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1.
BMC Gastroenterol ; 22(1): 56, 2022 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-35144537

RESUMEN

BACKGROUND: Type 2 isolated dextrogastria in conjunction with protrusion of the right hemidiaphragm and hiatal hernia is an uncommon anomaly among all transpositions of the viscera. Clear diagnosis is not straightforward in such cases both clinically and with various imaging techniques leaving often only laparotomy for diagnosis. CASE PRESENTATION: Here, we discuss the case of a so far asymptomatic 19-year-old male, who had a 3-month history of abdominal pain and 2 days of vomiting with absolute constipation, and reduced air entry in the base of the right lung. A large air fluid level was found in the right lower hemithorax, furthermore, a loss of the normal diaphragmatic outline, and paucity of the bowel gases in the rest of the abdomen. Computer tomography with contrast was suggestive of loss of right lung volume, with stomach and bowel loops herniating into the right hemithorax and compressive atelactatic changes in the adjacent lung alongside an enlarged liver. A barium test showed the stomach fundus and body posteriorly positioned, while both duodenal bulb loops and the duodeno-jejunal junction alongside the small and large bowels were detected in their normal positions. CONCLUSION: In case of visceral transpositions, routine diagnostic blood and radiological tests may lead the health care provider to misdiagnosis. It is necessary, in particular when surgery is required, to carefully elucidate the organ anomaly. The use of additional imaging and radiological methods may be called for; CT scan and a barium test were critical here. This is the first case of isolated dextrogastria with eventration of right hemidiaphragm and hiatal hernia reported from Pakistan providing insights for diagnostic procedures.


Asunto(s)
Hernia Hiatal , Situs Inversus , Abdomen , Adulto , Hernia Hiatal/complicaciones , Hernia Hiatal/diagnóstico por imagen , Humanos , Masculino , Radiografía , Estómago/diagnóstico por imagen , Adulto Joven
2.
BMC Infect Dis ; 22(1): 593, 2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35790903

RESUMEN

BACKGROUND: In low- and middle-income countries (LMIC) Staphylococcus aureus is regarded as one of the leading bacterial causes of neonatal sepsis, however there is limited knowledge on the species diversity and antimicrobial resistance caused by Gram-positive bacteria (GPB). METHODS: We characterised GPB isolates from neonatal blood cultures from LMICs in Africa (Ethiopia, Nigeria, Rwanda, and South Africa) and South-Asia (Bangladesh and Pakistan) between 2015-2017. We determined minimum inhibitory concentrations and performed whole genome sequencing (WGS) on Staphylococci isolates recovered and clinical data collected related to the onset of sepsis and the outcome of the neonate up to 60 days of age. RESULTS: From the isolates recovered from blood cultures, Staphylococci species were most frequently identified. Out of 100 S. aureus isolates sequenced, 18 different sequence types (ST) were found which unveiled two small epidemiological clusters caused by methicillin resistant S. aureus (MRSA) in Pakistan (ST8) and South Africa (ST5), both with high mortality (n = 6/17). One-third of S. aureus was MRSA, with methicillin resistance also detected in Staphylococcus epidermidis, Staphylococcus haemolyticus and Mammaliicoccus sciuri. Through additional WGS analysis we report a cluster of M. sciuri in Pakistan identified between July-November 2017. CONCLUSIONS: In total we identified 14 different GPB bacterial species, however Staphylococci was dominant. These findings highlight the need of a prospective genomic epidemiology study to comprehensively assess the true burden of GPB neonatal sepsis focusing specifically on mechanisms of resistance and virulence across species and in relation to neonatal outcome.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Sepsis Neonatal , Cultivo de Sangre , Países en Desarrollo , Etiopía , Humanos , Recién Nacido , Sepsis Neonatal/epidemiología , Estudios Prospectivos , Staphylococcus aureus/genética
3.
Molecules ; 27(9)2022 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-35566209

