Genomic analysis of fluoroquinolone-resistant Leclercia adecarboxylata carrying the ISKpn19-orf-qnrS1-ΔIS3-blaLAP-2 module in a synanthropic pigeon, Brazil.

OBJECTIVES: The aim of this study was to perform a genomic investigation of a multiple fluoroquinolone-resistant Leclercia adecarboxylata strain isolated from a synanthropic pigeon in São Paulo, Brazil. METHODS: Whole-genome sequencing was performed using an Illumina platform, and in silico deep analyses of the resistome were performed. Comparative phylogenomics was conducted using a global collection of publicly available genomes of L. adecarboxylata strains isolated from human and animal hosts. RESULTS: L. adecarboxylata strain P62P1 displayed resistance to human (norfloxacin, ofloxacin, ciprofloxacin, and levofloxacin) and veterinary (enrofloxacin) fluoroquinolones. This multiple quinolone-resistant profile was associated with mutations in the gyrA (S83I) and parC (S80I) genes and the presence of the qnrS gene within an ISKpn19-orf-qnrS1-ΔIS3-blaLAP-2 module, previously identified in L. adecarboxylata strains isolated from pig feed and faeces in China. Genes associated with arsenic, silver, copper, and mercury resistance were also predicted. Phylogenomic analysis revealed clustering (378-496 single nucleotide polymorphism differences) with two L. adecarboxylata strains isolated from human and fish sources in China and Portugal, respectively. CONCLUSIONS: L. adecarboxylata is a Gram-negative bacterium of the Enterobacterales order and is considered an emergent opportunistic pathogen. Since L. adecarboxylata has adapted to human and animal hosts, genomic surveillance is highly recommended, in order to identify the emergence and spread of resistant lineages and high-risk clones. In this regard, this study provides genomic data that can help clarify the role of synanthropic animals in the dissemination of clinically relevant L. adecarboxylata within a One Health context.

One health clones of multidrug-resistant Escherichia coli carried by synanthropic animals in Brazil.

WHO priority pathogens have disseminated beyond hospital settings and are now being detected in urban and wild animals worldwide. In this regard, synanthropic animals such as urban pigeons (Columba livia) and rodents (Rattus rattus, Rattus norvegicus and Mus musculus) are of interest to public health due to their role as reservoirs of pathogens that can cause severe diseases. These animals usually live in highly contaminated environments and have frequent interactions with humans, domestic animals, and food chain, becoming sentinels of anthropogenic activities. In this study, we report genomic data of Escherichia coli strains selected for ceftriaxone and ciprofloxacin resistance, isolated from pigeons and black rats. Genomic analysis revealed the occurrence of international clones belonging to ST10, ST155, ST224 and ST457, carrying a broad resistome to beta-lactams, aminoglycosides, trimethoprim/sulfamethoxazole, fluoroquinolones, tetracyclines and/or phenicols. SNP-based phylogenomic investigation confirmed clonal relatedness with high-risk lineages circulating at the human-animal-environmental interface globally. Our results confirm the dissemination of WHO priority CTX-M-positive E. coli in urban rodents and pigeons in Brazil, highlighting potential of these animals as infection sources and hotspot for dissemination of clinically relevant pathogens and their resistance genes, which is a critical issue within a One Health perspective.

Rodenticide efficacy in sewers in São Paulo, Brazil.

Rodents infest urban environments, causing damage and acting as vectors for disease transmission. Currently, anticoagulants are the most widely used chemical rodenticides, and their extensive and widespread use can contaminate the environment. To ensure effectiveness and avoid accumulation of rodent baits in the environment, it is important to evaluate how long rodent baits maintain their palatability and efficacy. In rodent control programs, rodent baits are placed in locations such as sewers, but after a few days, baits appear altered, causing doubts about the control efficacy. For this reason, baits are replaced periodically, which increases costs and generation of chemical waste. The objective of this study was to evaluate the palatability and efficacy of commercial paraffin-type rodent bait blocks placed in sewers in São Paulo City over a period of 90 days. Bait blocks were placed in sewers and collected after 30, 60, and 90 days. Additionally, in a laboratory two-choice test, wild-caught urban Norway rats were offered 40-60 g of bait and an equal volume of standard rat pellets. The amount of bait and rat pellet consumed was registered, the palatability was calculated, and the efficacy was measured as the percentage mortality over 14 days. The results showed that, even when they had an altered appearance, bait blocks remained palatable to the rats and were effective after at least 90 days. Leaving bait blocks for longer periods could be an effective strategy for reducing costs and could help to ensure the control of urban rodents in an environmentally sustainable way.

Decrease in mortality rate and hospital admissions for acute myocardial infarction after the enactment of the smoking ban law in São Paulo city, Brazil.

