Early Impact of Cardiopulmonary Bypass on Renal Function after Valve Replacement Surgery.

Renal dysfunction following cardiopulmonary bypass is well recognized. The pathophysiology of renal injury is multifactorial and culmination of the interplay of several pathophysiological mechanism. Cardiac surgery requiring cardiopulmonary bypass (CPB) is being carried out on an extended patient population of different age groups and undergoing complex surgical procedure, and thus it places them at an increased risk of renal impairment. Valve replacement surgery is a major and complex surgical procedure requiring CPB. This study was therefore designed to observe the impact of CPB and short term outcome on patients with reduced estimated Glomerular Filtration Rate (eGFR) (60-89ml/min/1.73m²) after valve replacement surgery. This cross-sectional study was conducted in the Department of Cardiac Surgery, National Institute of Cardio Vascular Diseases (NICVD) during the period of January 2015 to August 2016. After fulfillment of enrollment criteria 100 patients were studied for the purpose of the study and they were grouped in two, patients with normal eGFR (≥90ml/min/1.73m²) in Group A and patients with reduced eGFR (60-89ml/min/1.73m²) in Group B. A total of 100 patients, 50 in each group were studied for renal function alteration after valve replacement surgery under cardiopulmonary bypass. The incidence of Acute Kidney Injury (AKI) was higher in Group B. Chi-square test was done and p value was 0.011 which is statistically significant. Postoperative blood loss (ml/hr) (p=0.038), duration of Intensive Care Unit (ICU) stay (in hours) (p=0.009), postoperative hospital stay (days) (p=0.014) was significantly higher and postoperative Urine Output (ml/hr) (p=0.001) was significantly lower in patients with reduced eGFR (60-89ml/min/1.73m²) in Group B. Deterioration of renal function is more in patient with eGFR (60-89ml/min/1.73m²) after valve replacement surgery under cardiopulmonary bypass in comparison with patients with eGFR (≥90ml/min/1.73m²).

The Ising triangular-lattice antiferromagnet neodymium heptatantalate as a quantum spin liquid candidate.

Disordered magnetic states known as spin liquids are of paramount importance in both fundamental and applied science. A classical state of this kind was predicted for the Ising antiferromagnetic triangular model, while additional non-commuting exchange terms were proposed to induce its quantum version-a quantum spin liquid. However, these predictions have not yet been confirmed experimentally. Here, we report evidence for such a state in the triangular-lattice antiferromagnet NdTa7O19. We determine its magnetic ground state, which is characterized by effective spin-1/2 degrees of freedom with Ising-like nearest-neighbour correlations and gives rise to spin excitations persisting down to the lowest accessible temperature of 40 mK. Our study demonstrates the key role of strong spin-orbit coupling in stabilizing spin liquids that result from magnetic anisotropy and highlights the large family of rare-earth (RE) heptatantalates RETa7O19 as a framework for realization of these states, which represent a promising platform for quantum applications.

Chiral singlet superconductivity in the weakly correlated metal LaPt3P.

Chiral superconductors are novel topological materials with finite angular momentum Cooper pairs circulating around a unique chiral axis, thereby spontaneously breaking time-reversal symmetry. They are rather scarce and usually feature triplet pairing: a canonical example is the chiral p-wave state realized in the A-phase of superfluid He3. Chiral triplet superconductors are, however, topologically fragile with the corresponding gapless boundary modes only weakly protected against symmetry-preserving perturbations in contrast to their singlet counterparts. Using muon spin relaxation measurements, here we report that the weakly correlated pnictide compound LaPt3P has the two key features of a chiral superconductor: spontaneous magnetic fields inside the superconducting state indicating broken time-reversal symmetry and low temperature linear behaviour in the superfluid density indicating line nodes in the order parameter. Using symmetry analysis, first principles band structure calculation and mean-field theory, we unambiguously establish that the superconducting ground state of LaPt3P is a chiral d-wave singlet.

Risk factors for bovine anthrax in Bangladesh, 2010-2014: a case-control study.