RESUMEN

BACKGROUND: A gastric cancer (GC) diagnosis relies on histopathology. Endoscopy rates are increasing. Helicobacter pylori infection is a major GC risk factor. In an effort to elucidate abundant blood biomarkers, and potentially reduce the number of diagnostic surgical interventions, we investigated sera and biopsies from a cohort of 219 H. pylori positive and negative patients diagnosed with GC, gastritis, and ulcers. This allowed the comparative investigation of the different gastroduodenal diseases, and the exclusion of protein changes resulting from bacterial infection or inflammation of the gastric mucosa when searching for GC-dependent proteins. METHODS: High-definition mass spectrometry-based expression analysis of tryptically digested proteins was performed, followed by multivariate statistical and network analyses for the different disease groups, with respect to H. pylori infection status. Significantly regulated proteins differing more than two-fold between groups were shortlisted, and their role in gastritis and GC discussed. RESULTS: We present data of comparative protein analyses of biopsies and sera from patients suffering from mild to advanced gastritis, ulcers, and early to advanced GC, in conjunction with a wealth of metadata, clinical information, histopathological evaluation, and H. pylori infection status. We used samples from pre-malignant stages to extract prospective serum markers for early-stage GC, and present a 29-protein marker panel containing, amongst others, integrin ß-6 and glutathione peroxidase. Furthermore, ten serum markers specific for advanced GC, independent of H. pylori infection, are provided. They include CRP, protein S100A9, and kallistatin. The majority of these proteins were previously discussed in the context of cancer or GC. In addition, we detected hypoalbuminemia and increased fibrinogen serum levels in gastritis. CONCLUSION: Two protein panels were suggested for the development of multiplex tests for GC serum diagnostics. For most of the elements contained in these panels, individual commercial tests are available. Thus, we envision the design of multi-protein assays, incorporating several to all of the panel members, in order to gain a level of specificity that cannot be achieved by testing a single protein alone. As their development and validation will take time, gastritis diagnosis based on the fibrinogen to albumin serum ratio may be a quick way forward. Its determination at the primary/secondary care level for early diagnosis could significantly reduce the number of referrals to endoscopy. Preventive measures are in high demand. The protein marker panels presented in this work will contribute to improved GC diagnostics, once they have been transferred from a research result to a practical tool.


Asunto(s)
Gastritis , Infecciones por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Biomarcadores/metabolismo , Detección Precoz del Cáncer , Fibrinógeno/metabolismo , Mucosa Gástrica/patología , Gastritis/diagnóstico , Gastritis/metabolismo , Infecciones por Helicobacter/complicaciones , Humanos , Estudios Prospectivos , Neoplasias Gástricas/metabolismo , Úlcera/patología
4.
Molecules ; 27(17)2022 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-36080177

RESUMEN

(1) Background: Gastric cancer (GC) is the fourth leading cause of cancer-related deaths worldwide. Helicobacter pylori infection is a major risk factor, but other microbial species may also be involved. In the context of an earlier proteomics study of serum and biopsies of patients with gastroduodenal diseases, we explored here a simplified microbiome in these biopsies (H. pylori, Acinetobacter baumannii, Escherichia coli, Fusobacterium nucleatum, Bacteroides fragilis) on the protein level. (2) Methods: A cohort of 75 patients was divided into groups with respect to the findings of the normal gastric mucosa (NGM) and gastroduodenal disorders such as gastritis, ulcer, and gastric cancer (GC). The H. pylori infection status was determined. The protein expression analysis of the biopsy samples was carried out using high-definition mass spectrometry of the tryptic digest (label-free data-independent quantification and statistical analysis). (3) Results: The total of 304 bacterial protein matches were detected based on two or more peptide hits. Significantly regulated microbial proteins like virulence factor type IV secretion system protein CagE from H. pylori were found with more abundance in gastritis than in GC or NGM. This finding could reflect the increased microbial involvement in mucosa inflammation in line with current hypotheses. Abundant proteins across species were heat shock proteins and elongation factors. (4) Conclusions: Next to the bulk of human proteins, a number of species-specific bacterial proteins were detected in stomach biopsies of patients with gastroduodenal diseases, some of which, like those expressed by the cag pathogenicity island, may provide gateways to disease prevention without antibacterial intervention in order to reduce antibiotic resistance.


