Spatiotemporal distribution and sociodemographic and socioeconomic factors associated with primary and secondary syphilis in Guangdong,China, 2005–2017

BackgroundPrevious studies exploring the factors associated with the incidence of syphilis have mostly focused on individual-level factors. However, recent evidence has indicated that social-level factors, such as sociodemographic and socioeconomic factors, also affect the incidence of syphilis. Studies on the sociodemographic and socioeconomic factors associated with syphilis incidence are scarce, and they have rarely controlled for spatial effects, even though syphilis shows spatial autocorrelation.Methodology/Principal findingsSyphilis data from 21 cities in Guangdong province between 2005 and 2017 were provided by the National Notifiable Infectious Disease Reporting Information System. The incidence time series, incidence map, and space-time scanning data were used to visualize the spatiotemporal distribution. The spatial panel data model was then applied to explore the relationship between sociodemographic factors (population density, net migration rate, male:female ratio, and the number of health institutions per 1,000 residents), socioeconomic factors (gross domestic product per capita, the proportion of secondary/tertiary industry), and the incidence of primary and secondary syphilis after controlling for spatial effects. The incidence of syphilis increased slowly from 2005 (11.91 per 100,000) to 2011 (13.42 per 100,000) and then began to decrease, reaching 6.55 per 100,000 in 2017. High-risk clusters of syphilis tended to shift from developed areas to underdeveloped areas. An inverted U-shaped relationship was found between syphilis incidence and gross domestic product per capita. Moreover, syphilis incidence was significantly associated with population density (β = 2.844, P = 0.006), the number of health institutions per 1,000 residents (β = -0.095, P = 0.007), and the net migration rate (β = -0.219, P = 0.002).Conclusions/SignificanceOur findings suggest that the incidence of primary and secondary syphilis first increase before decreasing as economic development increases further. These results emphasize the necessity to prevent syphilis in regions at the early stages of economic growth.     

Frequency of fatal congenital anomalies of the nervous system: Association with geographic latitude

Abstract

We report a significant pole‐to‐equator gradient in fatal congenital defects of the central nervous system whose rates increase directly with increasing latitudes in either hemisphere of the American continent. This gradient was not observed in deaths due to malformations of other organ systems and is in the opposite direction to the well‐recognized one between latitude and childhood mortality.     

Structure of the Bacterial Deacetylase LpxC Bound to the Nucleotide Reaction Product Reveals Mechanisms of Oxyanion Stabilization and Proton Transfer

The emergence of antibiotic-resistant strains of pathogenic bacteria is an increasing threat to global health that underscores an urgent need for an expanded antibacterial armamentarium. Gram-negative bacteria, such as Escherichia coli, have become increasingly important clinical pathogens with limited treatment options. This is due in part to their lipopolysaccharide (LPS) outer membrane components, which dually serve as endotoxins while also protecting Gram-negative bacteria from antibiotic entry. The LpxC enzyme catalyzes the committed step of LPS biosynthesis, making LpxC a promising target for new antibacterials. Here, we present the first structure of an LpxC enzyme in complex with the deacetylation reaction product, UDP-(3-O-(R-3-hydroxymyristoyl))-glucosamine. These studies provide valuable insight into recognition of substrates and products by LpxC and a platform for structure-guided drug discovery of broad spectrum Gram-negative antibiotics.     

An Estimation of Private Household Costs to Receive Free Oral Cholera Vaccine in Odisha,India

