Vascularization inside the epidermis of Neotropical anurans (Nobleobatrachia).

Anuran skin is a dynamic organ involved in essential functions that strongly correlate with specific morphological traits. Particularly, gas exchange has been associated with epidermal modifications, such as reduced cell layers and increased vascularization. Here, we describe the epidermal morphology and its association with capillary networks in the dorsal skin of 103 Neotropical anurans (Nobleobatrachia) from different ecomorphs and habitats. Additionally, we examined the lateral and ventral skin for a subset of these species. We report intraepidermal capillaries in (i) dorsal skin of Lepidobatrachus laevis and Lepidobatrachus llanensis (burrowing and semi-aquatic Chacoan species), Hyloscirtus colymba and Hyloscirtus palmeri (arboreal species from humid forests), and Alsodes neuquensis and 15 Telmatobius spp. (aquatic and semi-aquatic species from cold environments); (ii) lateral skin of Boana benitezi and H. colymba (arboreal species from humid forests), and (iii) ventral skin of B. benitezi, H. colymba, Atelognathus patagonicus (aquatic species from cold environments), and four Chacoan species, Chacophrys pierottii, Ceratophrys cranwelli (burrowing/terrestrial species), and Lepidobatrachus asper and L. llanensis (burrowing/semi-aquatic species). Also, verrucae hydrophilicae were observed exclusively in the ventral skin of Leptodactylus fuscus, Leptodactylus laticeps (terrestrial and Chacoan species), and B. benitezi. Regardless of the skin region, the capillaries always penetrate the epidermis from the dermis, while epidermal cell layers are flattened. Our findings support previous hypotheses stating that the environment where species occur influences skin changes related to cutaneous respiration (intraepidermal capillaries in different body regions) and water absorption (intraepidermal capillaries associated with verrucae hydrophilicae within ventral skin). Also, phylogeny might influence the development of these structures, as revealed by the presence of intraepidermal capillaries in almost all analyzed species of Telmatobius. Finally, the co-occurrence of verrucae hydrophilicae in the ventral skin of hylids from humid forests, and leptodactylids from the subhumid Chacoan region suggest an independent origin.

Bacteriemia por Pseudomonas putida en niños: serie de casos / Pseudomonas putida bacteremia in pediatric patients: A case series study

Introducción: Las bacterias del género Pseudomonas actúan como patógenos oportunistas. Pseudomonas putida se ha considerado un patógeno de baja virulencia y sensible a múltiples antibióticos, pero en los últimos años han emergido cepas resistentes. El objetivo de este estudio es describir las características clínicas, la evolución y la resistencia antibiótica de episodios de bacteriemia por P. putida en pacientes pediátricos internados. Métodos: Serie de casos retrospectiva. Se incluyeron pacientes pediátricos internados en el Hospital Prof. Dr. Juan P. Garrahan de la Ciudad de Buenos Aires, Argentina, con aislamiento en hemocultivos de P. putida, entre agosto de 2015 y agosto de 2020. Resultados: Muestra formada por 13 pacientes. Mediana de edad: 81 meses (RIC 15-163 meses). Diez pacientes eran inmunodeprimidos (77%), 11 (85%) tenían catéter venoso central, 2 (15%) recibieron transfusiones antes del episodio de bacteriemia y 6 (46%) habían tenido algún procedimiento invasivo en los 30 días previos. Tres pacientes (23%) presentaron bacteriemia secundaria a foco clínico y 10 (77%) bacteriemia asociada a catéter venoso central. Todos presentaron fiebre, el 62% (8) evolucionó con sepsis y el 15% (2) con shock séptico. Dos pacientes requirieron ingreso en la unidad de cuidados intensivos (15%), y en 7 (54%) se retiró el catéter venoso central. Ninguno falleció. La mediana de días de tratamiento fue de 14 (RIC 10-14). La resistencia a carbapenémicos fue del 30%. Conclusión: Todos los niños tuvieron comorbilidades subyacentes, en su mayoría inmunodepresión. Predominó la infección asociada a catéter. La sensibilidad a los antibióticos fue variable. Ante la emergencia de cepas multirresistentes, es fundamental conocer la epidemiología local.(AU)