Asunto(s)
Gastritis , Infecciones por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Úlcera Gástrica , Proteínas Bacterianas , Biopsia , Mucosa Gástrica/patología , Gastritis/patología , Infecciones por Helicobacter/microbiología , Humanos , Neoplasias Gástricas/patología , Úlcera Gástrica/patología , Úlcera/patología
5.
Women Health ; 61(9): 867-871, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34569446

RESUMEN

Metastatic spread of invasive lobular breast carcinoma to stomach is rare especially before diagnosis of primary breast cancer. Incorrect diagnosis might result in delay of appropriate treatment for breast cancer. Recognition of this possibility enables better clinical management. A 62-year-old female presented with upper gastrointestinal symptoms and weight loss and was referred to a gastroenterologist for investigation. At the time of initial diagnosis of stomach cancer, patient was asymptomatic for breast cancer. Multiple gastric biopsies taken showed features suspicious of metastatic breast cancer. Consequently, the initial provisional diagnosis of stomach cancer changed into metastatic invasive lobular breast carcinoma. These findings were corroborated radiologically. The patient was treated with letrozole and zoledronic acid as first-line therapy for one year. Residual metastatic breast cancer was present in the gastric mucosa. The patient was treated with endocrine therapy containing ribociclib and treatment was ineffective confirmed by PET-CT scan. But her symptoms have resolved completely despite her presentation with stage IV. We present rare case of initial presentation of gastric metastasis before diagnosis of a primary invasive lobular breast carcinoma. Correct diagnosis and appropriate treatment were accomplished through initial clinical suspicion, accurate histological examination, and endoscopy together with analysis of disease-specific biomarkers.


Asunto(s)
Neoplasias de la Mama , Carcinoma Lobular , Neoplasias de la Mama/diagnóstico , Carcinoma Lobular/diagnóstico por imagen , Femenino , Humanos , Persona de Mediana Edad , Pakistán , Tomografía Computarizada por Tomografía de Emisión de Positrones , Estómago
6.
Pak J Med Sci ; 36(2): 136-140, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32063947

RESUMEN

OBJECTIVE: To study the prevalence of inducible clindamycin along with vancomycin and methicillin resistance and assessment of hyper variable region (HVR) of mecA gene among different clinical isolates of Staphylococcus spp. METHODS: A total of 176 clinical isolates of Staphylococci were collected from Pakistan Institute of Medical Sciences (PIMS), Islamabad during 2014-2015. The sample sources were pus, blood, urine, sputum, tracheal secretions and tissue fluids. Bacterial identification was done by colony morphology and biochemical tests. Kirby-Bauer disc-diffusion method was carried out to assess the susceptibility against different antibiotics. Minimal inhibitory concentrations (MICs) were done for vancomycin resistance. Double Disk Diffusion test (D-test) was used to detect the clindamycin inducible resistance. PCR was performed to detect erm(C), mecA and HVR genes. RESULTS: Clindamycin inducible resistance among Staphylococcal isolates was found to be 7%, whereas in S. aureus it was 4%, and in coagulase negative Staphylococci (CoNS) it was 11%. The highest resistance was observed against fosfomycin, fusidic acid and cefoxitin. Vancomycin resistance was observed in 23 isolates (13%) of Staphylococci. erm(C), mecA and HVR genes were found in 18%, 50% and 42% respectively. CONCLUSIONS: D-test must be performed routinely to avoid clindamycin failure. A high level of resistance against vancomycin in Staphylococcal isolates is a concern for public health.

