Residual concentrations of antimicrobial growth promoters in poultry litter favour plasmid conjugation among Escherichia coli.

Considering that plasmid conjugation is a major driver for the dissemination of antimicrobial resistance in bacteria, this study aimed to investigate the effects of residual concentrations of antimicrobial growth promoters (AGPs) in poultry litter on the frequencies of IncFII-FIB plasmid conjugation among Escherichia coli organisms. A 2 × 5 factorial trial was performed in vitro, using two types of litter materials (sugarcane bagasse and wood shavings) and five treatments of litter: non-treated (CON), herbal alkaloid sanguinarine (SANG), AGPs monensin (MON), lincomycin (LCM) and virginiamycin (VIR). E. coli H2332 and E. coli J62 were used as donor and recipient strains, respectively. The presence of residues of monensin, lincomycin and virginiamycin increased the frequency of plasmid conjugation among E. coli in both types of litter materials. On the contrary, sanguinarine significantly reduced the frequency of conjugation among E. coli in sugarcane bagasse litter. The conjugation frequencies were significantly higher in wood shavings compared with sugarcane bagasse only in the presence of AGPs. Considering that the presence of AGPs in the litter can increase the conjugation of IncFII-FIB plasmids carrying antimicrobial resistance genes, the real impact of this phenomenon on the dissemination of antimicrobial resistant bacteria in the poultry production chain must be investigated.

Artificial intelligence and high-resolution anoscopy: automatic identification of anal squamous cell carcinoma precursors using a convolutional neural network.

BACKGROUND: High-resolution anoscopy (HRA) is the gold standard for detecting anal squamous cell cancer (ASCC) precursors. Although it is superior to other diagnostic methods, particularly cytology, the visual identification of areas suspected of having high-grade squamous intraepithelial lesions remains difficult. Convolutional neural networks (CNNs) have shown great potential for assessing endoscopic images. The aim of the present study was to develop a CNN-based system for automatic detection and differentiation of HSIL versus LSIL in HRA images. METHODS: A CNN was developed based on 78 HRA exams from a total of 71 patients who underwent HRA at a single high-volume center (GH Paris Saint-Joseph, Paris, France) between January 2021 and January 2022. A total of 5026 images were included, 1517 images containing HSIL and 3509 LSIL. A training dataset comprising 90% of the total pool of images was defined for the development of the network. The performance of the CNN was evaluated using an independent testing dataset comprising the remaining 10%. The sensitivity, specificity, accuracy, positive and negative predictive values, and area under the curve (AUC) were calculated. RESULTS: The algorithm was optimized for the automatic detection of HSIL and its differentiation from LSIL. Our model had an overall accuracy of 90.3%. The CNN had sensitivity, specificity, positive and negative predictive values of 91.4%, 89.7%, 80.9%, and 95.6%, respectively. The area under the curve was 0.97. CONCLUSIONS: The CNN architecture for application to HRA accurately detected precursors of squamous anal cancer. Further development and implementation of these tools in clinical practice may significantly modify the management of these patients.

Deciphering the role of ttrA and pduA genes for Salmonella enterica serovars in a chicken infection model.

Salmonella enterica serovars use self-induced intestinal inflammation to increase electron acceptor availability and to obtain a growth advantage in the host gut. There is evidence suggesting that the ability of Salmonella to use tetrathionate and 1,2-propanediol provides an advantage in murine infection. Thus, we present here the first study to evaluate both systemic infection and faecal excretion in commercial poultry challenged by Salmonella Enteritidis (SE) and S. Typhimurium (STM) harbouring deletions in ttrA and pduA genes, which are crucial to the metabolism of tetrathionate and 1,2-propanediol, respectively. Mutant strains were excreted at higher rates when compared to the wild-type strains. The highest rates were observed with white egg-layer and brown egg-layer chicks (67.5%), and broiler chicks (56.7%) challenged by SEΔttrAΔpduA, and brown egg-layer chicks (64.8%) challenged by STMΔttrAΔpduA. SEΔttrAΔpduA presented higher bacterial counts in the liver and spleen of the three chicken lineages and caecal contents from the broiler chickens, whereas STMΔttrAΔpduA presented higher counts in the liver and spleen of the broiler and brown-egg chickens for 28 days post-infection (P < 0.05). The ttrA and pduA genes do not appear to be major virulence determinants in faecal excretion or invasiveness for SE and STM in chickens. RESEARCH HIGHLIGHTSttrA and pudA do not impair gut colonization or systemic infection in chicks.Mutant strains were present in higher numbers in broilers than in laying chicks.Mutants of SE and STM showed greater pathogenicity in broiler chicks than layers.