A matched case-control study was conducted in Bangladesh by enrolling case smallholdings of cattle affected with anthrax in the period of October 2010 to December 2014. The cases were initially reported by mass media and/or in surveillance reports from authorities concerned in the country. In total, 43 case smallholdings were enrolled. For each case, a control was matched by similarity in herd-size and rearing of animals, selected from a distantly located (within 3-10 km) place but within the same sub-district of the case farm. Data collected by administering a prototype questionnaire were analysed by matched-pair analysis and multivariable conditional logistic regression. Out of the 43 smallholdings, 41 were located in three adjoining districts: Pabna, Sirajganj and Tangail, apparently forming a spatial cluster, could be termed 'anthrax hot spot' in Bangladesh. Sick animal on farm or a nearby farm slaughtered in the recent past (odds ratio (OR) 12.2, 95% confidence interval (CI) 1.6-93.4, P = 0.016)), history of heavy rains occurring in the last 2 weeks preceding an outbreak (OR 13.1, 95% CI 1.2-147.1, P = 0.037) and disposing of dead animal into nearby water body (OR 11.9, 95% CI 1.0-145.3, P = 0.052) were independent risk factors for anthrax in cattle in the country.

Significant Left Main Coronary Artery Disease Does Not Incur Any Additional Risk to the Short Term Outcome of Off Pump Coronary Artery Bypass Grafting Surgery.

Coronary artery disease is the most common form of heart disease and single most important cause of premature death in developed countries. Off pump coronary artery bypass grafting surgery has recently became widespread internationally and has produced good clinical outcome even in left main coronary artery disease following off pump coronary artery bypass grafting surgery. A prospective observational study was conducted in the department of Cardiac Surgery, National Heart Foundation Hospital and Research Institute, Dhaka, Bangladesh from January 2015 to September 2016 after fulfillment of enrollment criteria, 428 patients were studied for the purpose of the study and they were grouped in two, significant left main coronary artery disease in group A and non left main coronary artery disease requiring surgery in group B. Comparison of risk factors between groups demonstrates that diabetes mellitus and smoking habit between two groups were almost identical. 69.2% of patient with significant left main coronary artery group were hypertensive and 25.2% were dyslipidaemic in comparison to non left main coronary artery disease group which were 50.9% and 6.5% respectively. Requirement of per operative inotropic support was significantly higher in left main coronary artery group. 33.6% of patient of left main coronary artery group required per operative inotropic support whereas non left main coronary artery group require 24.8%. Postoperative inotropic support, mechanical ventilation time, ICU stay, hospital stay and complication were similar in both these groups. So, we can say that off pump coronary artery bypass grafting surgery for significant left main coronary artery disease is as safe as non left main coronary artery disease.

Gapless Quantum Spin Liquid in the Triangular System Sr_{3}CuSb_{2}O_{9}.

We report gapless quantum spin liquid behavior in the layered triangular Sr_{3}CuSb_{2}O_{9} system. X-ray diffraction shows superlattice reflections associated with atomic site ordering into triangular Cu planes well separated by Sb planes. Muon spin relaxation measurements show that the S=1/2 moments at the magnetically active Cu sites remain dynamic down to 65 mK in spite of a large antiferromagnetic exchange scale evidenced by a large Curie-Weiss temperature θ_{CW}≃-143 K as extracted from the bulk susceptibility. Specific heat measurements also show no sign of long-range order down to 0.35 K. The magnetic specific heat (C_{m}) below 5 K reveals a C_{m}=γT+αT^{2} behavior. The significant T^{2} contribution to the magnetic specific heat invites a phenomenology in terms of the so-called Dirac spinon excitations with a linear dispersion. From the low-T specific heat data, we estimate the dominant exchange scale to be ∼36 K using a Dirac spin liquid ansatz which is not far from the values inferred from microscopic density functional theory calculations (∼45 K) as well as high-temperature susceptibility analysis (∼70 K). The linear specific heat coefficient is about 18 mJ/mol K^{2} which is somewhat larger than for typical Fermi liquids.

Ir 5d-band derived superconductivity in LaIr3.

The superconducting properties of rhombohedral LaIr3 were examined using susceptibility, resistivity, heat capacity, and zero-field (ZF) and transverse-field (TF) muon spin relaxation and rotation ([Formula: see text]SR) measurements. The susceptibility and resistivity measurements confirm a superconducting transition below [Formula: see text] K. Two successive transitions are observed in the heat capacity data, one at [Formula: see text] K and a second at 1.2 K below [Formula: see text]. The heat capacity jump is [Formula: see text], which is lower than 1.43 expected for Bardeen-Cooper-Schrieffer (BCS) weak-coupling limit. TF-[Formula: see text]SR measurements reveal a fully gapped s-wave superconductivity with [Formula: see text], which is small compared to the BCS value of 3.56, suggesting weak-coupling superconductivity. The magnetic penetration depth, [Formula: see text], estimated from TF-[Formula: see text]SR gives [Formula: see text] nm, a superconducting carrier density [Formula: see text] carriers m-3 and a carrier effective-mass enhancement factor [Formula: see text]. ZF-[Formula: see text]SR data show no evidence for any spontaneous magnetic fields below [Formula: see text], which demonstrates that time-reversal symmetry is preserved in the superconducting state of LaIr3.

