Point Prevalence Survey of Antimicrobial Use in Four Tertiary Care Hospitals in Mexico

PURPOSE

To describe the antimicrobial use in four tertiary care hospitals in Mexico.

PATIENTS AND METHODS

Point prevalence surveys (PPSs) were conducted on medical records of hospitalized patients with prescribed antimicrobials (AMs) in four tertiary care hospitals in Mexico in 2019. Prevalence estimates and descriptive statistics were used to present the collected data on antimicrobial prescribing and microbiological studies.

RESULTS

The prevalence of patients with prescribed AMs among the hospitals ranged from 47.1% to 91.3%. Antibiotics for systemic use (J01s) were the most prescribed (84.6%, [95% CI: 81.5-87.3]), mainly extended-spectrum J01s: third-generation cephalosporins 19.8% [95% CI: 16.8-23.1], and carbapenems 17.0% [95% CI: 14.2-20.2]. Antibiotic treatments were largely empirical, with no planned duration or review dates. The ceftriaxone use was excessive and prolonged. No formal reference guidelines for antimicrobial prescribing were available in the hospitals. Multidrug-resistant Escherichia coli and ESKAPE pathogens were identified in all hospitals.

CONCLUSION

This study describes the extensive use of antimicrobials and broad-spectrum antibiotics for systemic use in Mexican hospitals, along with the presence of resistant pathogens to the antibiotics frequently used in the hospitals surveyed.

Prediction of neuropeptide precursors and differential expression of adipokinetic hormone/corazonin-related peptide, hugin and corazonin in the brain of malaria vector Nyssorhynchus albimanus during a Plasmodium berghei infection

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We describe precursors that predicted at least sixty neuropeptides in Ny. albimanus.

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At least 16 precursors are encoded in the Ny. albimanus brain.

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Myosuppressin neuropeptide precursor was identified in Ny albimanus.

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acp and hugin transcripts increased in Ny. albimanus brains infected with P. berghei.

Insect neuropeptides, play a central role in the control of many physiological processes. Based on an analysis of Nyssorhynchus albimanus brain transcriptome a neuropeptide precursor database of the mosquito was described. Also, we observed that adipokinetic hormone/corazonin-related peptide (ACP), hugin and corazonin encoding genes were differentially expressed during Plasmodium infection. Transcriptomic data from Ny. albimanus brain identified 29 pre-propeptides deduced from the sequences that allowed the prediction of at least 60 neuropeptides. The predicted peptides include isoforms of allatostatin C, orcokinin, corazonin, adipokinetic hormone (AKH), SIFamide, capa, hugin, pigment-dispersing factor, adipokinetic hormone/corazonin-related peptide (ACP), tachykinin-related peptide, trissin, neuropeptide F, diuretic hormone 31, bursicon, crustacean cardioactive peptide (CCAP), allatotropin, allatostatin A, ecdysis triggering hormone (ETH), diuretic hormone 44 (Dh44), insulin-like peptides (ILPs) and eclosion hormone (EH). The analysis of the genome of An. albimanus and the generated transcriptome, provided evidence for the identification of myosuppressin neuropeptide precursor. A quantitative analysis documented increased expression of precursors encoding ACP peptide, hugin and corazonin in the mosquito brain after Plasmodium berghei infection. This work represents an initial effort to characterize the neuropeptide precursors repertoire of Ny. albimanus and provides information for understanding neuroregulation of the mosquito response during Plasmodium infection.

Adaptations in energy metabolism and gene family expansions revealed by comparative transcriptomics of three Chagas disease triatomine vectors

Background

Chagas disease is a parasitic infection caused by Trypanosoma cruzi. It is an important public health problem affecting around seven to eight million people in the Americas. A large number of hematophagous triatomine insect species, occupying diverse natural and human-modified ecological niches transmit this disease. Triatomines are long-living hemipterans that have evolved to explode different habitats to associate with their vertebrate hosts. Understanding the molecular basis of the extreme physiological conditions including starvation tolerance and longevity could provide insights for developing novel control strategies. We describe the normalized cDNA, full body transcriptome analysis of three main vectors in North, Central and South America, Triatoma pallidipennis, T. dimidiata and T. infestans.

