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.

Household-level risk factors for water contamination and antimicrobial resistance in drinking water among households with children under 5 in rural San Marcos, Cajamarca, Peru

Household water contamination at point of use depends on human, animal and environmental factors embodying all aspects of a One Health approach. This study investigated the association between household factors, the presence of thermotolerant coliform, and the presence of antibiotic resistant bacteria in drinking water among 314 households with children under 5 in Cajamarca, Peru. This study analysed data from a baseline sampling of a randomized controlled trial, including household surveys covering household water management and factors such as household animals, as well as microbiological data from samples collected from drinking water. Data were analysed using generalized linear models. Drinking water samples collected from narrow-mouthed containers were less likely to be contaminated than samples collected from the faucet (OR = 0.55, p = 0.030) or wide mouthed containers. The presence of thermotolerant coliform was associated with owning farm birds, which increased the proportion of contamination from 42.2% to 59.1% (OR = 1.98, p = 0.017) and with animal waste observed in the kitchen area, which increased the prevalence of contamination from 51.4% to 65.6% (OR = 1.80, p = 0.024). Resistance to any antibiotic was higher among pig owners at 60%, relative to non-pig owners at 36.4% (OR = 1.97, p = 0.012) as well as households with free-roaming animals in the kitchen area at 59.6% compared to households without free-roaming animals at 39.7% (OR = 2.24, p = 0.035). Recent child antibiotic use increased the prevalence of trimethoprim-sulfamethoxazole resistance among E. coli isolates to 22.3% relative to 16.7% (OR = 3.00, p = 0.037). Overall, these findings suggest that water storage in a secure container to protect from in-home contamination is likely to be important in providing safe drinking water at point of use. In addition, transmission of thermotolerant coliform and AMR between domestic animals and human drinking water supplies is likely. Further research should explore transmission pathways and methods to support safe drinking water access in multi-species households.

The Relationship between strength and academic performance: A new reason to promote physical activity

Background

Experimental studies have determined that higher strength values are associated with more efficient cognitive function and better academic performance. In spite of this, the universities in Colombia are decreasing the time available for physical activity in favour of increasing the time devoted to theoretical subjects. This is one of the reasons why in Colombia, only 18% of young people complied with the world recommendations of physical activity. To examine this problem, the objective of this research was to establish the relationship between strength and academic performance in university students.

Methods

A cross-sectional study was developed in 135 (21.8 ± 4.5 yr; 78.69 ± 9.1kg) students of the fifth semester of the Areandina University in Bogota, Colombia. Each participant developed incremental protocols to determine the maximum weight that he or she could move in six different exercises: squat in smith machine, leg press, leg extension, bench press, pull down and military press. The average of the results of these tests was taken as the value of maximum strength. To determine academic performance, the average of the scores accumulated in the five semesters of their university studies was evaluated. Pearson correlation coefficient was used to find the linear relationship between strength and academic performance.

Results

Overall, 70.3 % of the participants were men and 29.7% were women. The results of the maximum strength tests were significantly higher in the male group than in the female group (P < 0.05). Academic performance was similar in both genders (P > 0.05). A positive correlation was established between maximum strength and academic performance. (r = 0.64 P < 0.05).

Conclusions

The conclusion of this research was that there is a significant relationship between strength and academic performance. These results are fundamental to justify the inclusion of spaces for the promotion of physical activity in public and private universities.

Key messages

Universities are institutions that only focus on academic training and generate contexts in which sedentary behaviours are promoted. Sedentary lifestyles are a public health problem in Colombia.

Ecological meltdown in predator-free forest fragments

The manner in which terrestrial ecosystems are regulated is controversial. The "top-down" school holds that predators limit herbivores and thereby prevent them from overexploiting vegetation. "Bottom-up" proponents stress the role of plant chemical defenses in limiting plant depredation by herbivores. A set of predator-free islands created by a hydroelectric impoundment in Venezuela allows a test of these competing world views. Limited area restricts the fauna of small (0.25 to 0.9 hectare) islands to predators of invertebrates (birds, lizards, anurans, and spiders), seed predators (rodents), and herbivores (howler monkeys, iguanas, and leaf-cutter ants). Predators of vertebrates are absent, and densities of rodents, howler monkeys, iguanas, and leaf-cutter ants are 10 to 100 times greater than on the nearby mainland, suggesting that predators normally limit their populations. The densities of seedlings and saplings of canopy trees are severely reduced on herbivore-affected islands, providing evidence of a trophic cascade unleashed in the absence of top-down regulation.

Exhaustive generation of organic isomers. 6. Stereoisomers having isolated and spiro cycles and new extended N_tuples

A new stereoisomer generation system named CAMGEC2 for generation of stereoisomers containing isolated and spiro cycles with one or more descriptors among R, S, Z, E, M, and P is developed using Graph Theory. It includes new approaches for symmetry analysis, cycle detection processes in molecular graphs in a modular way, and also an extension of the N_tuple format for linear representation of molecular graphs that keeps graph topographical information.

