Characteristics and function of the gut microbiota in patients with IgA nephropathy via metagenomic sequencing technology.

OBJECTIVE: The aim of this study was to investigate the characteristics and related functional pathways of the gut microbiota in patients with IgA nephropathy (IgAN) through metagenomic sequencing technology. METHODS: We enrolled individuals with primary IgAN, including patients with normal and abnormal renal function. Additionally, we recruited healthy volunteers as the healthy control group. Stool samples were collected, and species and functional annotation were performed through fecal metagenome sequencing. We employed linear discriminant analysis effect size (LEfSe) analysis to identify significantly different bacterial microbiota and functional pathways. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was used to annotate microbiota functions, and redundancy analysis (RDA) was performed to analyze the factors affecting the composition and distribution of the gut microbiota. RESULTS: LEfSe analysis revealed differences in the gut microbiota between IgAN patients and healthy controls. The characteristic microorganisms in the IgAN group were classified as Escherichia coli, with a significantly greater abundance than that in the healthy control group (p < 0.05). The characteristic microorganisms in the IgAN group with abnormal renal function were identified as Enterococcaceae, Moraxella, Moraxella, and Acinetobacter. KEGG functional analysis demonstrated that the functional pathways of the microbiota that differed between IgAN patients and healthy controls were related primarily to bile acid metabolism. CONCLUSIONS: The status of the gut microbiota is closely associated not only with the onset of IgAN but also with the renal function of IgAN patients. The characteristic gut microbiota may serve as a promising diagnostic biomarker and therapeutic target for IgAN.

Cross-transmission of Acinetobacter junii carrying blaOXA-58 in a neonatal ICU.

BACKGROUND: Nasal colonization of two preterm infants in our neonatal ICU by Acinetobacter junii carrying the blaOXA-58 carbapenem resistance gene was demonstrated. OBJECTIVES: To study whether the two isolates were identical and to investigate the hypotheses of cross-transmission. METHODS: Antibiotic susceptibility tests of the two isolates were performed by standard diffusion and the MICs of carbapenems determined by the MIC-gradient strip method. The blaOXA-58 gene was detected by PCR. Isolates were compared using SNP analysis performed after WGS. The timelines of the two cases were determined based on the investigations and the study of the patients' records. RESULTS: The two isolates corresponded to the same strain, with case 1 being the index case, demonstrating cross-transmission to case 2. CONCLUSIONS: Acquisition of the strain was likely due to the recent carbapenem treatment of case 1 and cross-transmission due to the high amount of care administered to the two preterm infants. This is the first description of cross-transmission of A. junii carrying the blaOXA-58 gene.

Microbial Contamination of Dental Unit Waterlines among Dental Clinics of India- An In vitro Study.

BACKGROUND: Dental Unit Water Line (DUWL) deliver water to different handpieces in a dental unit. The water in DUWL circulates in a closed system, where it is taken from a container. The quality of dental water is of considerable importance since patients and dental staff are regularly exposed to water and aerosols generated from dental equipment. Output water from DUWLs may be a potential source of infection for both dental health care personnel and patients. AIM: To assess the microbial contamination in the DUWL among dental clinics in Chennai. MATERIALS AND METHODS: An in vitro study was conducted on 60 water samples from 20 dental clinics in Chennai in December 2019. Water samples were collected from three different sources of the Dental unit according to ADA guidelines. The collected samples were assessed for the presence of Aspergillus, Acinetobacter, Pseudomonas aeruginosa, and Legionella by agar plate method. The data were analysed using SPSS software version 20. RESULTS: Legionella was the most prevalent microorganism with 70% prevalence in a three-way syringe and 50% in scaler and airotor, followed by Pseudomonas aeruginosa and Acinetobacter with 10% prevalence in scaler and airotor and Aspergillus with a prevalence of 10% in the three-way syringe. CONCLUSION: Most of the dental units were contaminated with Aspergillus, Legionella, Pseudomonas aeruginosa and Acinetobacter which pose a serious threat to the patients as well as the dentists.

Four novel Acinetobacter lwoffii strains isolated from the milk of cows in China with subclinical mastitis.

