Detection of antimicrobial resistance genes in extended spectrum beta-lactamase-producing Escherichia coli from milk of indigenous Beetal goats of Punjab.

Background: Antimicrobial resistance (AMR) is a burning issue in the present era. Mastitis in dairy animals is one of the most important causes of huge production loss to dairy farmers. Aims: The study aims to find the prevalence, antimicrobial resistance profile, and resistance genes in the extended-spectrum beta-lactamase-producing Escherichia coli in mastitic milk. Methods: A total of 125 milk samples were collected from Beetal goats suffering from clinical mastitis from different districts of Punjab and processed for bacterial isolation and further identification. The drug resistance profile of ESBL-producing E. coli and its associations with molecular markers was analyzed using statistical analysis. Results: The prevalence of ESBL-producing E. coli in dairy goats of Punjab was recorded as 6.4%. The isolates showed the highest resistance to the beta-lactam group of antibiotics. The resistance percentages of streptomycin, gentamicin, tetracycline, chloramphenicol, clotrimazole, and colistin were 50%, 37.5%, 50%, 25%, 25%, and 50%, respectively. The isolates showed intermediate resistance to imipenem (12.5%) and tetracycline (25%). The ESBL-producing E. coli isolates harbored the resistance genes blaCTXM (100%), blaTEM (62.5%), blaSHV (25%), blaOXA (37.5%), tetA (37.5%), tetB (25%), aadA (37.5%), sul1 (25%), MOXM (12.5%), DHAM (25%), and blaCMY-2 (50%). Tetracycline and sulphonamide resistances were statistically associated with their respective resistance genes (P<0.05). Streptomycin resistance was not statistically associated with the presence of the aadA gene (P>0.05). The genes blaIMP and blaNDM were not recorded in any of the isolates. In this study, 12.5% of the isolates showed co-resistance to colistin and carbapenem. Conclusion: Antimicrobial resistance is a hot topic and requires immediate attention.

Prevalence and antimicrobial resistance of food safety related Vibrio species in inland saline water shrimp culture farms.

This study evaluated the potential pathogenicity and antimicrobial resistance (AMR) of Vibrio species isolated from inland saline shrimp culture farms. Out of 200 Vibrio isolates obtained from 166 shrimp/water samples, 105 isolates were identified as V. parahaemolyticus and 31 isolates were identified as V. alginolyticus and V. cholerae, respectively. During PCR screening of virulence-associated genes, the presence of the tlh gene was confirmed in 70 and 19 isolates of V. parahaemolyticus and V. alginolyticus, respectively. Besides, 10 isolates of V. parahaemolyticus were also found positive for trh gene. During antibiotic susceptibility testing (AST), very high resistance to cefotaxime (93.0%), amoxiclav (90.3%), ampicillin (88.2%), and ceftazidime (73.7%) was observed in all Vibrio species. Multiple antibiotic resistance (MAR) index values of Vibrio isolates ranged from 0.00 to 0.75, with 90.1% of isolates showing resistance to ≥ 3 antibiotics. The AST and MAR patterns did not significantly vary sample-wise or Vibrio species-wise. During the minimum inhibitory concentration (MIC) testing of various antibiotics against Vibrio isolates, the highest MIC values were recorded for amoxiclav followed by kanamycin. These results indicated that multi-drug resistant Vibrio species could act as the reservoirs of antibiotic resistance genes in the shrimp culture environment. The limited host range of 12 previously isolated V. parahaemolyticus phages against V. parahaemolyticus isolates from this study indicated that multiple strains of V. parahaemolyticus were prevalent in inland saline shrimp culture farms. The findings of the current study emphasize that routine monitoring of emerging aquaculture areas is critical for AMR pathogen risk assessment.

Complete genome sequencing and characterization of single-stranded DNA Vibrio parahaemolyticus phage from inland saline aquaculture environment.

Despite their evolutionary, molecular biology and biotechnological significance, relatively fewer numbers of single-stranded DNA (ssDNA) filamentous phages belonging to the family Inoviridae have been discovered and characterized to date. The present study focused on genome sequencing and characterization of an ssDNA Vibrio parahaemolyticus phage V5 previously isolated from an inland saline shrimp culture farm. The complete circular genome of phage V5 consisted of 6658 bp with GC content of 43.7%. During BLASTn analysis, only 36% of phage V5 genome matched with other Vibrio phage genomes in the NCBI database with a sequence identity value of 79%. During the phylogenetic analysis, phage V5 formed a separate branch in the minor clade. These features indicate the novel nature of the phage V5 genome. Among 10 predicted open reading frames (ORFs) in the phage V5 genome, 6 encoded for the proteins of known biological functions, whereas the rest were classified as hypotheticals. Proteins involved in replication and structural assembly were encoded by the phage genome. However, the absence of genes encoding for DNA/RNA polymerases and tRNAs signified that phage V5 is dependent on the host`s molecular machinery for its propagation. As per our knowledge, this is the first study describing the novel genome sequence of an ssDNA V. parahaemolyticus phage from the inland saline environment.