Nodeless s-wave superconductivity in the [Formula: see text]-Mn structure type noncentrosymmetric superconductor TaOs: a [Formula: see text]SR study.

Noncentrosymmetric superconductors can lead to a variety of exotic properties in the superconducting state such as line nodes, multigap behavior, and time-reversal symmetry breaking. In this paper, we report the properties of a new noncentrosymmetric superconductor TaOs, using muon spin relaxation and rotation measurements. It is shown using the zero-field muon experiment that TaOs preserve the time-reversal symmetry in the superconducting state. From the transverse field muon measurements, we extract the temperature dependence of [Formula: see text], which is proportional to the superfluid density. This data can be fit with a fully gapped s-wave model for [Formula: see text] = 2.01 [Formula: see text] 0.02. Furthermore, the value of magnetic penetration depth is found to be 5919 [Formula: see text] 45 [Formula: see text], which is consistent with the value obtained from the bulk measurements.

Investigation of superconducting gap structure in HfIrSi using muon spin relaxation/rotation.

We have investigated the superconducting state of HfIrSi using magnetization, specific heat, muon spin rotation and relaxation ([Formula: see text]SR) measurements. Superconductivity was observed at [Formula: see text] K in both specific heat and magnetization measurements. From an analysis of the transverse-field [Formula: see text]SR data, it is clear that the temperature variation of superfluid density is well fitted by an isotropic Bardeen-Cooper-Schrieffer (BCS) type s-wave gap structure. The superconducting carrier density [Formula: see text] m-3, the magnetic penetration depth, [Formula: see text] nm, and the effective mass, [Formula: see text], were calculated from the TF-[Formula: see text]SR data. Zero-field [Formula: see text]SR data for HfIrSi reveal the absence of any spontaneous magnetic moments below [Formula: see text], indicating that time-reversal symmetry (TRS) is preserved in the superconducting state of HfIrSi. Theoretical investigations suggest that the Hf and Ir atoms hybridize strongly along the c-axis, and that this is responsible for the strong three-dimensionality of this system which screens the Coulomb interaction. As a result, despite the presence of d-electrons in HfIrSi, these correlation effects are weakened, making the electron-phonon coupling more important.

Laparoscopic Adrenalectomy: Two Years Experience at Bangabandhu Sheikh Mujib Medical University.

Laparoscopic surgery has become an efficient tool for many complex surgical procedures. In last decades, laparoscopic adrenalectomy has become a more viable option for removal of adrenal pathology, with many surgeons preferring it to the conventional open technique. This study was done to evaluate the outcomes of lateral transperitoneal adrenalectomy (LTA) in our department and evaluate the feasibility of lateral transperitoneal adrenalectomy (LTA) in our perspective. This study is case series observational study carried out at Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from March 2015 to May 2017. Suspected primary adrenal malignancies were excluded. Seventeen (17) patients (10 male and 7 females with mean age of 35.29 years) underwent 18 adrenalectomy (one bilateral). Seventeen (17) adrenal tumours were resected through laparoscopy and one adrenal tumour is resected through open approach due to conversion. All the patients underwent hormonal evaluation, ultrasonogram and computed tomography of whole abdomen. Ten (10) patients (58.82%) had hormonal active adrenal mass. Seven (7) patients (41.18%) were asymptomatic of which 2 had associated cholelithiasis, 7 patients had generalized weakness, 3 had weight gain with Cushing syndrome (one drug induced) and one had Hirsutism with musculanizing effect. Nine (9) patients had hypertension and 6 patients had diabetes mellitus. Eight (8) right, 8 left and 1 bilateral LTA were performed. The mean age of the patients were 35.29 years, adrenal tumour size ranges from 15-65mm and operation time ranges from 75-120 minutes for unilateral adrenalectomies and 220 minutes for bilateral adrenalectomy. Estimated blood loss ranges from 30 to 130 ml in 16 cases and in one case it was 220 ml in which conversion was done. Mean post operative stay in hospital was 3.94 days. In 16 cases no major or minor complications were observed but in one case due to haemorrhage and infiltration of the tumour to kidney conversion are done in the form of right adrenalectomy with upper partial nephrectomy (Histopathology revealed angiomyolipoma). In pathological examination 9 patients (52.94%) had adrenocortical adenoma, 2 patients (11.76%) had phaeochromocytoma including bilateral one, 2 patients (11.76%) had myolipoma of which one converted to open, 2 patients (11.76%) had adrenocortical hyperplasia, one patient (5.88%) had adrenal cyst and one patient (5.88%) had haemorrhagic cyst. LTA is a safe and efficient minimally invasive treatment options for both secreting and non secreting adrenal masses. The procedure has a learning curve and should be performed by a surgeon experienced in both open and laparoscopic adrenal surgery.