BACKGROUND: Acinetobacter lwoffii (A. lwoffii) is a Gram-negative bacteria common in the environment, and it is the normal flora in human respiratory and digestive tracts. The bacteria is a zoonotic and opportunistic pathogen that causes various infections, including nosocomial infections. The aim of this study was to identify A. lwoffii strains isolated from bovine milk with subclinical mastitis in China and get a better understanding of its antimicrobial susceptibility and resistance profile. This is the first study to analyze the drug resistance spectrum and corresponding mechanisms of A. lwoffii isolated in raw milk. RESULTS: Four A. lwoffii strains were isolated by PCR method. Genetic evolution analysis using the neighbor-joining method showed that the four strains had a high homology with Acinetobacter lwoffii. The strains were resistant to several antibiotics and carried 17 drug-resistance genes across them. Specifically, among 23 antibiotics, the strains were completely susceptible to 6 antibiotics, including doxycycline, erythromycin, polymyxin, clindamycin, imipenem, and meropenem. In addition, the strains showed variable resistance patterns. A total of 17 resistance genes, including plasmid-mediated resistance genes, were detected across the four strains. These genes mediated resistance to 5 classes of antimicrobials, including beta-lactam, aminoglycosides, fluoroquinolones, tetracycline, sulfonamides, and chloramphenicol. CONCLUSION: These findings indicated that multi-drug resistant Acinetobacter lwoffii strains exist in raw milk of bovine with subclinical mastitis. Acinetobacter lwoffii are widespread in natural environmental samples, including water, soil, bathtub, soap box, skin, pharynx, conjunctiva, saliva, gastrointestinal tract, and vaginal secretions. The strains carry resistance genes in mobile genetic elements to enhance the spread of these genes. Therefore, more attention should be paid to epidemiological surveillance and drug resistant A. lwoffii.

The nasal microbiota is a potential diagnostic biomarker for sepsis in critical care units.

This study aimed to characterize the composition of intestinal and nasal microbiota in septic patients and identify potential microbial biomarkers for diagnosis. A total of 157 subjects, including 89 with sepsis, were enrolled from the affiliated hospital. Nasal swabs and fecal specimens were collected from septic and non-septic patients in the intensive care unit (ICU) and Department of Respiratory and Critical Care Medicine. DNA was extracted, and the V4 region of the 16S rRNA gene was amplified and sequenced using Illumina technology. Bioinformatics analysis, statistical processing, and machine learning techniques were employed to differentiate between septic and non-septic patients. The nasal microbiota of septic patients exhibited significantly lower community richness (P = 0.002) and distinct compositions (P = 0.001) compared to non-septic patients. Corynebacterium, Staphylococcus, Acinetobacter, and Pseudomonas were identified as enriched genera in the nasal microbiota of septic patients. The constructed machine learning model achieved an area under the curve (AUC) of 89.08, indicating its efficacy in differentiating septic and non-septic patients. Importantly, model validation demonstrated the effectiveness of the nasal microecological diagnosis prediction model with an AUC of 84.79, while the gut microecological diagnosis prediction model had poor predictive performance (AUC = 49.24). The nasal microbiota of ICU patients effectively distinguishes sepsis from non-septic cases and outperforms the gut microbiota. These findings have implications for the development of diagnostic strategies and advancements in critical care medicine.IMPORTANCEThe important clinical significance of this study is that it compared the intestinal and nasal microbiota of sepsis with non-sepsis patients and determined that the nasal microbiota is more effective than the intestinal microbiota in distinguishing patients with sepsis from those without sepsis, based on the difference in the lines of nasal specimens collected.

Acinetobacter in fresh faecal samples is related to sperm motility: A case report in Piétrain boars housed on different deep-litter bedding materials.

The swine gastrointestinal tract contains a great variety of microbes, forming a complex and dynamic ecosystem. Various internal and external factors (e.g. age, breed and diet) may influence its composition. This study aimed to investigate the gut microbial diversity of German Piétrain boars housed on different deep-litter bedding materials (regional wood shavings, linen, hemp, spelt husks, and wood shavings) via 16S-rDNA sequencing. Additionally, short-chain fatty acids were analysed using gas chromatography. Fresh faecal samples (n = 80) from 40 Piétrain boars were collected twice during the trial. Although it can be assumed that boars ingest bedding orally, no differences in the microbiome composition could be found. The main phyla were Firmicutes and Bacteroides. Acinetobacter was identified as a biomarker for sperm quality differences (total sperm motility) in breeding boars.

Acinetobacter junii: an emerging One Health pathogen.