Artificial intelligence and colon capsule endoscopy: development of an automated diagnostic system of protruding lesions in colon capsule endoscopy.

BACKGROUND: Colon capsule endoscopy (CCE) is a minimally invasive alternative for patients unwilling to undergo conventional colonoscopy, or for whom the latter exam is contraindicated. This is particularly important in the setting of colorectal cancer screening. Nevertheless, these exams produce large numbers of images, and reading them is a monotonous and time-consuming task, with the risk of overlooking important lesions. The development of automated tools based on artificial intelligence (AI) technology may improve some of the drawbacks of this diagnostic instrument. METHODS: A database of CCE images was used for development of a Convolutional Neural Network (CNN) model. This database included anonymized images of patients with protruding lesions in the colon or patients with normal colonic mucosa or with other pathologic findings. A total of 3,387,259 frames from 24 CCE exams were retrospectively reviewed. For CNN development, 3640 images (860 protruding lesions and 2780 with normal mucosa or other findings) were ultimately extracted. Training and validation datasets were constructed for the development and testing of the CNN. RESULTS: The CNN detected protruding lesions with a sensitivity, specificity, positive and negative predictive values of 90.7, 92.6, 79.2 and 96.9%, respectively. The area under the receiver operating characteristic curve for detection of protruding lesions was 0.97. CONCLUSIONS: The deep learning algorithm we developed is capable of accurately detecting protruding lesions. The application of AI technology to CCE may increase its diagnostic accuracy and acceptance for screening of colorectal neoplasia.

Swine as reservoirs of zoonotic borderline oxacillin-resistant Staphylococcus aureus ST398.

Methicillin resistance mediated by the mecA gene in Staphylococcus aureus, also known as "true MRSA", is typically associated with high oxacillin MIC values (≥8 mg/L). Because non-mecA-mediated oxacillin resistant S. aureus phenotypes can also cause hard-to-treat diseases in humans, their misidentification as methicillin-susceptible S. aureus strains (MSSA) can compromise the efficiency of the antimicrobial therapy. These strains have been refereed as Borderline Oxacillin-Resistant S. aureus (BORSA) but their characterization and role in clinical microbiology have been neglected. Considering the increasing importance of livestock-associated methicillin-resistant S. aureus ST398 (LA-MRSA) as an emerging zoonotic pathogen worldwide, this study aimed to report the genomic context of oxacillin resistance in porcine S. aureus ST398 strains. S. aureus isolates were recovered from asymptomatic pigs from three herds. Oxacillin MIC values ranged from 4 to 32 mg/L. MALDI-TOF-confirmed isolates were screened for mecA and mecC by PCR and genotyped by means of PFGE and Rep-PCR. Seven isolates were whole genome sequenced. None of the isolates harbored the mecA gene or its variants. Although all seven sequenced isolates belonged to one sequence type (ST398), two different spa types (t571 and t1471) were identified. All isolates harbored conserved blaZ gene operon and no mutations on genes encoding for penicillin-binding-proteins were detected. Genes conferring resistance against other drugs such as aminoglycosides, chloramphenicol, macrolide, lincosamide and streptogramin (MLS), tetracycline and trimethoprim were also detected. Isolates also harbored virulence genes encoding for adhesins (icaA; icaB; icaC; icaD; icaR), toxins (hlgA; hlgB; hlgC; luk-PV) and protease (aur). Pigs can serve as reservoirs of non-mecA-mediated oxacillin-resistant ST398 strains potentially pathogenic to humans. Considering that mecA has been the main target to screen methicillin-resistant staphylococci, the occurrence of BORSA phenotypes is probably underestimated in livestock.

The importance of ultrasound findings in the study of anal pain.