Nodular Mucinosis of Male Breast: A Rare Case Report.

Multinodular accumulation of stromal mucin in breast known as nodular mucinosis is an extremely rare condition of breast. Alternatively it is known as myxoma or nerve sheath myxoma of breast. This benign lesion is confined to only nipple and areola region presenting as slow growing, soft and non tender lobulated mass. Histopathologically it reveals well circumscribed non-encapsulated myxoid/mucinous lesion with few infiltration of spindle cells within a collaginized stroma. The mucinous substance is stained positively with Alcian blue. Mucinous carcinoma or phylloids tumour are important differential diagnosis of nodular mucinosis of breast. Here we report a case of nodular mucinosis of male breast with clinical, radiological and pathological findings with differential diagnosis and treatment modalities.

Breakdown of Magnetic Order in the Pressurized Kitaev Iridate ß-Li_{2}IrO_{3}.

Temperature-pressure phase diagram of the Kitaev hyperhoneycomb iridate ß-Li_{2}IrO_{3} is explored using magnetization, thermal expansion, magnetostriction, and muon spin rotation measurements, as well as single-crystal x-ray diffraction under pressure and ab initio calculations. The Néel temperature of ß-Li_{2}IrO_{3} increases with the slope of 0.9 K/GPa upon initial compression, but the reduction in the polarization field H_{c} reflects a growing instability of the incommensurate order. At 1.4 GPa, the ordered state breaks down upon a first-order transition, giving way to a new ground state marked by the coexistence of dynamically correlated and frozen spins. This partial freezing in the absence of any conspicuous structural defects may indicate the classical nature of the resulting pressure-induced spin liquid, an observation paralleled to the increase in the nearest-neighbor off-diagonal exchange Γ under pressure.

Incidence of contamination of live bird markets in Bangladesh with influenza A virus and subtypes H5, H7 and H9.

In the absence of robust active surveillance of avian influenza viruses (AIV) affecting poultry in South Asian countries, monitoring of live bird markets (LBMs) can be an alternative. In a longitudinal study of 32 LBM, five environments were sampled as follows: market floor, stall floor, slaughter area, poultry holding cage and water used for meat processing. Samples were taken monthly for 5 months, September 2013-January 2014. Incidence rates (IRs) of LBM contamination with AIV and its subtypes H5, H7 and H9 were assessed. In 10 of the LBM selected, biosecurity measures had been implemented through FAO interventions: the other 22 were non-intervened. Standard procedures were applied to detect AIV and three subtypes in pooled samples (1:5). An LBM was considered positive for AIV or a subtype if at least one of the pooled samples tested positive. The incidence rates of LBM contamination with AIV, H5, H7 and H9 were 0.194 (95% confidence interval (CI) 0.136-0.276), 0.031 (95% CI 0.013-0.075), 0 and 0.175 (95% CI 0.12-0.253) per LBM-month at risk, respectively. The log IR ratio between the FAO-intervened and non-intervened LBM for contamination with AIV was -0.329 (95% CI -1.052 to -0.394, p = .372), 0.598 (95% CI -1.593 to 2.789, p = .593) with subtype H5 and -0.500 (95% CI -1.249 to 0.248, p = .190) with subtype H9, indicating no significant difference. The results obtained suggest that both H5 and H9 were circulating in LBM in Bangladesh in the second half of 2013. The incidence of contamination with H9 was much higher than with H5.

Biosecurity and Circulation of Influenza A (H5N1) Virus in Live-Bird Markets in Bangladesh, 2012.