Design and validation of an ELISA for equine infectious anemia (EIA) diagnosis using synthetic peptides

Three peptides derived from the equine infectious anemia virus (EIAV) surface proteins were synthesized to design and validate an ELISA for EIA diagnosis. Peptides identified as gp90-I and gp90-II correspond to the N- and C-terminal part of the surface glycoprotein gp90. Peptide gp45-1 overlaps the immunodominant epitope CIERTHVFC of the transmembrane glycoprotein gp45, and includes a hydrophilic chain close to the N-terminal end of this nonapeptide loop. Serum samples from 140 naturally infected horses with EIAV and a panel of 167 non-immune equine sera obtained from non-infected animals were used. Differences in reactivity between positive and negative serum samples were clearly distinguished. Samples considered weak positive to the agar gel immunodiffusion (AGID) test were "true" positive in the ELISA. These results are consistent with the improved sensitivity of the ELISA in comparison with the AGID test. The cyclic peptide that mimics the immunodominant sequence of gp45 showed excellent reactivity, thus suggesting that its functional activity depends significantly on its conformation, since very low reactivity was observed in the linear form of the peptide. The detectability indices of positive and negative sera reached 98% when gp90-II and gp45-I synthetic peptides were used in the same assay, illustrating the high specificity and sensitivity of the assay. Our study represents a first approach for the design of a diagnostic kit, which would allow the rapid analysis of a large numbers of serum samples from horses, and could be applied in endemic areas with different prevalence of infection.

Pathologic features of epidermoid carcinoma of the penis. A prospective study of 66 cases

We report a whole-organ-section pathologic study of 66 cases of epidermoid carcinoma of the penis. Specimens were divided into three compartments: glans (G), coronal sulcus (COS), and foreskin (F) with 24, 4, and 12 histologic sections each. Four types of carcinomas were found: (a) superficially spreading (42%), a biphasic infiltrating and extensive carcinoma in situ usually involving more than one compartment and radially growing along the surface of G, BPS, F, or even urethra; (b) vertical growth (32%), unifocal high-grade, deeply invasive neoplasms with minimal or no carcinoma in situ component; (c) verrucous (18%), low-grade papillary or endophytic; and (d) multicentric (8%), two or more independent primary tumors separated by non-neoplastic mucosa. Inguinal lymph node metastasis were found in 82, 42, and 33% of pathologic types vertical growth, superficially spreading, and multicentric carcinomas, respectively; verrucous tumors did not show metastasis. The morphologic diversity of penile cancer may be related to different causative factors. Metastatic involvement suggests a distinctive biological behavior of the tumor. The widespread extension of superficially spreading and multicentric carcinomas to anatomical compartments indicate penile mucosa as one "field" prone to malignant transformation. These findings may be important for the selection of appropriate therapy and emphasize the need for a close follow-up of patients undergoing less than a complete removal of the three compartments.

Hamartoma of the breast

Mammary hamartomas are unusual lesions with distinctive radiologic and pathologic features. They are well circumscribed, mobile tumors showing no adherence to skin or muscle. Mammographic studies show a peripheral, luscent halo, and the mass is radiographically similar in pattern to a normal breast ("breast within a breast"). Calcification is not present. Histologically, these encapsulated lesions are composed of various breast tissue components such as ducts, lobules, stroma prominently adipose, and smooth muscle, without any particular arrangement. Local surgical resection is the treatment of choice. Hamartomas of the breast are benign lesions that need to be distinguished from other breast neoplasms such as fibroadenomas, lipomas, and cystosarcoma phyllodes.

Fontan operation: modification of the valve position in conduit with brief review of the literature

A Fontan operation was performed on a 10-year-old child for correction of tricuspid atresia. A xenograft, valved conduit was used to establish continuity between the right atrium and the small right ventricle. Atrial and ventricular septal defects were repaired with Dacron patches. Two hours postoperatively, the patient suffered a cardiac arrest secondary to hypoxia and was successfully resuscitated. Partial recurrence of a right-to-left shunt at the atrial level necessitated the patient's return to surgery. The insufficient conduit was replaced and the leaking patches were resutured. The conduit was shortened to one-third its length, and the conduit valve was repositioned directly at the proximal end, over the right atriotomy. Ten months postoperatively, the patient remains in stable condition.

Severe blood transfusion reaction from leukoagglutinin antibody with successful treatment by membrane oxygenation

In the intensive care unit immediately after a triple aortocoronary bypass procedure, a 62-year-old man presented with copious amounts of frothy secretions in the endotracheal tube, became severely hypotensive, and remained hypoxic in the presence of maximum respiratory support. Chest roentgenograms showed pronounced pulmonary edema. Prior to leaving the operating room, the patient had received 1 unit of whole blood. A leukoagglutinin reaction to this blood transfusion was determined to be the cause of the pulmonary edema. When the patient continued to deteriorate after administration of diuretics, vasopressors, corticosteroids, albumin, and maximum respiratory support, the Sci-Med membrane oxygenator was inserted by the right femoral vein-artery. Bypass was continued for approximately 8 hours, until the PaO2 increased and the patient's condition stabilized. We think this is the first reported case of membrane oxygenation for treatment of noncardiogenic pulmonary edema due to leukoagglutinin reaction. It indicates the need for early diagnosis and utilization of the membrane oxygenator when other methods of treatment fail.