Introduction: Bacteria of the genus Pseudomonas act as opportunistic pathogens. Pseudomonas putida has been considered a pathogen of low virulence and susceptible to multiple antibiotics, but in recent years resistant strains have emerged. The objective of this study is to describe the clinical characteristics, evolution and antibiotic resistance of P. putida bacteremia documented in pediatric hospitalized patients. Methods: Retrospective cases series. Pediatric patients admitted to the Prof. Dr. Juan P. Garrahan Hospital of Buenos Aires City, Argentina, with isolation in blood cultures of P. putida were included, between August 2015 and August 2020. Results: Sample consisting of 13 patients. Median age: 81 months (IQR 15-163). Ten of the patients were immunocompromised (77%), 11 (85%) had a central venous catheter, 2 (15%) received transfusions prior to the episode of bacteremia, and 6 (46%) had had an invasive procedure within the previous 30 days. Three patients (23%) presented bacteremia secondary to clinical focus and 10 (77%) had central venous catheter-associated bacteremia. All presented fever, 62% (8) evolved with sepsis and 15% (2) with septic shock. Two patients required admission to the intensive care unit (15%), and in 7 (54%) the central venous catheter was removed. None died. The median days of treatment was 14 (IQR 10-14). Resistance to carbapenems was 30%. Conclusion: All children had underlying comorbidities, most of them immunocompromised. Catheter-associated infection predominated. The sensitivity to antibiotics was variable. Given the emergence of multi-resistant strains, it is essential to know the local epidemiology.(AU)

Pseudomonas putida bacteremia in pediatric patients: A case series study.

INTRODUCTION: Bacteria of the genus Pseudomonas act as opportunistic pathogens. Pseudomonas putida has been considered a pathogen of low virulence and susceptible to multiple antibiotics, but in recent years resistant strains have emerged. The objective of this study is to describe the clinical characteristics, evolution and antibiotic resistance of P. putida bacteremia documented in pediatric hospitalized patients. METHODS: Retrospective cases series. Pediatric patients admitted to the Prof. Dr. Juan P. Garrahan Hospital of Buenos Aires City, Argentina, with isolation in blood cultures of P. putida were included, between August 2015 and August 2020. RESULTS: Sample consisting of 13 patients. Median age: 81 months (IQR 15-163). Ten of the patients were immunocompromised (77%), 11 (85%) had a central venous catheter, 2 (15%) received transfusions prior to the episode of bacteremia, and 6 (46%) had had an invasive procedure within the previous 30 days. Three patients (23%) presented bacteremia secondary to clinical focus and 10 (77%) had central venous catheter-associated bacteremia. All presented fever, 62% (8) evolved with sepsis and 15% (2) with septic shock. Two patients required admission to the intensive care unit (15%), and in 7 (54%) the central venous catheter was removed. None died. The median days of treatment was 14 (IQR 10-14). Resistance to carbapenems was 30%. CONCLUSION: All children had underlying comorbidities, most of them immunocompromised. Catheter-associated infection predominated. The sensitivity to antibiotics was variable. Given the emergence of multi-resistant strains, it is essential to know the local epidemiology.

Carbapenem-resistant Enterobacteriaceae bloodstream infections: A case-control study from a pediatric referral hospital in Argentina.

Background: Antibiotic-resistant gram-negative bloodstream infections (BSI) remain a leading cause morbidity and mortality in pediatric patients with a high impact on the public health system. Data in resource-limited countries, including those in Latin America and the Caribbean region, are scarce. The aim of the study was to identify risk factors for acquiring carbapenem-resistant Enterobacteriaceae (CRE) bacteremia in children and to assess the use of resources. Methods: A retrospective case-control study was conducted to analyze demographic, epidemiological, clinical, microbiological, and outcome data as well as the use of resources between 2014 and 2019. Univariate and logistic regression analysis was performed in order to identify risk factors associated with CRE-BSI. The R software version 4.1.2 was used. Results: A total of 46 cases with CRE-BSI and 92 controls with gram-negative non-CRE-BSI were included. No statistical difference was observed regarding: median age (36 months; IQR, 11.2-117 vs. 48 months, IQR 13-119), male sex (50 vs. 60%), and underlying disease (98 vs. 91%) in cases vs. controls, respectively. The most frequent mechanism of CRE bacteremia were: KPC in 74%, OXA in 15%, and NDM in 6.5%. A total of 54.3% of cases vs. 32.6 % (p = 0.016) of controls were admitted to the pediatric intensive care unit (PICU), and 48 vs. 21% (p = 0.001) required mechanical ventilation. Bacteremia secondary to intra-abdominal infection was observed in 56.5% of cases vs. 35% of controls (p = 0.032). Previous colonization with CRE was detected in 76% of cases vs. 8% of controls. Combination antimicrobial treatment was most frequent in cases vs. control (100 vs. 56.5%). No difference was observed in median length of hospital stay (22 days; IQR, 19-31 in cases vs. 17.5 days; IQR, 10-31 in controls; p = 0.8). Overall case fatality ratio was 13 vs. 5.5%, respectively. The most statistically significant risk factors included previous PICU stay (OR, 4; 95%CI, 2-8), invasive procedures/surgery (OR, 3; 95%CI, 1-7), central venous catheter placement (OR, 6.5; 95%CI, 2-19), urinary catheter placement (OR, 9; 95%CI 4-20), mechanical ventilation (OR, 4; 95%CI, 2-10), liver transplantation (OR, 8; 95%CI, 2-26), meropenem treatment (OR, 8.4; 3.5-22.6) in univariate analysis. The logistic regression model used for multivariate analysis yielded significant differences for previous meropenem treatment (OR, 13; 95%CI, 3-77; p = 0.001), liver transplantation (OR, 13; 95%CI, 2.5-100; p = 0.006), and urinary catheter placement (OR, 9; 95%CI, 1.4-94; p = 0.03). Conclusion: CRE-BSI affects hospitalized children with underlying disease, mainly after liver transplantation, with previous urinary catheter use and receiving broad-spectrum antibiotics, leading to high PICU requirement and mortality. These risk factors will have to be taken into account in our region in order to establish adequate health policies and programs to improve antimicrobial stewardship.