Antibiotic sensitivity patterns in Staphylococcus spp. isolated from goat milk in association with molecular detection of antibiotic resistance genes.

BACKGROUND: Microbes become unresponsive to the drugs used to treat infections due to their ability to acquire antimicrobial resistance. AIMS: The present research aimed to study the patterns of phenotypic and genotypic antimicrobial resistance in Staphylococcus spp. isolated from goat milk. METHODS: A total of 200 milk samples were collected to isolate Staphylococcus spp. from mastitic and healthy goats from Punjab state, India. The isolates were then identified biochemically and molecularly (polymerase chain reaction (PCR)). An antibiotic sensitivity test was conducted using 15 different antibiotics. Molecular detection of antibiotic resistance genes was done using PCR. Chi-square test was done to study the association between genotypic and phenotypic resistance patterns among the isolates. RESULTS: A total of 47 Staphylococcus spp. were isolated of which 33 and 14 isolates were respectively coagulase positive and negative. The isolates phenotypically showed the highest resistance to Penicillin G (P) (91.4%). Methicillin resistant Staphylococcus aureus (MRSA) was found 56.25%. Amongst the antibiotic resistance genes, tetK (87.23%) was the most prevalent isolated gene followed by blaZ (85.10%), mecA (48.93%), and tetM (14.89%). Statistical analysis revealed that the genotypic and phenotypic resistance patterns were significantly associated with penicillin and methicillin (MET) resistances. CONCLUSION: The high prevalence of antibiotic-resistant Staphylococcus spp., especially MRSA, in goat milk is of concern and needs to be addressed in this area.

Subclinical endometritis in estrual buffaloes: diagnosis, prevalence and impact on reproductive performance.

The study evaluated the reliability of polymorphonuclear (PMN) cell count in endometrial cytology by cytobrush technique as a diagnostic for subclinical endometritis (SCE) at the time of estrus and its relationship with bacterial presence and fertility in buffaloes. Healthy pluriparous buffaloes (n = 115) were subjected to endometrial sampling by cytobrush technique (for cytology and bacterial isolation) and ultrasonography of genitalia prior to insemination at the time of spontaneous estrus. Buffaloes were inseminated at the same estrus and were confirmed for pregnancy by ultrasonography at day 40 post-insemination. Growth of aerobic bacteria was recorded in 26.1% (30/115) of estrual buffaloes. Bacteria of eight distinct genera (Staphylococcus spp., Bacillus spp., Proteus spp., Escherichia coli, Klebsiella spp., Streptococcus spp., Pseudomonas spp. and T. pyogenes) were isolated. Presence of bacterial infection was considered as the standard, against which PMN threshold for SCE was calculated by receiver operator curve (ROC). The PMN count of ≥ 5% with good sensitivity (66.7, 95% CI 50.9-81.4) and specificity (87.0%, 95% CI 78.0-94.6) with an overall high diagnostic accuracy (81.7%) for predicting SCE was obtained. Based on calculated PMN threshold, buffaloes were divided into subclinical endometritic (SCE; ≥ 5% PMNs) and control (< 5% PMNs) groups. Thirty-one buffaloes (27.0%, 31/115) had ≥ 5% PMNs in the endometrial cytology at estrus. Ultrasonographic evaluation showed that size of largest follicle, endometrial thickness, and uterine horn diameter did not differ significantly (P > 0.05) between the two groups. Significantly, lower conception rate (22.58 vs 36.90%, P < 0.05) for first artificial inseminations (AIs) and significantly higher number of AIs per pregnancy (2.81 ± 0.27 vs 1.75 ± 0.15, P < 0.05) were recorded in SCE compared to control group. The results indicated that cytobrush based endometrial cytology with 5% PMN cut-off value has a good accuracy for predicting subclinical endometritis at estrus in buffaloes.

Primary photodynamic therapy with verteporfin for small pigmented posterior pole choroidal melanoma.