BACKGROUND: Smoking restriction laws have spread worldwide during the last decade. Previous studies have shown a decline in the community rates of myocardial infarction after enactment of these laws. However, data are scarce about the Latin American population. In the first phase of this study, we reported the successful implementation of the law in São Paulo city, with a decrease in carbon monoxide rates in hospitality venues. OBJECTIVE: To evaluate whether the 2009 implementation of a comprehensive smoking ban law in São Paulo city was associated with a reduction in rates of mortality and hospital admissions for myocardial infarction. METHODS: We performed a time-series study of monthly rates of mortality and hospital admissions for acute myocardial infarction from January 2005 to December 2010. The data were derived from DATASUS, the primary public health information system available in Brazil and from Mortality Information System (SIM). Adjustments and analyses were performed using the Autoregressive Integrated Moving Average with exogenous variables (ARIMAX) method modelled by environmental variables and atmospheric pollutants to evaluate the effect of smoking ban law in mortality and hospital admission rate. We also used Interrupted Time Series Analysis (ITSA) to make a comparison between the period pre and post smoking ban law. RESULTS: We observed a reduction in mortality rate (-11.9% in the first 17 months after the law) and in hospital admission rate (-5.4% in the first 3 months after the law) for myocardial infarction after the implementation of the smoking ban law. CONCLUSIONS: Hospital admissions and mortality rate for myocardial infarction were reduced in the first months after the comprehensive smoking ban law was implemented.

Palatability and efficacy of bromadiolone rodenticide block bait previously exposed to environmental conditions.

BACKGROUND: In São Paulo city, rodent infestation is considered to be a serious public health problem and is the object of a municipal rodent control programme. One of the most important routine methods involves baiting in sewers, using bromadiolone block bait in a pulsed baiting strategy. It has been observed that, after each pulse, bait is not always consumed, and its appearance is altered, which has led to concerns about efficacy. We assessed whether exposure to sewer conditions influences the palatability and efficacy of rodenticide baits to Norway rats (Rattus norvegicus). Baits containing bromadiolone as active ingredient were placed in sewers, removed after 30 days and offered to rats in a two-choice food trial and a no-choice food trial. RESULTS: The appearance of the rodenticide baits changed after 30 days exposure to sewer conditions, but they continued to be palatable and effective against rats. The level of mortality was considered to be satisfactory, 75% in the two-choice food trial and 100% in the no-choice food trial. CONCLUSION: Results support the reuse of rodenticide block bait in rodent control. It seems to be justified to continue using/reuse baits even when their appearance has changed after 30 days exposure in sewer systems.

Environmental conditions and rodent infestation in Campo Limpo district, Sao Paulo municipality, Brazil.

Rodents are involved in the transmission to human beings of several diseases, including liptospirosis, which shows high lethality rates in Sao Paulo municipality. Despite this, few studies have assessed the relationship existing between urban environmental conditions and building rodent infestation. With the purpose of clarifying this relationship, an analysis has been conducted in order to quantify the influence of environmental factors upon rodent infestation on a low-income district. Diagnosis of the environmental situation has been performed to evaluate the frequency according to which harborage, food and access sources occur, and a survey on infestation rates in 2175 dwellings in the area studied. The logistic regression analysis showed that among the environmental variables, the one that showed the closest association with rodent infestation was access; followed by harborage, and food. It was concluded that poor socioeconomic and environmental conditions in the area propitiate the occurrence of high rodent infestation rates.

Evaluation on the effectiveness of actions for controlling infestation by rodents in Campo Limpo region, Sao Paulo Municipality, Brazil.

Rodents are responsible for the transmission of more than 60 diseases both to human beings and to domestic animals. The increase in rodent infestation in a given area brings several health problems to the nearby population. Thus, when infestation increases, it is time to take intervention measures. Although many countries have implemented programs aimed at controlling rodent infestation, literature on studies evaluating the effectiveness of intervention measures in urban areas is scarce. Aimed at contributing to the understanding of rodents' population dynamics in urban areas, the objective of this study was to evaluate the effectiveness of the control methods proposed by "Programa de Vigilancia e Controle de Roedores do Municipio de Sao Paulo" (Program for Rodents Surveillance and Control in Sao Paulo Municipality), conducted on Jardim Comercial District. As a first step, a survey to assess infestation rates was conducted in 1529 dwellings located in the area studied. After that, a chemical control upon rodents was accomplished in every dwelling infested. One week and six months after completion of control measures, a new evaluation on infestation rates was carried out, in order to verify the effectiveness of the procedures taken and to estimate the re-infestation capacity. Initial infestation rate was 40.0%, and the final infestation rate, 14.4%. Therefore, the effectiveness of the control methods utilized was 63.8%. It can thus be concluded that the control methods applied were quite effective.