7.
J Pak Med Assoc ; 69(5): 666-671, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31105285

RESUMEN

OBJECTIVE: To assess the biofilm formation in clinical and environmental isolates of Pseudomonas aeruginosa and to evaluate the hydrodynamics in microtiter plate assay and compare it with conventional assays for biofilm formation. METHODS: The cross-sectional study was conducted at the Department of Microbiology, Quaid-i-Azam University, Islamabad, Pakistan, in 2013-14, while the computational work was done at the National University of Science and Technology, Islamabad. The study comprised environmental and clinical isolates of pseudomonas aeruginosa. Pseudomonas citramide agar was used as a selective media, and further confirmation was done by biochemical tests. Biofilm formation was assessed by Congo red assay, air liquid interfaceassay and microtiter plate assay. Computational Fluid Dynamics (CFD) simulations were also used to improve the microtiter plate assay for biofilm formation assessment. Polymerase chain reaction was used for screening of pelA and pelG genes. RESULTS: Of the 50 isolates, 25(50%) each were environmental and clinical. The number of biofilm producers observed in Congo red assay, air liquid interface assay and microtiter plate assay were 7(14%), 15(30%) and 30(60%) respectively. Biofilm former gene pelA was observed in 22(44%) isolates while 36(72%) isolates showed the presence of pelG gene. CONCLUSIONS: Microtiter plate assay was found to be a reliable method to detect biofilm forming pseudomonas aeruginosa isolates which further provides a base for development of methods to detect biofilms readily and accurately.


Asunto(s)
Técnicas Bacteriológicas/métodos , Biopelículas/crecimiento & desarrollo , Pseudomonas aeruginosa/fisiología , Simulación por Computador , Humanos , Hidrodinámica , Pseudomonas aeruginosa/genética
9.
J Antimicrob Chemother ; 73(7): 1781-1785, 2018 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-29648612

RESUMEN

Objectives: To discover the Escherichia coli STs and associated resistance mechanisms in the community in Islamabad, Pakistan by analysis of E. coli isolates in sewage. Methods: One hundred and ten E. coli were isolated from sewage across the city of Islamabad without antibiotic bias and confirmed as E. coli by MALDI-TOF MS. Isolates were characterized by fumC/fimH (CH) typing and core-genome MLST. Resistance mechanisms, virulence genes, phylotypes and plasmid incompatibility types were determined in a subset of isolates by in silico analysis. The genomic position of blaCTX-M-15 was determined using S1-PFGE, probing and Nanopore MinION sequencing. Results and conclusions: The most prevalent STs were ST394, ST10 and ST648, accounting for 39% of all isolates collected and were found at many sites across Islamabad. Carbapenemase genes were absent and only a single isolate of ST131 was found. The most prevalent resistance mechanisms were qnrS1 and blaCTX-M-15, with blaCTX-M-15 penetrating many STs and found in 31% of all collected isolates. However, the majority of the successful STs were blaCTX-M-15 negative indicating that resistance is not the main driver of prevalence. Twenty-three percent of blaCTX-M-15 genes were chromosomally encoded and large ISEcp1-mediated insertions included qnrS1 and several plasmid genes. In all chromosomally encoded isolates no plasmid copies of blaCTX-M-15 were found. The most prevalent ST (ST394) contained many enteroaggregative E. coli virulence genes and the fimH30 variant allele previously linked to the success of ST131.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Aguas del Alcantarillado/microbiología , Asia , Proteínas Bacterianas/genética , Técnicas de Tipificación Bacteriana , Electroforesis en Gel de Campo Pulsado , Escherichia coli/enzimología , Europa (Continente) , Genoma Bacteriano , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Pakistán , Plásmidos , Factores de Virulencia/genética , beta-Lactamasas/genética
10.
Pak J Med Sci ; 34(3): 633-637, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30034429

RESUMEN

OBJECTIVE: To determine the role of icaAD and agr genes in biofilm formation and evaluate the consistency of two phenotypic methods for biofilm measurement. METHODS: A total of 81 clinical S. aureus strains were included and analyzed for biofilm formation by two methods. The microtitration plate method was optimized using computational fluid dynamics and compared with the Congo red assay. The genes for icaAD and agr were detected using PCR. RESULTS: Of 81 isolates, biofilm production was detected in 43% isolates using Congo red method while microtiter plate assay showed biofilm production in 92% isolates. Both methods showed correlation in 30% isolates. PCR detection showed icaAD gene in 42 (52%) isolates. Out of 81 S. aureus isolates 65 strains (80%) contained agr while 16 (20%) strains were non-typeable. CONCLUSIONS: In conclusion, biofilm production was observed for both agr positive and agr negative isolates. Furthermore, the presence of icaAD genes was not associated with all biofilm producing strains as some strains negative for icaAD genes displayed biofilm production.