Bangladesh has been considered as one of the five countries endemic with highly pathogenic avian influenza A subtype H5N1 (HPAI H5N1). Live-bird markets (LBMs) in south Asian countries are believed to play important roles in the transmission of HPAI H5N1 and others due to its central location as a hub of the poultry trading. Food and Agriculture Organization (FAO) of the United Nations has been promoting improved biosecurity in LBMs in Bangladesh. In 2012, by enrolling 32 large LBMs: 10 with FAO interventions and 22 without assistance, we assessed the virus circulation in the selected LBMs by applying standard procedures to investigate market floors, poultry stall floors, poultry-holding cases and slaughter areas and the overall biosecurity using a questionnaire-based survey. Relative risk (RR) was examined to compare the prevalence of HPAI H5N1 in the intervened and non-intervened LBMs. The measures practised in significantly more of the FAO-intervened LBMs included keeping of slaughter remnants in a closed container; decontamination of poultry vehicles at market place; prevention of crows' access to LBM, market/floor cleaning by market committee; wet cleaning; disinfection of floor/poultry stall after cleaning; and good supply of clean water at market (P < 0.05). Conversely, disposal of slaughter remnants elsewhere at market and dry cleaning were in operation in more of the FAO non-intervened LBMs (P < 0.05). The RR for HPAI H5N1 in the intervened and non-intervened LBMs was 1.1 (95% confidence interval 0.44-2.76), suggesting that the proportion positive of the virus in the two kinds of LBM did not vary significantly (P = 0.413). These observations suggest that the viruses are still maintained at the level of production in farms and circulating in LBMs in Bangladesh regardless of interventions, albeit at lower levels than in other endemic countries.

Designer interface peptide grafts target estrogen receptor alpha dimerization.

The nuclear transcription factor estrogen receptor alpha (ERα), triggered by its cognate ligand estrogen, regulates a variety of cellular signaling events. ERα is expressed in 70% of breast cancers and is a widely validated target for anti-breast cancer drug discovery. Administration of anti-estrogen to block estrogen receptor activation is still a viable anti-breast cancer treatment option but anti-estrogen resistance has been a significant bottle-neck. Dimerization of estrogen receptor is required for ER activation. Blocking ERα dimerization is therefore a complementary and alternative strategy to combat anti-estrogen resistance. Dimer interface peptide "I-box" derived from ER residues 503-518 specifically blocks ER dimerization. Recently using a comprehensive molecular simulation we studied the interaction dynamics of ERα LBDs in a homo-dimer. Based on this study, we identified three interface recognition peptide motifs LDKITDT (ERα residues 479-485), LQQQHQRLAQ (residues 497-506), and LSHIRHMSNK (residues 511-520) and reported the suitability of using LQQQHQRLAQ (ER 497-506) as a template to design inhibitors of ERα dimerization. Stability and self-aggregation of peptide based therapeutics poses a significant bottle-neck to proceed further. In this study utilizing peptide grafted to preserve their pharmacophoric recognition motif and assessed their stability and potential to block ERα mediated activity in silico and in vitro. The Grafted peptides blocked ERα mediated cell proliferation and viability of breast cancer cells but did not alter their apoptotic fate. We believe the structural clues identified in this study can be used to identify novel peptidometics and small molecules that specifically target ER dimer interface generating a new breed of anti-cancer agents.

Prevalence of sorbitol non-fermenting Shiga toxin-producing Escherichia coli in Black Bengal goats on smallholdings.

A cross-sectional survey was carried out in Bangladesh with the sampling of 514 Black Bengal goats on smallholdings to determine the presence of sorbitol non-fermenting (SNF) Shiga toxin-producing E. coli (STEC). Swab samples collected from the recto-anal junction were plated onto cefixime and potassium tellurite added sorbitol MacConkey (CT-SMAC) agar, a selective medium for STEC O157 serogroup, where this serogroup and other SNF STEC produce colourless colonies. The SNF E. coli (SNF EC) isolates obtained from the survey were investigated by PCR for the presence of Shiga toxin-producing genes, stx1 and stx2, and two other virulence genes, eae and hlyA that code for adherence factor (intimin protein) and pore-forming cytolysin, respectively. The SNF EC isolates were also assessed for the presence of the rfbO157 gene to verify their identity to O157 serogroup. The results revealed that the proportions of goats carrying SNF EC isolates and stx1 and stx2 genes were 6·2% (32/514) [95% confidence interval (CI) 4·4-8·7)], 1·2% (95% CI 0·5-2·6) and 1·2% (95% CI 0·5-2·6), respectively. All the SNF STEC tested negative for rfbO157, hlyA and eae genes. The risk for transmission of STEC from Black Bengal goats to humans is low.

