMENTS AND MAIN RESULTS: There were 31 cases of IOP over 20 mmHg measured with the Schiörtz tonometer, on whom the ophthalmologist repeated the measurement with the Perkins tonometer, i.e. viewing the back of the eye to confirm the existence of papillary cupping consistent with the presence of Glaucoma. We chose a group with normal IOP, homogeneous with the group with high IOP to validate the Schiörtz tonometer, using as confirmation the results obtained by the ophthalmologist with the Perkins tonometer; and as confirmation in the detection of glaucoma, finding papillary excavation in the binocular ophthalmoscopy. Prevalence of glaucoma was 11%, which was 75% in the newly diagnosed cases. The positive predictive value of the Schiörtz tonometer in detecting increases in IOP was 87.1%, and with respect to the detection of glaucoma, it was 35.5%. CONCLUSIONS: The high prevalence of glaucoma in diabetic patients justifies the systematic study of this risk factor. The Schiörtz tonometer is a useful and valid method, that can be used in primary care for glaucoma screening in this population group.

[Evaluation of the completion of influenza vaccination]. / Evaluación del cumplimiento de la vacunación antigripal.

OBJECTIVE: To find the reasons which determine failures to comply with anti-flu vaccinations, so that these can be corrected and the coverage of this preventive action be increased. DESIGN: Observational crossover study, done by means of a telephone survey of people over 65. A questionnaire with closed questions, composed after a pilot study and validated by Cronbach's alpha. SETTING: Primary Care Centre (PCC). PATIENTS: We calculated a population sample for qualitative variables (_ = 0.05; p = 0.60; e = 0.05) of 294 people over 65, chosen from the PCC records, by means of random sampling (K = 4) stratified for age and discounting the telephone selection bias. MEASUREMENTS AND RESULTS: The proportion of vaccinated patients (60.9%) obtained in our study did not significantly differ from that in the general population. The percentage of patients included in the programme for the first time was 14%. Level of satisfaction among those vaccinated was 89.4%, with 8.9% of problems detected being light. Main causes of non-vaccination were: thinking that they didn't need it (63.5%), ignorance of the campaign (35.7%), fear of the reaction (24.3%), forgetting (10.4%). The main form of access to the campaign information was from the PCC, both through individuals and posters. Lack of information was statistically significant (p < 0.00001) as a determinant of non-vaccination, without other factors (age, sex, associated pathologies...) explaining these differences. CONCLUSIONS: Individualised and on-going health education by the PCC is fundamental. This would enable the identification of the group not vaccinated due to their express refusal and the recovery of non-vaccinated patients.

Unsuspected carcinoma of the gallbladder. A laparoscopic dilemma.

Laparoscopic cholecystectomy is the treatment of choice for gallstones. A formal contraindication is gallbladder cancer. However, in a great number of cases, this is a previously unsuspected intraoperative finding, and sometimes its first appearance is in acute cholecystitis. We present the case of 67-year-old woman, which presented an unsuspected carcinoma of the gallbladder that developed abdominal wall implants at the umbilical and left hypocondrium site. The success of LC favors the observation of cases similar to that described in this article. Surgeons who operate using laparoscopic techniques should bear this possibility in mind and practice an extemporaneous biopsy at the slightest suspicion of malignancy, and, if it is confirmed, the operation should be continued as an open one.