11.
Helicobacter ; 19(5): 387-99, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24827414

RESUMEN

BACKGROUND: Antibiotic resistance in Helicobacter pylori contributes to failure in eradicating the infection and is most often due to point and missense mutations in a few key genes. METHODS: The antibiotic susceptibility profiles of H. pylori isolates from 46 Pakistani patients were determined by Etest. Resistance and pathogenicity genes were amplified, and sequences were analyzed to determine the presence of mutations. RESULTS: A high percentage of isolates (73.9%) were resistant to metronidazole (MTZ), with considerable resistance to clarithromycin (CLR; 47.8%) and amoxicillin (AML; 54.3%) also observed. Relatively few isolates were resistant to tetracycline (TET; 4.3%) or to ciprofloxacin (CIP; 13%). However, most isolates (n = 43) exhibited resistance to one or more antibiotics. MTZ-resistant isolates contained missense mutations in oxygen-independent NADPH nitroreductase (RdxA; 8 mutations found) and NADH flavin oxidoreductase (FrxA; 4 mutations found). In the 23S rRNA gene, responsible for CLR resistance, a new point mutation (A2181G) and 4 previously reported mutations were identified. Pathogenicity genes cagA, dupA, and vacA s1a/m1 were detected frequently in isolates which were also found to be resistant to MTZ, CLR, and AML. A high percentage of CagA and VacA seropositivity was also observed in these patients. Phylogenetic analysis of partial sequences showed uniform distribution of the 3' region of cagA throughout the tree. CONCLUSIONS: We have identified H. pylori isolates in Pakistan which harbor pathogenicity genes and worrying antibiotic resistance profiles as a result of having acquired multiple point and missense mutations. H. pylori eradication regimens should therefore be reevaluated in this setting.


Asunto(s)
Farmacorresistencia Bacteriana , Infecciones por Helicobacter/epidemiología , Helicobacter pylori/aislamiento & purificación , Adulto , Anciano , Anciano de 80 o más Años , Proteínas Bacterianas/genética , Secuencia de Bases , Claritromicina/farmacología , Estudios de Cohortes , Femenino , Infecciones por Helicobacter/microbiología , Helicobacter pylori/efectos de los fármacos , Helicobacter pylori/genética , Helicobacter pylori/patogenicidad , Humanos , Masculino , Metronidazol/farmacología , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Datos de Secuencia Molecular , Mutación , Pakistán/epidemiología , Filogenia , Análisis de Secuencia de ADN , Virulencia , Adulto Joven
12.
Hepatogastroenterology ; 61(129): 125-8, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24895807

RESUMEN

BACKGROUND/AIMS: 13C urea breath test (13C UBT) is used to detect Helicbacter (H.) pylori in gastric mucosa. There are controversial results regarding associations of 13C UBT values with histopathological grades. We designed this study to correlate 13C UBT values with different histopathological grades in our local setting. METHODOLOGY: 13CO2/12CO2 ratio for 13C UBT was analyzed using mass spectrometry and histopatholgical grades were scored by updated Sydney System. RESULTS: 13C UBT values of H. pylori positive patients at different times (T10-T60) were higher as compared to negative patients. Significant positive correlation of 13C UBT values at T30 with different scores of H. pylori load (r = 0.277, p = 0.037) was observed. Associations of the mean 13C UBT values with neutrophil infiltration (p = 0.214), mononuclear cell infiltration (p = 0.648), atrophy (p= 0.620), atypia (p = 0.057) and metaplasia scores (p = 0.718) were found to be nonsignificant. H. pylori load significantly correlated with neutrophil infiltration and atrophy with exception of mononuclear cell infiltration, atypia and metaplasia. CONCLUSIONS: In the present analysis, significant positive correlation was observed between 13C UBT values and H. pylori load that would be helpful in qauntification of H. pylori in our local setting.