Results

Two-thirds of the de novo assembled transcriptomes map to the Rhodnius prolixus genome and proteome. A Triatoma expansion of the calycin family and two types of protease inhibitors, pacifastins and cystatins were identified. A high number of transcriptionally active class I transposable elements was documented in T. infestans, compared with T. dimidiata and T. pallidipennis. Sequence identity in Triatoma-R. prolixus 1:1 orthologs revealed high sequence divergence in four enzymes participating in gluconeogenesis, glycogen synthesis and the pentose phosphate pathway, indicating high evolutionary rates of these genes. Also, molecular evidence suggesting positive selection was found for several genes of the oxidative phosphorylation I, III and V complexes.

Conclusions

Protease inhibitors and calycin-coding gene expansions provide insights into rapidly evolving processes of protease regulation and haematophagy. Higher evolutionary rates in enzymes that exert metabolic flux control towards anabolism and evidence for positive selection in oxidative phosphorylation complexes might represent genetic adaptations, possibly related to prolonged starvation, oxidative stress tolerance, longevity, and hematophagy and flight reduction. Overall, this work generated novel hypothesis related to biological adaptations to extreme physiological conditions and diverse ecological niches that sustain Chagas disease transmission.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4696-8) contains supplementary material, which is available to authorized users.

North American import? Charting the origins of an enigmatic Trypanosoma cruzi domestic genotype

BACKGROUND

Trypanosoma cruzi, the agent of Chagas disease, is currently recognized as a complex of six lineages or Discrete Typing Units (DTU): TcI-TcVI. Recent studies have identified a divergent group within TcI - TcI(DOM). TcI(DOM). is associated with a significant proportion of human TcI infections in South America, largely absent from local wild mammals and vectors, yet closely related to sylvatic strains in North/Central America. Our aim was to examine hypotheses describing the origin of the TcI(DOM) genotype. We propose two possible scenarios: an emergence of TcI(DOM) in northern South America as a sister group of North American strain progenitors and dispersal among domestic transmission cycles, or an origin in North America, prior to dispersal back into South American domestic cycles. To provide further insight we undertook high resolution nuclear and mitochondrial genotyping of multiple Central American strains (from areas of México and Guatemala) and included them in an analysis with other published data.

FINDINGS

Mitochondrial sequence and nuclear microsatellite data revealed a cline in genetic diversity across isolates grouped into three populations: South America, North/Central America and TcI(DOM). As such, greatest diversity was observed in South America (A(r) = 4.851, π = 0.00712) and lowest in TcI(DOM) (Ar = 1.813, π = 0.00071). Nuclear genetic clustering (genetic distance based) analyses suggest that TcI(DOM) is nested within the North/Central American clade.

CONCLUSIONS

Declining genetic diversity across the populations, and corresponding hierarchical clustering suggest that emergence of this important human genotype most likely occurred in North/Central America before moving southwards. These data are consistent with early patterns of human dispersal into South America.

Biological and genetic aspects of crosses between phylogenetically close species of Mexican triatomines (Hemiptera: Reduviidae)

Reproductive isolation between Triatoma mexicana (Herrich-Scaeffer) and the six species of the Phyllosoma complex, belonging to the genus Meccus, was examined by analyzing the fertility of experimental hybrids. The percentage of couples with offspring was highest in the set of crosses between Meccus phyllosomus (Burmeister) and T. mexicana, and lowest in those between Meccus pallidipennis (Stål) and Meccus bassolsae (Alejandre-Aguilar, Nogueda-Torres, Cortés-Jiménez, Jurberg, Galvão, and Carcavallo) with respect to T. mexicana. Crosses between Meccus mazzottii (Usinger), Meccus picturatus (Usinger), and Meccus longipennis (Usinger) and T. mexicana had scarce offspring, whereas offspring from crosses between M. phyllosomus and T. mexicana were abundant. However, all F1 nymphs died in different instars before reaching sexual maturity. The biological evidence in this study suggests that different degrees of reproductive isolation exist between T mexicana and the different species of Meccus. Our data also support the current status of T. mexicana as a separate species.