BackgroundService provider costs for vaccine delivery have been well documented; however, vaccine recipients’ costs have drawn less attention. This research explores the private household out-of-pocket and opportunity costs incurred to receive free oral cholera vaccine during a mass vaccination campaign in rural Odisha, India.MethodsFollowing a government-driven oral cholera mass vaccination campaign targeting population over one year of age, a questionnaire-based cross-sectional survey was conducted to estimate private household costs among vaccine recipients. The questionnaire captured travel costs as well as time and wage loss for self and accompanying persons. The productivity loss was estimated using three methods: self-reported, government defined minimum daily wages and gross domestic product per capita in Odisha.FindingsOn average, families were located 282.7 (SD = 254.5) meters from the nearest vaccination booths. Most family members either walked or bicycled to the vaccination sites and spent on average 26.5 minutes on travel and 15.7 minutes on waiting. Depending upon the methodology, the estimated productivity loss due to potential foregone income ranged from $0.15 to $0.29 per dose of cholera vaccine received. The private household cost of receiving oral cholera vaccine constituted 24.6% to 38.0% of overall vaccine delivery costs.InterpretationThe private household costs resulting from productivity loss for receiving a free oral cholera vaccine is a substantial proportion of overall vaccine delivery cost and may influence vaccine uptake. Policy makers and program managers need to recognize the importance of private costs and consider how to balance programmatic delivery costs with private household costs to receive vaccines.     

Increasingly expanded future risk of dengue fever in the Pearl River Delta,China

BackgroundIn recent years, frequent outbreaks of dengue fever (DF) have become an increasingly serious public health issue in China, especially in the Pearl River Delta (PRD) with fast socioeconomic developments. Previous studies mainly focused on the historic DF epidemics, their influencing factors, and the prediction of DF risks. However, the future risks of this disease under both different socioeconomic development and representative concentration pathways (RCPs) scenarios remain little understood.Methodology and principal findingsIn this study, a spatial dataset of gross domestic product (GDP), population density, and land use and land coverage (LULC) in 2050 and 2070 was obtained by simulation based on the different shared socioeconomic pathways (SSPs), and the future climatic data derived from the RCP scenarios were integrated into the Maxent models for predicting the future DF risk in the PRD region. Among all the variables included in this study, socioeconomics factors made the dominant contribution (83% or so) during simulating the current spatial distribution of the DF epidemics in the PRD region. Moreover, the spatial distribution of future DF risk identified by the climatic and socioeconomic (C&S) variables models was more detailed than that of the climatic variables models. Along with global warming and socioeconomic development, the zones with DF high and moderate risk will continue to increase, and the population at high and moderate risk will reach a maximum of 48.47 million (i.e., 63.78% of the whole PRD) under the RCP 4.5/SSP2 in 2070.ConclusionsThe increasing DF risk may be an inevitable public health threat in the PRD region with rapid socioeconomic developments and global warming in the future. Our results suggest that curbs in emissions and more sustainable socioeconomic growth targets offer hope for limiting the future impact of dengue, and effective prevention and control need to continue to be strengthened at the junction of Guangzhou-Foshan, north-central Zhongshan city, and central-western Dongguan city. Our study provides useful clues for relevant hygienic authorities making targeted adapting strategies for this disease.     

Incidence of adult brain cancers is higher in countries where the protozoan parasite Toxoplasma gondii is common

We explored associations between the common protozoan parasite Toxoplasma gondii and brain cancers in human populations. We predicted that T. gondii could increase the risk of brain cancer because it is a long-lived parasite that encysts in the brain, where it provokes inflammation and inhibits apoptosis. We used a medical geography approach based on the national incidence of brain cancers and seroprevalence of T. gondii. We corrected reports of incidence for national gross domestic product because wealth probably increases the ability to detect cancer. We also included gender, cell phone use and latitude as variables in our initial models. Prevalence of T. gondii explained 19 per cent of the residual variance in brain cancer incidence after controlling for the positive effects of gross domestic product and latitude among nations. Infection with T. gondii was associated with a 1.8-fold increase in the risk of brain cancers across the range of T. gondii prevalence in our dataset (4-67%). These results, though correlational, suggest that T. gondii should be investigated further as a possible oncogenic pathogen of humans.     