Origin of the Spin-Orbital Liquid State in a Nearly J=0 Iridate Ba_{3}ZnIr_{2}O_{9}.

We show using detailed magnetic and thermodynamic studies and theoretical calculations that the ground state of Ba_{3}ZnIr_{2}O_{9} is a realization of a novel spin-orbital liquid state. Our results reveal that Ba_{3}ZnIr_{2}O_{9} with Ir^{5+} (5d^{4}) ions and strong spin-orbit coupling (SOC) arrives very close to the elusive J=0 state but each Ir ion still possesses a weak moment. Ab initio density functional calculations indicate that this moment is developed due to superexchange, mediated by a strong intradimer hopping mechanism. While the Ir spins within the structural Ir_{2}O_{9} dimer are expected to form a spin-orbit singlet state (SOS) with no resultant moment, substantial frustration arising from interdimer exchange interactions induce quantum fluctuations in these possible SOS states favoring a spin-orbital liquid phase down to at least 100 mK.

Direct evidence for a pressure-induced nodal superconducting gap in the Ba0.65Rb0.35Fe2As2 superconductor.

The superconducting gap structure in iron-based high-temperature superconductors (Fe-HTSs) is non-universal. In contrast to other unconventional superconductors, in the Fe-HTSs both d-wave and extended s-wave pairing symmetries are close in energy. Probing the proximity between these very different superconducting states and identifying experimental parameters that can tune them is of central interest. Here we report high-pressure muon spin rotation experiments on the temperature-dependent magnetic penetration depth in the optimally doped nodeless s-wave Fe-HTS Ba0.65Rb0.35Fe2As2. Upon pressure, a strong decrease of the penetration depth in the zero-temperature limit is observed, while the superconducting transition temperature remains nearly constant. More importantly, the low-temperature behaviour of the inverse-squared magnetic penetration depth, which is a direct measure of the superfluid density, changes qualitatively from an exponential saturation at zero pressure to a linear-in-temperature behaviour at higher pressures, indicating that hydrostatic pressure promotes the appearance of nodes in the superconducting gap.

Isosorbide Mononitrate versus Misoprostol for Cervical Ripening and Induction of Labour at Term.

To assess the efficacy and safety of isosorbide mononitrate (IMN) compared with misoprostol for cervical ripening and labour induction at term. In this comparative study two hundred term pregnant women with indication for induction of labour were randomly divided to receive either 40 mg IMN tablet vaginally (n=100) or 50 µg misoprostol tablet vaginally (n=100) every 6 hours interval for a maximum of 4 doses. Progress & outcome of cervical ripening, labour induction and adverse effects were assessed. Change in cervical score was higher in misoprostol group than IMN group. Time from start of medication to vaginal delivery in IMN group was significantly longer, 28.66 ± 5.283 hours, than in misoprostol group, 16.12 ± 5.581 hours. Vaginal delivery occurred in 77% in IMN group and 69% in misoprostol group. There were no tachysystole or uterine hyper stimulation in the IMN group while in misoprostol group it was 17% and 11% respectively. Maternal satisfaction was higher in IMN group. Cervical ripening is satisfactory with IMN. Though misoprostol is singly more effective than IMN but IMN with oxytocin results in more vaginal delivery. Fetal and maternal side effects are less in IMN group.

Sorbitol non-fermenting shiga toxin-producing Escherichia coli in cattle on smallholdings.

We investigated faecal samples collected from the rectum of 518 cattle on 371 randomly selected smallholdings in Bangladesh for the presence of sorbitol non-fermenting (SN-F) shiga toxin-producing Escherichia coli (STEC). The SN-F isolates were tested for the presence of rfb O157, stx1, stx2, eae and hlyA genes by polymerase chain reaction (PCR). Seven SN-F isolates lacking these genes were profiled by pulsed-field gel electrophoresis (PFGE) to verify their clonality. SN-F E. coli was identified in 44 [8·5%, 95% confidence interval (CI) 6·4-11·2] samples; of these, 28 (5·4%, 95% CI 3·8-7·7) had shiga toxin-producing strains, although only two carried the rfb O157 gene. Thirteen isolates carried the hlyA gene while 18 harboured the eae gene. Based on PFGE, six pulsotypes were observed among the seven isolates that had no virulence genes. To the best of our knowledge this is the first report on shiga toxin-producing E. coli from direct rectal faecal samples of cattle on smallholdings.