OBJECTIVE: Endoanal ultrasonography can detect organic causes of anal pain without pathology on physical examination. The aim of this study is to evaluate the importance of endoanal ultrasonography in the diagnosis and therapeutic management of idiopathic and functional anal pain. MATERIAL AND METHODS: Retrospective study, between 15 March 2005 and 15 June 2008, of all patients with proctalgia and normal examination or with alterations not responsible for anal pain at proctologic exam that have undergone an endoanal ultrasonography. RESULTS: A total of 90 patients were analyzed, with a mean age of 50.5 years, 58% were female. Twenty-three patients had functional anal pain clinic criteria. Endoanal ultrasonography revealed alterations in 49% of patients. The primary findings were changes in sphincters in 14 patients, followed by anal sepsis in 12 patients, anal fissure in 10 patients, perirectal lesions in 6 patients and ulcer of the anal canal in 2 patients. Of the patients with sphincter defects, 5 patients had criteria of chronic anal pain. In this group of patients, no differences were found in manometric and defecographic results between the different ultrasound abnormalities. CONCLUSIONS: The endoanal ultrasonography detected occult organic lesions to proctologic examination, in half the patients with anal pain. Ultrasound abnormalities were found in 22% of patients with functional anal pain. However, there was no correlation between ultrasound findings and physiological studies, and therefore could not find etiological or pathogenic factors of functional anal pain.

Evaluation of propanediol and cobalamin metabolism in the intestinal colonization and systemic invasion of Salmonella Enteritidis in laying hens / [Avaliação do metabolismo do propanodiol e da cobalamina na colonização intestinal e na infecção sistêmica de Salmonella Enteritidis em poedeiras]

Embora Salmonella Enteritidis (SE) seja capaz de metabolizar 1,2-propanodiol (1,2-Pd), utilizado como fonte de carbono e de energia ao longo de uma rota dependente de vitamina B12, a importância deste composto na infeção de Gallus gallus domesticus por SE permanece desconhecida. No presente estudo, foram construídos um mutante de SE sem os genes pduCDE, que codifica a propanodiol desidratase (Pdu), e outro contendo as deleções no pduCDE e também nos genes cobS e cbiA, responsáveis pela síntese de vitamina B12. Em seguida, avaliou-se a importância do metabolismo do 1,2-Pd em SE para colonização intestinal de infecção sistêmica de poedeiras comerciais. As estirpes mutantes de SE foram capazes de colonizar o intestino, de serem excretadas nas fezes e de invadir o baço e o fígado na mesma intensidade que a estirpe selvagem, o que sugere que os produtos dos genes pduC, pduD, pduE, cobS e cbiA não são essenciais durante infecção por Salmonella Enteritidis nessa espécie.(AU)

Foodborne outbreaks in northern Portugal, 2002.

In October 2001, foodborne outbreaks (FBO) were included in the Portuguese alert and response surveillance system. Accordingly, the northern regional health authority (Delegado Regional de Saude do Norte--DRSN) began a surveillance programme of foodborne outbreaks. This report is a brief description of data generated from this programme in 2002. For each foodborne outbreak the local health authority (Delegado de Saude Concelhio--DSC) produced a written report. Fifty-nine percent of the 27 FBOs studied by DSCs during 2002 were reported within 72 hours after the date of onset. Five hundred and seventy seven people became ill, 9.6% of the patients were admitted to hospital, and no deaths were reported. The aetiological agent was identified from patients in 63% of FBOs, and in food items in 18.5% of the situations. Salmonella enterica was responsible for 73.7% of the outbreaks in which the agent was laboratory confirmed. Meals implicated in the outbreak were mainly prepared in restaurants and private homes (75.0% of FBO). Inadequate processing, preparing or handling of foods were the contributing factors more often reported by the DSC. We believe that epidemiological surveillance and control of FBO must be reinforced in Portugal as part of a wider strategy to promote food safety.

Anal tonometry: a quick method of anal manometry.

Evaluation of anal sphincter tonic activity is important in the proctologic clinic. However, manometric techniques are expensive, complex, and only available in some centers. Because there is often an in-office need for having objective measurements of anal tonic activity, in our clinic we introduced a simple method for measurement of anal pressures. This method is based on the flow of air in an open circuit by using a rubber probe with a side opening at one end. Pressure is assessed by an ordinary manometric gauge for arterial pressure. With this simple instrument, the following parameters are measured: 1) anal resting pressure, 2) squeeze pressure, 3) functional length of the anal canal, and 4) descent of the perineum on staining. After testing the technique in 100 healthy persons, it was applied to 130 patients with several proctologic disorders. Differences in pressures were found between controls and patients with anal fissure (high resting pressures), and patients with anal incontinence (low resting and/or squeeze pressures). A correlation was also found between the descending perineum measured by this method and by defecography. This simple instrument is useful in the office as the first approach to the function of the anal sphincters and the pelvic floor. Nowadays, so-called anal tonometry is part of the proctologic examination in our department, because it is simple, reliable, and takes only a few minutes.