Characterization of Substances that Restore Impaired Cell Division of UV-Irradiated E. coli B

Substances which restore impaired cell division in UV-irradiated E. coli B were surveyed among various bacteria. The active substance was found only in several genera of Gram-negative bacteria, i.e., Escherichia, Enterobacter, Salmonella and some species of Pseudomonas. The activity in the dialyzed cell extract of E. coli B/r was observed in the presence of β-NAD and was enhanced by Mg^{2 +} and Mn²⁺. The active substance was very labile, but the activity was protected by 1 mM dithiothreitol in the process of purification. The activity of a fraction recovered through DEAE-cellulose column chromatography was stimulated by the presence of membrane fraction. Upon treatment with lipid-degrading enzymes and proteases, the division-stimulating activity was lost or reduced. It appears that the inactivation by lipase and phospholipase A₂ was due to the formation of lysophospholipids and that a proteinous substance participated in the recovery of impaired cell division of UV-irradiated E. coli B.     

Cost Attributable to Nosocomial Bacteremia. Analysis According to Microorganism and Antimicrobial Sensitivity in a University Hospital in Barcelona

AimTo calculate the incremental cost of nosocomial bacteremia caused by the most common organisms, classified by their antimicrobial susceptibility.MethodsWe selected patients who developed nosocomial bacteremia caused by Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, or Pseudomonas aeruginosa. These microorganisms were analyzed because of their high prevalence and they frequently present multidrug resistance. A control group consisted of patients classified within the same all-patient refined-diagnosis related group without bacteremia. Our hospital has an established cost accounting system (full-costing) that uses activity-based criteria to analyze cost distribution. A logistic regression model was fitted to estimate the probability of developing bacteremia for each admission (propensity score) and was used for propensity score matching adjustment. Subsequently, the propensity score was included in an econometric model to adjust the incremental cost of patients who developed bacteremia, as well as differences in this cost, depending on whether the microorganism was multidrug-resistant or multidrug-sensitive.ResultsA total of 571 admissions with bacteremia matched the inclusion criteria and 82,022 were included in the control group. The mean cost was € 25,891 for admissions with bacteremia and € 6,750 for those without bacteremia. The mean incremental cost was estimated at € 15,151 (CI, € 11,570 to € 18,733). Multidrug-resistant P. aeruginosa bacteremia had the highest mean incremental cost, € 44,709 (CI, € 34,559 to € 54,859). Antimicrobial-susceptible E. coli nosocomial bacteremia had the lowest mean incremental cost, € 10,481 (CI, € 8,752 to € 12,210). Despite their lower cost, episodes of antimicrobial-susceptible E. coli nosocomial bacteremia had a major impact due to their high frequency.ConclusionsAdjustment of hospital cost according to the organism causing bacteremia and antibiotic sensitivity could improve prevention strategies and allow their prioritization according to their overall impact and costs. Infection reduction is a strategy to reduce resistance.     

Seeds tend to disperse further in the tropics

Despite the importance of seed dispersal in a plant's life cycle, global patterns in seed dispersal distance have seldom been studied. This paper presents the first geographically and taxonomically broad quantification of the latitudinal gradient in seed dispersal distance. Although there is substantial variation in the seed dispersal distances of different species at a given latitude, seeds disperse on average more than an order of magnitude further at the equator than towards the poles. This pattern is partially explained by plant life‐history traits that simultaneously associate with seed dispersal distance and latitude, including dispersal mode and plant height. The extended seed shadow of tropical plants could increase the distance between conspecific individuals. This could facilitate species coexistence and contribute to the maintenance of high plant diversity in tropical communities. The latitudinal gradient in dispersal distance also has implications for species’ persistence in the face of habitat fragmentation and climate change.     

Geographic Variation in Maternal Smoking during Pregnancy in the Missouri Adolescent Female Twin Study (MOAFTS)