Asunto(s)
Pruebas Respiratorias/métodos , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/microbiología , Helicobacter pylori , Adulto , Anciano , Anciano de 80 o más Años , Biopsia , Isótopos de Carbono/metabolismo , Gastroscopía , Humanos , Persona de Mediana Edad , Urea/metabolismo
13.
Pak J Med Sci ; 30(1): 172-6, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24639855

RESUMEN

OBJECTIVE: The accessory gene regulator (agr) locus in Staphylococcus aureus (S. aureus) is a global regulator of quorum sensing and controls the production of virulence factors. This study was carried out to investigate the agr specific groups both in methicillin resistant and sensitive Staphylococcus aureus (MRSA and MSSA) and their relation with antibiotic resistance. METHODS: A total of 90 clinical S. aureus isolates were studied from two tertiary care hospitals. The isolates were identified by standard biochemical tests. Methicillin resistance was confirmed by oxacillin and cefoxitin resistance. Multiplex PCR was used to determine the agr groups. RESULTS: MRSA prevalence was found to be 53.3%.The agr groups' distribution in MRSA was as follows: 22 (45.8%) belonged to group I, 14 (29.1%) belonged to group III and 2 (4.1%) belonged to group II. agrIV was not detected in MRSA. For 17 isolates, the agr group was not detected.agr III isolates showed higher antibiotic resistance than agrI isolates except in case of oxacillin and linezolid. CONCLUSIONS: Strict infection control policy and antibiotic guidelines should be adopted to control the problem of MRSA. Higher prevalence of agr I and agr III shows that they are dominant agr groups of our area.

14.
Nat Commun ; 15(1): 2758, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38553439

RESUMEN

Hospital surfaces can harbour bacterial pathogens, which may disseminate and cause nosocomial infections, contributing towards mortality in low- and middle-income countries (LMICs). During the BARNARDS study, hospital surfaces from neonatal wards were sampled to assess the degree of environmental surface and patient care equipment colonisation by Gram-negative bacteria (GNB) carrying antibiotic resistance genes (ARGs). Here, we perform PCR screening for extended-spectrum ß-lactamases (blaCTX-M-15) and carbapenemases (blaNDM, blaOXA-48-like and blaKPC), MALDI-TOF MS identification of GNB carrying ARGs, and further analysis by whole genome sequencing of bacterial isolates. We determine presence of consistently dominant clones and their relatedness to strains causing neonatal sepsis. Higher prevalence of carbapenemases is observed in Pakistan, Bangladesh, and Ethiopia, compared to other countries, and are mostly found in surfaces near the sink drain. Klebsiella pneumoniae, Enterobacter hormaechei, Acinetobacter baumannii, Serratia marcescens and Leclercia adecarboxylata are dominant; ST15 K. pneumoniae is identified from the same ward on multiple occasions suggesting clonal persistence within the same environment, and is found to be identical to isolates causing neonatal sepsis in Pakistan over similar time periods. Our data suggests persistence of dominant clones across multiple time points, highlighting the need for assessment of Infection Prevention and Control guidelines.


Asunto(s)
Países en Desarrollo , Sepsis Neonatal , Recién Nacido , Humanos , beta-Lactamasas/genética , Proteínas Bacterianas/genética , Hospitales , Antibacterianos/farmacología , Klebsiella pneumoniae/genética , Bacterias Gramnegativas/genética , Pruebas de Sensibilidad Microbiana
15.
Proc Natl Acad Sci U S A ; 107(52): 22582-6, 2010 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-21149728