PurposeThe purpose of the study was to investigate the outcomes of primary photodynamic therapy (PDT) for small pigmented posterior pole choroidal melanoma.Patients and methodsProspective interventional consecutive case series of 15 patients with small pigmented posterior pole choroidal melanoma, who were treated with three sessions of PDT and followed-up thereafter. Risk factors for failure were assessed and outcome measures at presentation were compared to those at last follow-up visit.ResultsTumor control was achieved in 12 (80%) patients in a median follow-up time of 15 months (mean 14, range 8-18). Three patients failed treatment, diagnosed in a median time of 5 months (mean 4, range 3-6), after first PDT. In all failed cases, lesions were 100% pigmented; de novo melanoma rather than transformed nevi and showed a radial growth pattern rather than increased thickness. All failed cases were subsequently successfully treated with radiotherapy. In this cohort, subretinal fluid (SRF) was significantly reduced (P<0.001), vision did not deteriorate (P=0.11) and even improved in patients with subfoveal SRF at presentation (P=0.018), tumor height significantly decreased (P=0.037) and no complications were recorded.ConclusionPrimary PDT was found to be a safe and efficient treatment modality for small pigmented posterior pole choroidal melanoma, achieving short-term tumor control in 80% of patients. PDT offers patients the opportunity to preserve vision by avoiding the retinopathy associated with conventional radiation treatments for choroidal melanoma. However, the long-term local control of these tumors remains uncertain.

Intravitreal bevacizumab monotherapy for choroidal neovascularisation secondary to choroidal osteoma.

PurposeThe purpose of this study is to present the outcomes of a series of patients with choroidal neovascular membrane (choroidal neovascularisation (CNV)) secondary to a choroidal osteoma undergoing anti-VEGF monotherapy.Patients and methodsRetrospective series of patients with choroidal neovascularization secondary to choroidal osteoma. All patients underwent clinical and imaging assessment (fundus photo, B-scan ultrasonography, fluorescein angiography, and optical coherence tomography-where available), and were managed with intravitreal anti-VEGF injections (Bevacizumab). Visual acuity and central retinal thickness were recorded pre treatment and at the end of the follow-up period.ResultsEight patients were included in this study. Of this, 6/8 had predominantly classic or classic and 2/8 patients had minimally classic or occult CNV. Each patient received 3-10 injections of bevacizumab. Median follow-up was 9 months (3-15 months). Visual acuity improved in 5 patients, by 2-6 Snellen lines. CNV completely regressed in 5 cases and partially regressed in 3 cases. Mean CRT reduction was 122 µm (6 to -230 µm).ConclusionIntravitreal bevacizumab can be an effective treatment modality in the management of vision threatening CNV secondary to choroidal osteoma.

Lepromatous leprosy: An Unusual Presentation.

A 25 year old man presented with loss of sensations over both hands and feet and extreme difficulty in passing urine. On examination, an indurated sclerotic plaque was present on shaft of penis and scrotum in addition to other features of lepromatous leprosy. Skin biopsy from the penile lesion showed presence of a large number of acid fast bacilli with a BI of 6+ extending into the epidermis and histopathology showed absence of Grenz zone and presence of foamy macrophages in the dermis up to the dermo-epidermal junction.

Draft Genome Sequences of Two Brucella abortus Strains Isolated from Cattle and Pig.

We report the draft genome sequences of two Brucella abortus strains LMN1 and LMN2 isolated from cattle and pig. The LMN1 and LMN2 have the genome size of 3,395,952 bp and 3,334,792 bp, respectively. In addition to the conserved genes of Brucella, few novel regions showing similarity to the phages were identified in both strains.

Choroidal metastasis from follicular cell thyroid carcinoma masquerading as circumscribed choroidal haemangioma.

Choroidal metastases from follicular thyroid carcinoma are uncommon and usually present as an amelanotic lesion against a background of known systemic disease. We present the case of a 56-year-old woman with a thyroid metastatic focus with unusual clinical presentation, systemic involvement, and early response to systemic treatment. A review of the literature accompanies this case presentation.

Composition and temperature-induced structural changes in lead-tellurite glasses on different length scales.

Processes occurring at macroscopic and microscopic length scales across the glass transition (T(g)) in lead-tellurite glass (PbO)(x)(TeO(2))(1-x) (x = 0.1-0.3) are investigated using Brillouin and Raman spectroscopy, respectively. For all the samples, the temperature dependence of the longitudinal acoustic (LA) mode is found to exhibit a universal scaling below T(g) and a rapid softening above T(g). The lower value of elastic modulus at a higher concentration of network modifier PbO, estimated from Brillouin data, arises due to loss of network rigidity. From quantitative analysis of the reduced Raman spectra, several modes are found to exhibit anomalous changes across T(g). Instead of the expected anharmonic behaviour, several modes exhibit hardening, suggesting stiffening of the stretching force constants with temperature, the effect being more pronounced in glasses with higher x. In addition, incorporation of PbO in the glass is also found to narrow down the bond-length distribution, as evident from the sharpening of the Raman bands. The stiffening of the force constants of molecular units at a microscopic length scale and the decrease of elastic constant attributed to loss of network rigidity on a macroscopic length scale appear to be opposite. These different behaviours at two length scales are understood on the basis of a microscopic model involving TeO(n) and PbO units in the structure.