ObjectiveDespite well-known adverse health effects of maternal smoking during pregnancy (MSP), it is still unclear if MSP varies geographically and if neighborhood socioeconomic deprivation (SED) plays an important role in MSP. This study aims to investigate small-area geographic variation in MSP and examine the association of SED with MSP.MethodsThe Missouri Adolescent Female Twin Study (MOAFTS) is a cohort study of female like-sex twins born in Missouri to Missouri-resident parents during 1975–1985. Biological mothers completed a baseline interview in 1995–1998 and reported MSP with the twins. Residential address of the mother at birth was geocoded. We developed a census tract-level SED index using a common factor approach based on 21 area-level socioeconomic variables from the 1980 Census data. Multilevel logistic regressions estimated geographic heterogeneity (random effect) in MSP and the odds ratios (ORs, fixed effects) of neighborhood SED associated with MSP.ResultsOf 1658 MOAFTS mothers, 35.2% reported any MSP and 21.9% reported MSP beyond the first trimester. Neighborhood SED was associated with any MSP (the highest vs. the lowest quartile: OR = 1.90, 95% confidence interval [CI] = 1.40–2.57, P_trend<0.001) and MSP beyond the first trimester (OR = 1.98, 95% CI = 1.38–2.85, P_trend = 0.002) in unadjusted analyses. After adjusting for individual covariates (demographics, socioeconomic conditions, alcohol use, and parents’ cohabitation), neighborhood SED was not associated with MSP, but geographic variation still persisted in MSP (variance = 0.41, P = 0.003) and in MSP beyond the first trimester (variance = 0.82, P<0.001).ConclusionsNeighborhood SED was associated with MSP in unadjusted analyses but this association could be explained by individual socioeconomic conditions. Nonetheless, significant geographic variation in MSP persisted and was not accounted for by differences in neighborhood SED. To develop effective interventions to reduce MSP, further studies are necessary to explore underlying reasons for its geographic variation.     

Structural and mechanistic insights into EchAMP: A antimicrobial protein from the Echidna milk

BackgroundAntibiotic resistance is a problem that necessitates the identification of new antimicrobial molecules. Milk is known to have molecules with antimicrobial properties (AMPs). Echidna Antimicrobial Protein (EchAMP) is one such lactation specific AMP exclusively found in the milk of Echidna, an egg-laying mammal geographically restricted to Australia and New Guinea. Previous studies established that EchAMP exhibits substantial bacteriostatic activity against multiple bacterial genera. However, the subsequent structural and functional studies were hindered due to the unavailability of pure protein.ResultsIn this study, we expressed EchAMP protein using a heterologous expression system and successfully purified it to >95% homogeneity. The purified recombinant protein exhibits bacteriolytic activity against both Gram-positive and Gram-negative bacteria as confirmed by live-dead staining and scanning electron microscopy. Structurally, this AMP belongs to the family of intrinsically disordered proteins (IDPs) as deciphered by the circular-dichroism, tryptophan fluorescence, and NMR spectroscopy. Nonetheless, EchAMP has the propensity to acquire structure with amphipathic molecules, or membrane mimics like SDS, lipopolysaccharides, and liposomes as again observed through multiple spectroscopic techniques.ConclusionsRecombinant EchAMP exhibits broad-spectrum bacteriolytic activity by compromising the bacterial cell membrane integrity. Hence, we propose that this intrinsically disordered antimicrobial protein interact with the bacterial cell membrane and undergoes conformational changes to form channels in the membrane resulting in cell lysis.General significanceEchAMP, the evolutionarily conserved, lactation specific AMP from an oviparous mammal may find application as a broad-spectrum antimicrobial against pathogens that affect mammary gland or otherwise cause routine infections in humans and livestock.     

Life‐history traits related to diapause in univoltine and bivoltine populations of Ypthima multistriata (Lepidoptera: Satyridae) inhabiting similar latitudes

In most temperate insects, diapause strategies and voltinism generally exhibit latitudinal clines, supporting the concept that they represent adaptations to climate. In contrast, in the satyrine butterfly Ypthima multistriata Butler, local populations with different voltinism patterns are geographically intermingled, suggesting that life‐history traits related to diapause may differ even between geographically and phylogenetically close populations. In this study, we experimentally examined the critical photoperiod for diapause induction and the larval developmental period in two univoltine and two bivoltine populations of Y. multistriata, all of which inhabit virtually the same latitude (34.652–34.750°N). We found that the critical photoperiod for diapause induction was longer in the univoltine populations than in the bivoltine populations. Moreover, the larval period under the long day length treatment was different among populations in both sexes, although significant differences were also detected between populations with the same voltinism. These results indicate that in Y. multistriata, life‐history traits related to diapause can not be attributed merely to climatic conditions such as temperature or day length, which depend largely on latitude. Therefore, we suggest that biotic elements, such as leaf toughness, as well as abiotic elements should be taken into account in attempts to explain the enigmatic pattern of geographic variation in the diapause strategies of Y. multistriata.     