RESUMEN

Approximately half the human genome is composed of repetitive DNA sequences classified into microsatellites, minisatellites, tandem repeats, and dispersed repeats. These repetitive sequences have coevolved within the genome but little is known about their potential interactions. Trinucleotide repeats (TNRs) are a subclass of microsatellites that are implicated in human disease. Expansion of CAG·CTG TNRs is responsible for Huntington disease, myotonic dystrophy, and a number of spinocerebellar ataxias. In yeast DNA double-strand break (DSB) formation has been proposed to be associated with instability and chromosome fragility at these sites and replication fork reversal (RFR) to be involved either in promoting or in preventing instability. However, the molecular basis for chromosome fragility of repetitive DNA remains poorly understood. Here we show that a CAG·CTG TNR array stimulates instability at a 275-bp tandem repeat located 6.3 kb away on the Escherichia coli chromosome. Remarkably, this stimulation is independent of both DNA double-strand break repair (DSBR) and RFR but is dependent on a functional mismatch repair (MMR) system. Our results provide a demonstration, in a simple model system, that MMR at one type of repetitive DNA has the potential to influence the stability of another. Furthermore, the mechanism of this stimulation places a limit on the universality of DSBR or RFR models of instability and chromosome fragility at CAG·CTG TNR sequences. Instead, our data suggest that explanations of chromosome fragility should encompass the possibility of chromosome gaps formed during MMR.


Asunto(s)
Cromosomas Bacterianos/genética , Reparación del ADN , Escherichia coli/genética , Inestabilidad de Microsatélites , Secuencias Repetidas en Tándem/genética , Repeticiones de Trinucleótidos/genética , Secuencia de Bases , Roturas del ADN de Doble Cadena , ADN Bacteriano/genética , Humanos , Modelos Genéticos , Recombinación Genética , Expansión de Repetición de Trinucleótido/genética
16.
J Infect Public Health ; 16(6): 877-883, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37054501

RESUMEN

BACKGROUND: Antibiotic resistance in Staphylococci, particularly methicillin resistance is a major public health concern. While this problem has been reported from the clinical settings, its presence in non-clinical settings also needs to be investigated. The role of wildlife in carrying and disseminating the resistant strains has been established in different studies but its role in Pakistani environment has not been explored yet. To evaluate this, we investigated the carriage of antibiotic resistant Staphylococci in wild birds from Islamabad region. METHODOLOGY: Birds fecal matter were collected during September 2016-August 2017 from eight different environmental settings of Islamabad. Prevalence of Staphylococci, their susceptibility profile against eight classes of antibiotics through disc diffusion method, their SCCmec types, co-resistance of macrolide and cefoxitin through PCR assay and biofilm formation through microtitre plate assay were studied. RESULTS: Out of 320 birds feces collected, 394 Staphylococci were isolated, where 165 (42%) were resistant to at least one or two classes of antibiotics. High resistance was found against erythromycin (40%) and tetracycline (21%) while cefoxitin resistance was 18% and vancomycin resistance was only in 2%. One hundred and three (26%) isolates exhibited multi-drug resistance (MDR) pattern. mecA gene was detected in 45/70 (64%) cefoxitin resistant isolates. Community acquired methicillin resistant Staphylococci (CA-MRS) were 87% while Hospital acquired methicillin resistant Staphylococci (HA-MRS) were 40%. In the MRS isolates showing co-resistance to macrolides, mefA (69%) and ermC (50%) genes were more prevalent. Strong biofilm formation was observed in 90% of the MRS, of which 48% were methicillin resistant Staphylococcus aureus (MRSA) isolates while 52% were methicillin resistant coagulase negative Staphylococci (MRCoNS). CONCLUSION: Occurrence of methicillin resistant strains of Staphylococci in wild birds suggests their role in the carriage and dissemination of resistant strains into the environment. The findings of the study strongly recommend the monitoring of resistant bacteria in wild birds and wildlife.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Animales , Humanos , Cefoxitina/farmacología , Resistencia a la Meticilina , Animales Salvajes , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/veterinaria , Infecciones Estafilocócicas/microbiología , Staphylococcus/genética , Antibacterianos/farmacología , Macrólidos/farmacología , Pruebas de Sensibilidad Microbiana
17.
Life (Basel) ; 13(2)2023 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-36836901