Combined phylogenetic analysis of Pleurodema (Anura: Leptodactylidae: Leiuperinae).

The genus Pleurodema comprises 15 species distributed through the Neotropical region, from sea level up to 5000 m.a.s.l. A total-evidence analysis of Pleurodema is provided based on the parsimony criterion. The combined dataset included morphometric, phenotypic, and DNA evidence (34 taxa, 4441 characters). The parsimony analysis yielded one most-parsimonious tree. Pleurodema was recovered as a well-supported clade composed of two major subclades. One subclade has an identical topology to that of previous analyses, the P. brachyops Clade (P. alium, P. borellii, P. brachyops, P. cinereum, P. diplolister, and P. tucumanum). The other subclade includes the remaining nine species of the genus, exhibiting a topology different from that of previous studies. According to the present phylogeny, this second lineage is formed by the P. nebulosum Clade (P. guayapae + P. nebulosum), P. marmoratum, the re-defined P. thaul Clade (P. bufoninum, P. somuncurense, P. thaul) and the P. bibroni Clade (P. bibroni, P. cordobae, P. kriegi). The reproductive modes of Pleurodema represent a unique combination of features within Leiuperinae, including three egg-clutch structures, two types of amplexus, and lack of vocalization. Also, some species of Pleurodema have been considered fossorial, because they are capable of digging with their hind-limbs and remaining in self-made burrows during dry seasons. The evolution of characters associated with reproductive biology and fossoriality is discussed in light of the obtained results.

Infección de piel y tejidos blandos por Burkholderia stabilis en un niño con quemaduras graves / Skin and soft tissue infection due to Burkholderia stabilis in a severely burned child

Resumen Las heridas por quemadura representan un grave problema, sobre todo en la población pediátrica, dada la severidad de su presentación y la morbimortalidad asociada. La infección es la complicación más frecuente y grave en el paciente quemado. Las bacterias que conforman el complejo Burkholderia cepacia (CBc) son capaces de causar enfermedades en plantas, humanos y animales. En el hombre pueden establecer infecciones crónicas y frecuentemente graves, por lo general en pacientes con fibrosis quística y en inmunocomprometidos. El CBc está compuesto por al menos 22 especies filogenéticamente muy relacionadas. El objetivo de esta publicación fue describir el primer caso de una infección de piel y partes blandas por Burkholderia stabilis, una especie poco frecuente, en un niño con grandes quemaduras en la Argentina. Las especies del CBc son intrínsecamente resistentes a la mayoría de los antimicrobianos disponibles clínicamente, como aminoglucósidos, quinolonas, polimixinas y β-lactámicos. Esto representa un serio problema en el momento de tratar las infecciones por las escasas opciones terapéuticas.

Abstract Burn wounds represent a serious problem, especially in the pediatric population, given the severity of their presentation and the associated morbidity and mortality. Infection is the most frequent and serious complication in the burned patient. Burkholderia cepacia (CBc) complex bacteria are capable of causing disease in plants, humans, and animals. In human beings they can establish chronic and frequently serious infections, generally in patients with cystic fibrosis and in immunocompromised patients. The CBc is composed of 22 phylogenetically closely related species. The objective of this publication was to describe the first report of a skin and soft tissue infection by Burkholderia stabilis, a rare species, in a child with extensive burns in Argentina. CBc species are inherently resistant to most clinically available antimicrobials, such as aminoglycosides, quinolones, polymyxins, and β-lactams. This represents a serious problem when treating infections, due to the limited therapeutic options.