Analysis of microbiota in cultures of the green microalga Tetraselmis suecica

ABSTRACT

Bacteria associated with microalgae strongly affect algal biomass and derived product yield and quality. Nevertheless, only a few studies have addressed the detailed phylogenetic characterization of bacterial communities associated with microalgae. In this study, the phycospheric bacterial communities associated with different Tetraselmis suecica F&M-M33 cultures, a green marine microalga with several industrial applications, were analysed using a metagenomic approach. The T. suecica F&M-M33 cultures used originated from the same ancestral microalgal non-axenic culture but were physically and geographically separated for years and maintained under different growing conditions. Despite the different history of the cultures, a ‘core’ bacterial community was identified, accounting for 70% of the total bacterial community and formed by at least 13 families. Among the ‘core’ operational taxonomic units (OTUs), 24 different genera were identified. Nevertheless, there was a high variability in the relative proportions of the taxa forming the ‘core’ community, indicating that the growing conditions and/or external contamination influence the relative abundance of these microorganisms. Our study allowed the identification of persistent taxa that may be used to deepen the knowledge of the complex relationship between T. suecica and its associated bacteria.     

Comparative evaluation of seminal,vaginal, and rectal bacterial flora in the cheetah and domestic cat

To determine the status and potential impact of microorganisms on reproductive health, bacterial cultures were evaluated from cheetah seminal, vaginal, and rectal swabs and the results compared to those from clinically healthy, domestic cats. Aerobic bacteria were isolated in the semen from 26 of the 40 (65.0%) cheetahs and 25 of the 27 (92.6%) domestic cats. Gram-negative organisms predominated in the electroejaculates of both species, accounting for >70% of the total bacterial isolates. The most common seminal organism in both species was hemolytic Escherichia coli. Bacteria were isolated from vaginal samples obtained from 49 of the 67 (73.1%) cheetahs and 46 of the 49 (93.9%) domestic cats. Gram-negative organisms dominated, representing >63% of the vaginal bacteria, and again hemolytic E. coli was the most prevalent isolate in both species. None of the cheetah or domestic cat vaginal cultures contained Mycoplasma spp. or Ureaplasma spp. Numerous gram-negative and gram-positive bacteria were identified in rectal cultures of 73 cheetahs and 60 domestic cats, but hemolytic E. coli clearly was the most common isolate. Within each species, a comparison between electroejaculates that were positive vs. negative for hemolytic E. coli growth revealed no differences in sperm concentration, sperm motility ratings, or the proportion of structurally abnormal spermatozoa. Neutrophils were not detected in any of the 67 felid ejaculates, and the presence of seminal hemolytic E. coli was unrelated to fertility, on the basis of past ability to sire young or fertilize oocytes in vitro. Vaginal cytologic evaluations in both the cheetah and domestic cat indicated that hemolytic E. coli was not associated with a pathologic inflammatory response. Overall fecundity and proven ability to produce young were similar between females producing positive or negative vaginal cultures for E. coli. These findings indicate that commensal bacteria exist in the reproductive tract of the cheetah and domestic cat, and these organisms constitute normal, apparently innocuous bacterial microflora in the semen and vagina. © 1993 Wiley-Liss, Inc.     

TRIF Licenses Caspase-11-Dependent NLRP3 Inflammasome Activation by Gram-Negative Bacteria

Systemic infections with Gram-negative bacteria are?characterized by high mortality rates due to the "sepsis syndrome," a widespread and uncontrolled inflammatory response. Though it is well recognized that the immune response during Gram-negative bacterial infection is initiated after the recognition of endotoxin by Toll-like receptor 4, the molecular mechanisms underlying the detrimental inflammatory response during Gram-negative bacteremia remain poorly defined. Here, we identify a TRIF pathway that licenses NLRP3 inflammasome activation by all Gram-negative bacteria. By engaging TRIF, Gram-negative bacteria activate caspase-11. TRIF activates caspase-11 via type I IFN signaling, an event that is both necessary and sufficient for caspase-11 induction and autoactivation. Caspase-11 subsequently synergizes with the assembled NLRP3 inflammasome to regulate caspase-1 activation and leads to caspase-1-independent cell death. These events occur specifically during infection with Gram-negative, but not Gram-positive, bacteria. The identification of TRIF as a regulator of caspase-11 underscores the importance of TLRs as master regulators of inflammasomes during Gram-negative bacterial infection.     