RESUMEN

(1) Background: Untargeted mass spectrometry (MS)-based proteomic analysis is highly amenable to automation. Software algorithms translate raw spectral data into protein information obtained by a comparison to sequence databases. However, the technology has limitations, especially for analytes measured at the limit of detection. In a protein expression study of human gastric biopsies, the question arose whether or not it is possible, as well as sensible, to search for viral proteins in addition to those from the human host. (2) Methods: Experimental data-independent MS data were analyzed using protein sequences for oncoviruses, and BLAST analyses were performed to elucidate the level of sequence homology to host proteins. (3) Results: About one hundred viral proteins were assigned, but there was also up to 43% sequence homology to human proteins. (4) Conclusions: There are at least two reasons why the matches to viral proteins should be used with care. First, it is not plausible that large amounts of viral proteins should be present in human gastric biopsies, so the spectral quality of the peptides derived from viral proteins is likely low. As a consequence, the number of false assignments is high. Second, homologous peptides found both in human and virus proteomes contribute to matching errors. Thus, though shotgun proteomics raw data can technically be analyzed using any database, meaningful results cannot be always expected and a sanity check must be performed. Both instrumentation and bioinformatic processing in MS-based proteomics are continuously improving at lowering the limit of detection even further. Nevertheless, data output should always be controlled in order to avoid the over-interpretation of results.

18.
Microbiol Resour Announc ; 12(9): e0094522, 2023 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-37466328

RESUMEN

Lactiplantibacillus plantarum adapts to a wide range of ecological niches, including the human gut. Numerous health-promoting benefits have been associated with L. plantarum strains. Motivated for the development of human-origin target-based probiotics with known genetic markers, we report the draft genome sequence of human gut-associated Lactiplantibacillus plantarum subsp. plantarum HF43.

19.
Environ Int ; 178: 108089, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37441817

RESUMEN

Antimicrobial resistance (AMR) is a global threat to human and animal health and well-being. To understand AMR dynamics, it is important to monitor resistant bacteria and resistance genes in all relevant settings. However, while monitoring of AMR has been implemented in clinical and veterinary settings, comprehensive monitoring of AMR in the environment is almost completely lacking. Yet, the environmental dimension of AMR is critical for understanding the dissemination routes and selection of resistant microorganisms, as well as the human health risks related to environmental AMR. Here, we outline important knowledge gaps that impede implementation of environmental AMR monitoring. These include lack of knowledge of the 'normal' background levels of environmental AMR, definition of high-risk environments for transmission, and a poor understanding of the concentrations of antibiotics and other chemical agents that promote resistance selection. Furthermore, there is a lack of methods to detect resistance genes that are not already circulating among pathogens. We conclude that these knowledge gaps need to be addressed before routine monitoring for AMR in the environment can be implemented on a large scale. Yet, AMR monitoring data bridging different sectors is needed in order to fill these knowledge gaps, which means that some level of national, regional and global AMR surveillance in the environment must happen even without all scientific questions answered. With the possibilities opened up by rapidly advancing technologies, it is time to fill these knowledge gaps. Doing so will allow for specific actions against environmental AMR development and spread to pathogens and thereby safeguard the health and wellbeing of humans and animals.


Asunto(s)
Antibacterianos , Farmacorresistencia Bacteriana , Animales , Humanos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Farmacorresistencia Bacteriana/genética , Bacterias/genética , Monitoreo del Ambiente
20.
Antibiotics (Basel) ; 11(5)2022 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-35625279

RESUMEN

The WHO has classified carbapenem-resistant Enterobacteriaceae in most critical priority pathogens that pose a threat to human health. The present study investigated the prevalence of meropenem-resistant Escherichia coli (E. coli) in relation to its temporal variation in different seasons along with its resistance markers in sewage water. E. coli was selected on MacConkey agar containing meropenem (3 µg/mL). There were 27% of sites/sewage samples carrying meropenem-resistant E. coli. All E. coli were confirmed through the amplification of the uidA gene. All isolated E. coli were multidrug-resistant (MDR), and among them, 51% were extensively drug-resistant (XDR). An antibiogram determined against 15 antibiotics showed the highest resistance to ampicillin and cefotaxime (98% each) and lowest resistance to fosfomycin (2%). Phylogenetic groups and resistance gene analysis through PCR showed a significant co-occurrence of carbapenemases with extended spectrum beta lactamases (ESBLs), plasmid encoded quinolone, and colistin resistance genes. The higher number of resistance genes in E. coli isolates in community sewage indirectly indicate that these isolates circulate abundantly in the community.

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