Resumo As feridas por queimadura representam um grave problema, principalmente na população pediátrica, devido à gravidade de sua apresentação e morbimortalidade associada. A infecção é a complicação mais frequente e grave do paciente queimado. As bactérias que compõem o complexo Burkholderia cepacia (CBc) são capazes de causar doenças em plantas, humanos e animais. No homem, podem estabelecer infecções crônicas e freqüentemente graves, geralmente em pacientes com fibrose cística e imunocomprometidos. O CBc é composto, no mínimo, por 22 espécies filogeneticamente muito relacionadas. O objetivo desta publicação é descrever o primeiro caso de uma infecção de pele e tecidos moles por Burkholderia stabilis, uma espécie rara, em uma criança com queimaduras extensas na Argentina. As espécies do CBc são inerentemente resistentes à maioria dos antimicrobianos disponíveis clinicamente, como aminoglicosídeos, quinolonas, polimixinas e β-lactâmicos. Isso representa um problema sério na hora de tratar as infecções devido às opções terapêuticas limitadas.

[Epidemiological characteristics according to the progress of SARS-CoV-2 pandemic in a highly complex pediatric hospital in Argentina: a descriptive study]. / Características epidemiológicas según el avance de la pandemia SARS-CoV-2 en un hospital pediátrico de alta complejidad en Argentina: estudio descriptivo.

BACKGROUND: The knowledge of the clinical and evolutionary characteristics of children with SARS-CoV-2 is continuously updated. The true impact of the disease in the pediatric population is still unknown. AIM: To describe the clinical characteristics, the use of resources and the evolution of children with COVID-19 in the Garrahan Pediatric Hospital, Buenos Aires, Argentina, in the first 20 weeks from the identification of the first case. METHODS: Descriptive, analytical, retrospective study. The epidemiological, clinical, evolutionary characteristics and the use of hospital resources of patients < 18 years with confirmed COVID-19 are described. In addition, these characteristics were compared according to whether they occurred in the first 10 epidemiological weeks from the first case of COVID-19 in the hospital or in the following ten weeks. RESULTS: n: 280. The median age was 83 months (IQR 33-144). 209 patients (74.6%) were hospitalized. The median days of hospitalization was 8 days (IQR 3-13). According to the WHO severity classification, there were 184 mild cases (65.7%), 3 moderate (1.1%), 16 severe (5.7%) and 20 critical patients (7.1%). The main reasons for admission to the ICU were not related to SARS-CoV-2 infection. When comparing the characteristics of the patients in the two periods, in the first period there was a higher frequency of underlying comorbidities, immunosuppressive treatment, the consultation was later and the patients had more requirements for ICU admission. Two children (0.7%) died in relation to the infection, both with severe comorbidities and severe bacterial coinfections. CONCLUSION: In this study, patients with underlying disease predominated. The mild form of the disease was the most frequent presentation. At the beginning of the pandemic, there were more patients under immunosuppressive treatment, the consultation was later and the hospitalization was more frequent, prolonged and with more serious clinical pictures.

Características epidemiológicas según el avance de la pandemia SARS-CoV-2 en un hospital pediátrico de alta complejidad en Argentina: estudio descriptivo / Epidemiological characteristics according to the progress of SARS-CoV-2 pandemic in a highly complex pediatric hospital in Argentina: a descriptive study