Biomethanation of Spent Wash: Bacterial Pretreatment to Remove Heavy Metals by Adsorption

In a semicontinuous fermentation system, biomethanation of diluted spent wash (DW, initial COD 25–27 g/l) resulted in only 0.2 l/l of methane production in 20 d. Two capsular Gram-negative strains of bacteria were used for adsorption of heavy metals such as lead, copper, and zinc from spent wash. Strain I removed 64 % of the lead in 1 h and 82% of the copper in 2 h, while strain II removed 76% of the zinc in 2 h. The diluted spent wash from which heavy metals were removed was supplemented with synthetic medium and an acidophilic strain of Candida sp. This treatment improved methanogenesis. In 12 d, 4.9 l/l of biogas containing 63% methane was produced.     

Metabolic Response to Klebsiella pneumoniae Infection in an Experimental Rat Model

Bacteremia, the presence of viable bacteria in the blood stream, is often associated with several clinical conditions. Bacteremia can lead to multiple organ failure if managed incorrectly, which makes providing suitable nutritional support vital for reducing bacteremia-associated mortality. In order to provide such information, we investigated the metabolic consequences of a Klebsiella pneumoniae (K. pneumoniae) infection in vivo by employing a combination of ¹H nuclear magnetic resonance spectroscopy and multivariate data analysis. K. pneumoniae was intravenously infused in rats; urine and plasma samples were collected at different time intervals. We found that K. pneumoniae-induced bacteremia stimulated glycolysis and the tricarboxylic acid cycle and also promoted oxidation of fatty acids and creatine phosphate to facilitate the energy-demanding host response. In addition, K. pneumoniae bacteremia also induced anti-endotoxin, anti-inflammatory and anti-oxidization responses in the host. Furthermore, bacteremia could cause a disturbance in the gut microbiotal functions as suggested by alterations in a range of amines and bacteria-host co-metabolites. Our results suggest that supplementation with glucose and a high-fat and choline-rich diet could ameliorate the burdens associated with bacteremia. Our research provides underlying pathological processes of bacteremia and a better understanding of the clinical and biochemical manifestations of bacteremia.     

Gram-negative neonatal sepsis in low- and lower-middle-income countries and WHO empirical antibiotic recommendations: A systematic review and meta-analysis

BackgroundNeonatal sepsis is a significant global health issue associated with marked regional disparities in mortality. Antimicrobial resistance (AMR) is a growing concern in Gram-negative organisms, which increasingly predominate in neonatal sepsis, and existing WHO empirical antibiotic recommendations may no longer be appropriate. Previous systematic reviews have been limited to specific low- and middle-income countries. We therefore completed a systematic review and meta-analysis of available data from all low- and lower-middle-income countries (LLMICs) since 2010, with a focus on regional differences in Gram-negative infections and AMR.Methods and findingsAll studies published from 1 January 2010 to 21 April 2021 about microbiologically confirmed bloodstream infections or meningitis in neonates and AMR in LLMICs were assessed for eligibility. Small case series, studies with a small number of Gram-negative isolates (<10), and studies with a majority of isolates prior to 2010 were excluded. Main outcomes were pooled proportions of Escherichia coli, Klebsiella, Enterobacter, Pseudomonas, Acinetobacter and AMR. We included 88 studies (4 cohort studies, 3 randomised controlled studies, and 81 cross-sectional studies) comprising 10,458 Gram-negative isolates from 19 LLMICs. No studies were identified outside of Africa and Asia. The estimated pooled proportion of neonatal sepsis caused by Gram-negative organisms was 60% (95% CI 55% to 65%). Klebsiella spp. was the most common, with a pooled proportion of 38% of Gram-negative sepsis (95% CI 33% to 43%). Regional differences were observed, with higher proportions of Acinetobacter spp. in Asia and Klebsiella spp. in Africa. Resistance to aminoglycosides and third-generation cephalosporins ranged from 42% to 69% and from 59% to 84%, respectively. Study limitations include significant heterogeneity among included studies, exclusion of upper-middle-income countries, and potential sampling bias, with the majority of studies from tertiary hospital settings, which may overestimate the burden caused by Gram-negative bacteria.ConclusionsGram-negative bacteria are an important cause of neonatal sepsis in LLMICs and are associated with significant rates of resistance to WHO-recommended first- and second-line empirical antibiotics. AMR surveillance should underpin region-specific empirical treatment recommendations. Meanwhile, a significant global commitment to accessible and effective antimicrobials for neonates is required.