Quenchable high-density amorphous polymorphs of zirconium tungstate.

Zirconium tungstate turns amorphous above 2 GPa. Amorphous-Zr(WO(4))(2) is studied in situ using synchrotron x-ray diffraction and Raman spectroscopy at high pressure. The height and the position of the first peak of the structure factor as a function of pressure exhibit discontinuous changes suggesting an amorphous to amorphous transformation around 19 GPa. The pressure dependence of the Raman mode frequencies of the tungstate tetrahedra also exhibits a change at the same pressure. The high-density amorphous form appears to have higher oxygen coordination as compared to the low-density amorphous form.

Laser-power-induced multiphonon resonant raman scattering in laser-heated CdS nanocrystal.

The size stability of nanoparticles is crucial from an application point of view. We probe, using Raman spectroscopy, particle size evolution of CdS nanoparticles by varying laser power. Multiphonon resonant Raman scattering has also been demonstrated. With increase in laser power, the intensity ratio of 2-longitudinal optical (LO) to 1-LO is found to increase dramatically, and LO phonon overtones up to fourth order are observed. Resonant Raman scattering has been achieved by suitably matching the band gap with the excitation photon energy, by varying the local temperature. The effect of increase in local temperature on the band gap is also discussed.

Confined acoustic phonon in CdSC(1-x)Se(x) nanoparticles in borosilicate glass.

We calculate low-frequency Raman scattering from the confined acoustic phonon modes of CdS(1-x)Se(x) nanoparticles embedded in borosilicate glass. The calculation of the Raman scattering by acoustic phonons in nanoparticles has been performed by using third-order perturbation theory. The deformation potential approximation is used to describe the electron-phonon interaction. The Raman-Brillouin electronic density and the electron-phonon interaction are found to increases with decreasing size of nanoparticle. A good agreement between the calculated and reported low-frequency Raman spectra is found.

Phonon confinement in stressed silicon nanocluster.

Confined acoustic and optical phonons in Si nanoclusters embedded in sapphire, synthesized using ion-beam implantation are investigated using Raman spectroscopy. The l=0 and l=2 confined acoustic phonons, found at low Raman shift, are analyzed using complex frequency model and the size of the nanoparticles are estimated as 4 and 6 nm. For the confined optical phonon, in contrast to expected red shift, the Raman line shape shows a substantial blue shift, which is attributed to size dependent compressive stress in the nanoparticles. The calculated Raman line shape for the stressed nanoparticles fits well to data. The sizes of Si nanoparticles obtained using complex frequency model are consistent with the size estimated from the fitting of confined optical phonon line shapes and those found from X-ray diffraction and TEM.

Studies of local structure at Zr sites in pressure amorphized zirconium tungstate.

Amorphous to crystalline transition in pressure quenched Zr(0.5)Hf(0.5)W(2)O(8) has been studied with respect to local structures of ZrO(6) using the perturbed angular correlation technique. In an untreated crystalline sample close to 0.7 fraction of the probe atoms occupy Zr sites of regular ZrO(6) while the remaining three fractions are understood to be associated with contracted and distorted octahedra. The existence of six distinct ZrO(6) could be deduced based on perturbed angular correlation studies in the pressure amorphized sample. In the amorphous sample these ZrO(6) are associated with appreciable octahedral distortions. Isochronal annealing measurements show that these octahedra remain structurally quite stable up to 800 K. Values of quadrupole frequencies tend to become close to those experienced by probe atoms in a crystalline sample for annealing at 870 K, implying that around this temperature there is an onset of amorphous to crystalline transition. Complete restoration of quadrupole parameters to those of the untreated crystalline sample is seen subsequent to annealing at 975 K.

Spectroscopic characterization of nanocrystalline chromium nitride (CrN).

Nanocrystalline chromiuim nitride has been synthesised by direct gas phase nitridation of nanocrystalline chromia at 1100 degrees C in ammonia-atmosphere. XRD of this material showed formation of single phase CrN with particle size around 20 nm. AFM studies showed particle distribution along with some soft agglomerated nanostructures. Nanocrystalline Cr2O3 and partially-as well as fully--converted nanocrystalline CrN were also investigated using various spectroscopic techniques like XPS, FT-IR, and Raman for gaining insight into the conversion pathways. Spectroscopic investigations of these materials clearly indicate that complete conversion of CrN occurs by nitriding at 1100 degrees C for 4 hrs. The salient spectroscopic features of these nanocrystalline materials with respect to their microcrystalline counterparts are discussed.