INTRODUCCIÓN: El conocimiento de las características clínicas y evolutivas de los niños con SARS-CoV-2 está siendo continuamente actualizado. El verdadero impacto de la enfermedad en la población pediátrica es todavía desconocido. OBJETIVO: Describir las características clínicas, el uso de recursos y la evolución de niños con COVID-19 en el Hospital de Pediatría Garrahan, Buenos Aires, Argentina, en las primeras 20 semanas desde la identificación del primer caso. PACIENTES Y MÉTODOS: Estudio descriptivo analítico, retrospectivo. Se describen las características epidemiológicas, clínicas, evolutivas y el uso de recursos hospitalarios de pacientes < 18 años con COVID-19 confirmado. Además, se compararon dichas características según se presentaran en las primeras 10 semanas epidemiológicas desde el primer caso de COVID-19 en el hospital o en las 10 siguientes. RESULTADOS: n: 280. La mediana de edad fue 83 meses (RIC 33-144). Fueron hospitalizados 209 pacientes (74,6 %). La mediana de días de internación fue de 8 días (RIC 3-13). Según la clasificación de gravedad de la OMS, fueron casos leves 184 (65,7%), moderados 3 (1,1%), graves 16 (5,7%) y 20 pacientes críticos (7,1%). Los principales motivos de ingreso a UCI no se relacionaron con la infección por SARS-CoV-2. Al comparar las características de los pacientes en los dos períodos, en el primer período hubo más frecuencia de comorbilidades subyacentes, tratamiento inmunosupresor, la consulta fue más tardía y los pacientes tuvieron más requerimientos de internación en UCI. Fallecieron en relación con la infección dos niños (0,7%), ambos con comorbilidades graves y coinfecciones bacterianas graves. CONCLUSIÓN: En este estudio predominaron los pacientes con enfermedad de base. La forma leve de la enfermedad fue la presentación más frecuente. Al inicio de la pandemia, hubo más pacientes bajo tratamiento inmunosupresor, la consulta fue más tardía y la internación fue más frecuente, prolongada y con cuadros clínicos más graves.

BACKGROUND: The knowledge of the clinical and evolutionary characteristics of children with SARS-CoV-2 is continuously updated. The true impact of the disease in the pediatric population is still unknown. AIM: To describe the clinical characteristics, the use of resources and the evolution of children with COVID-19 in the Garrahan Pediatric Hospital, Buenos Aires, Argentina, in the first 20 weeks from the identification of the first case. METHODS: Descriptive, analytical, retrospective study. The epidemiological, clinical, evolutionary characteristics and the use of hospital resources of patients < 18 years with confirmed COVID-19 are described. In addition, these characteristics were compared according to whether they occurred in the first 10 epidemiological weeks from the first case of COVID-19 in the hospital or in the following ten weeks. RESULTS: n: 280. The median age was 83 months (IQR 33-144). 209 patients (74.6%) were hospitalized. The median days of hospitalization was 8 days (IQR 3-13). According to the WHO severity classification, there were 184 mild cases (65.7%), 3 moderate (1.1%), 16 severe (5.7%) and 20 critical patients (7.1%). The main reasons for admission to the ICU were not related to SARS-CoV-2 infection. When comparing the characteristics of the patients in the two periods, in the first period there was a higher frequency of underlying comorbidities, immunosuppressive treatment, the consultation was later and the patients had more requirements for ICU admission. Two children (0.7%) died in relation to the infection, both with severe comorbidities and severe bacterial coinfections. CONCLUSION: In this study, patients with underlying disease predominated. The mild form of the disease was the most frequent presentation. At the beginning of the pandemic, there were more patients under immunosuppressive treatment, the consultation was later and the hospitalization was more frequent, prolonged and with more serious clinical pictures.

How sensitive are temperate tadpoles to climate change? The use of thermal physiology and niche model tools to assess vulnerability.

Ectotherms are vulnerable to climate change, given their dependence on temperature, and amphibians are particularly interesting because of their complex life cycle. Tadpoles may regulate their body temperature by using suitable thermal microhabitats. Thus, their physiological responses are the result of adjustment to the local thermal limits experienced in their ponds. We studied three anuran tadpole species present in Argentina and Chile: Pleurodema thaul and Pleurodema bufoninum that are seasonal and have broad geographic ranges, and Batrachyla taeniata, a geographically restricted species with overwintering tadpoles. Species with restricted distribution are more susceptible to climate change than species with broader distribution that may cope with potential climatic changes in the environments in which they occur. We aim to test whether these species can buffer the potential effects of climate warming. We used ecological niche models and the outcomes of their thermal attributes (critical thermal limits, optimal temperature, and locomotor performance breadth) as empirical evidence of their capacity. We found that Pleurodema species show broader performance curves, related to their occurrence, while the geographically restricted B. taeniata shows a narrower thermal breadth, but is faster in warmer conditions. The modeled distributions and empirical physiological results suggest no severe threats for these three anurans. However, the risk level is increasing and a retraction of their distribution range might be possible for Pleurodema species, and some local population extinctions may happen, particularly for the narrowly distributed B. taeniata.

A comparative ultrastructural analysis of spermatozoa in Pleurodema (Anura, Leptodactylidae, Leiuperinae).