Sophie Wen and co-workers report a meta-analysis on bacterial isolates and antimicrobial resistance in neonatal sepsis in low- and lower-middle-income countries.     

Latitudinal variation in herbivory: influences of climatic drivers,herbivore identity and natural enemies

Although a number of investigations have concluded that lower latitudes are associated with increases in herbivore abundance and plant damage, the generality of this pattern is still under debate. Multiple factors may explain the lack of consistency in latitude–herbivory relationships. For instance, latitudinal variation in herbivore pressure may be shaped entirely or not by climatic variables, or vary among herbivore guilds with differing life‐history traits. Additionally, the strength of top–down effects from natural enemies on herbivores might also vary geographically and influence latitude–herbivory patterns. We carried out a field study where we investigated the effects of latitude and climate on herbivory by a seed‐eating caterpillar and leaf chewers, as well as parasitism associated to the former across 30 populations of the perennial herb Ruellia nudiflora (Acanthaceae). These populations were distributed along a 5° latitudinal gradient from northern Yucatan (Mexico) to southern Belize, representing one‐third of the species' latitudinal distribution and the entirety and one‐third of the precipitation and temperature gradient of this species' distribution (respectively). We found opposing latitudinal gradients of seed herbivory and leaf herbivory, and this difference appeared to be mediated by contrasting effects of climate on each guild. Specifically, univariate regressions showed that seed herbivory increased at higher latitudes and with colder temperatures, while leaf herbivory increased toward the equator and with wetter conditions. Multiple regressions including temperature, precipitation and latitude only found significant effects of temperature for seed herbivory and latitude for leaf herbivory. Accordingly, that latitudinal variation in seed herbivory appears to be driven predominantly by variation in temperature whereas latitudinal variation in leaf herbivory was apparently driven by other unexplored correlates of latitude. Parasitism did not exhibit variation with latitude or climatic factors. Overall, these findings underscore that the factors driving latitudinal clines in herbivory might vary even among herbivore species coexisting on the same host plant.     

Experimental Production of Lethal Escherichia coli Bacteremia of Pelvic Origin

To reproduce the syndrome of overwhelming Escherichia coli bacteremia and shock after pelvic instrumentation, a model was developed by feeding E. coli via drinking water to coliform-free rabbits, injecting nitrogen mustard intravenously, and inserting a temperature probe into the rectum. The temperature probe was inserted to mimic pelvic instrumentation of patients and to detect fever. Rabbits fed invasive serotypes of E. coli all suffered overwhelming bacteremia with high fever and fatal vascular collapse secondary to invasion of pelvic veins as the granulocyte count approached zero. In the absence of granulocytopenia, the rectal temperature probe produced an intensive inflammation with numerous polymorphonuclears and bacteremia did not develop. In the absence of rectal probing, granulocytopenic rabbits developed high fever without bacteremia. This model resembles human bacteremic shock with respect to the endogenous source of the bacteria, the high frequency of bacteremia due to E. coli and other enteric bacilli, the importance of pelvic instrumentation, and the associated immune disturbances such as granulocytopenia.