This study describes the spermatozoa of 10 of the 15 species of the Neotropical frog genus Pleurodema through transmission electron microscopy. The diversity of oviposition modes coupled with a recent phylogenetic hypothesis of Pleurodema makes it an interesting group for the study of ultrastructural sperm evolution in relation to fertilization environment and egg-clutch structure. We found that Pleurodema has an unusual variability in sperm morphology. The more variable structures were the acrosomal complex, the midpiece, and the tail. The acrosomal complex has all the structures commonly reported in hyloid frogs but with different degree of development of the subacrosomal cone. Regarding the midpiece, the variability is given by the presence or absence of the mitochondrial collar. Finally, the tail is the most variable structure, ranging from single (only axoneme) to more complex (presence of paraxonemal rod, cytoplasmic sheath, and undulating membrane), with the absence of the typical axial fiber present in hyloid frogs, also shared with some other genera of Leiuperinae. J. Morphol. 277:957-977, 2016. © 2016 Wiley Periodicals, Inc.

The identity of Rana lutea Molina, 1782 (Amphibia, Anura).

Rana lutea is one of the two anuran species described in 1782 by the Chilean born priest and naturalist Juan Ignacio Molina, and its nomenclatural history is confusing. After a detailed revision of the pertinent literature, we demonstrate that Bufo thaul Schneider, 1799, is a junior objective synonym of Rana lutea Molina, 1782, but based on the usage of both nomina, we revert the precedence and consider Rana lutea Molina, 1782 as a nomen oblitum whereas Bufo thaul Schneider, 1799 is a nomen protectum. Thus, the authorship of the species currently known as Pleurodema thaul (Lesson, 1826) changes to Pleurodema thaul (Schneider, 1799).

A phylogenetic analysis of Pleurodema (Anura: Leptodactylidae: Leiuperinae) based on mitochondrial and nuclear gene sequences, with comments on the evolution of anuran foam nests.

Species of the genus Pleurodema are relatively small, plump frogs that mostly occur in strong-seasonal and dry environments. The genus currently comprises 14 species distributed from Panama to southern Patagonia. Here we present a phylogenetic analysis of Pleurodema, including all described species and several outgroups. Our goals include testing its monophyly and the monophyly of the species groups that were historically proposed, and studying the evolution of some character systems, particularly macroglands and egg-clutch structure; this last point also provided the chance for a discussion of foam nest evolution in anurans. Our dataset includes portions of the mitochondrial genes cytochromeb, 12S, 16S, and the intervening tRNAVal ; the nuclear gene sequences include portions of rhodopsin exon 1 and seven in absentia homolog I. Our results support a clade composed of Pleurodema and including the monotypic SomuncuriaLynch, 1978 nested within it. The latter genus is therefore considered a junior synonym of Pleurodema and its sole species is added to this genus. Furthermore, our results indicate the non-monophyly of several species groups proposed previously. We recognize four clades in Pleurodema: the P. bibroni clade (P. bibroni, P. cordobae and P. kriegi), the P. thaul clade (P. bufoninum, P. marmoratum, P. somuncurensis and P. thaul), the P. brachyops clade (P. alium, P. borellii, P. brachyops, P. cinereum, P. diplolister and P. tucumanum) and the P. nebulosum clade (P. guayapae and P. nebulosum). Our results further indicate the need for a taxonomic reassessment of P. borellii and P. cinereum (as did previous studies), P. guayapae and P. nebulosum, and the three species in the P. bibroni clade. Pleurodema shows a striking pattern of variation in presence/absence of lumbar glands. Our results indicate multiple losses or independent gains of this character associated with defensive displays. The reproductive modes of Pleurodema include four different egg-clutch structures. The optimization of these indicates that there are at least two independent transformations from the plesiomorphic mode of foam nests to egg-clutch structures involving gelatinous masses of different sorts (ovoid plates, masses, or strings). We hypothesize that these independent transformations could involve changes at the behavioural (the loss of foam beating behaviour by the parent) and/or structural level (transformations involving the pars convoluta dilata, the section of the oviduct where the foam-making substance is secreted). Finally, our study of foam nest evolution in Pleurodema is extended to the other groups of anurans where foam-nesting occurs, on the basis of available data and recent phylogenetic hypotheses. In the different hyloid groups where it occurs, foam-nesting evolved from clutches laid in water. However, in all ranoids in which foam-nesting occurs, it evolved from terrestrial clutches, with eggs laid hanging in vegetation, or, if the clutches are laid on a restricted volume of water, involving endotrophic development. © The Willi Hennig Society 2012.