Acinetobacter junii is an opportunistic human and animal pathogen severely understudied. Here, we conducted the largest genomic epidemiological study on this pathogen to date. Our data show that this bacterium has spread globally. Also, we found that some human and non-human isolates are not well differentiated from one another, implying transmission between clinical and non-clinical, non-human settings. Remarkably, human but also some non-human isolates have clinically important antibiotic resistance genes, and some of these genes are located in plasmids. Given these results, we put forward that A. junii should be considered an emerging One Health problem. In this regard, future molecular epidemiological studies about this species will go beyond human isolates and will consider animal-, plant-, and water-associated environments. IMPORTANCE: Acinetobacter baumannii is the most well-known species from the genus Acinetobacter. However, other much less studied Acinetobacter species could be important opportunistic pathogens of animals, plants and humans. Here, we conducted the largest genomic epidemiological study of A. junii, which has been described as a source not only of human but also of animal infections. Our analyses show that this bacterium has spread globally and that, in some instances, human and non-human isolates are not well differentiated. Remarkably, some non-human isolates have important antibiotic resistance genes against important antibiotics used in human medicine. Based on our results, we propose that this pathogen must be considered an issue not only for humans but also for veterinary medicine.

Carbapenemase genes in clinical and environmental isolates of Acinetobacter spp. from Quito, Ecuador.

Carbapenem-resistant Acinetobacter spp. is associated with nosocomial infections in intensive care unit patients, resulting in high mortality. Although Acinetobacter spp. represent a serious public health problem worldwide, there are a few studies related to the presence of carbapenemases in health care facilities and other environmental settings in Ecuador. The main aim of this study was to characterize the carbapenem-resistant Acinetobacter spp. isolates obtained from four hospitals (52) and from five rivers (27) close to Quito. We used the disc diffusion and EDTA sinergy tests to determine the antimicrobial susceptibility and the production of metallo ß-lactamases, respectively. We carried out a multiplex PCR of gyrB gene and the sequencing of partial rpoB gene to bacterial species identification. We performed molecular screening of nine carbapenem-resistant genes (blaSPM, blaSIM, blaGIM, blaGES, blaOXA-23, blaOXA-24, blaOXA-51, blaOXA-58, and blaOXA-143) by multiplex PCR, followed by identification using sequencing of blaOXA genes. Our findings showed that carbapenem-resistant A. baumannii were the main species found in health care facilities and rivers. Most of the clinical isolates came from respiratory tract samples and harbored blaOXA-23, blaOXA-366, blaOXA-72, blaOXA-65, blaOXA-70, and blaOXA-143-like genes. The river isolates harbored only the blaOXA-51 and probably blaOXA-259 genes. We concluded that the most predominant type of carbapenem genes among isolates were both blaOXA-23 and blaOXA-65 among A. baumannii clinical isolates.

In vitro activity of the newly approved antimicrobial agent Cefiderocol against Carbapenem resistant Gram negative clinical isolates.

INTRODUCTION: Carbapenem resistant Gram negative bacteria have emerged as priority pathogens in recent years. Cefiderocol is a siderophore cephalosporin licensed in 2019 with claimed activity against ESBL producing and carbapenem resistant bacteria with much better safety margin compared to colistin. The present study was undertaken to assess the in vitro activity of cefiderocol against carbapenem resistant clinical isolates, compared to some select antimicrobial agents including colistin. MATERIALS AND METHODS: Seventy-seven isolates of Gram negative bacteria belonging to the three commonly encountered groups of Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter spp were included. Susceptibility testing for Cefiderocol was determined by Kirby-Bauer's disk diffusion technique as per CLSI guidelines using Cefiderocol disc (30 µg). Sensitivity for the other agents were determined using automated system. RESULTS: Of the 77 isolates, 58.4% belonged to Enterobacterales, followed by P.aeruginosa (27.3%) and Acinetobacter spp (14.3%). Three out of 45 Enterobacterales isolates, one out of 21 P.aeruginosa and none in the Acinetobacter group were found resistant to cefiderocol. All the isolates were intermediate sensitive (I) for colistin since the "susceptible" interpretive category has been eliminated. Tigecycline showed good activity (80.0% sensitive) against Enterobacterales followed by aztreonam (71.1% sensitive). CONCLUSION: Cefiderocol is not yet available in India and our study is possibly the second one from this country demonstrating in vitro resistance to this important antimicrobial agent. However, with a relatively better safety profile compared to colistin, cefiderocol can be an important agent to combat these highly resistant pathogens.

Multidrug-Resistant and Carbapenemase Gene-Carrying Acinetobacter colistiniresistens Isolated from Bloodstream Infection.

In this study, we investigated the antimicrobial susceptibility and molecular characteristics of antimicrobial resistance of Acinetobacter colistiniresistens strains isolated from the bloodstream using whole-genome sequencing. Clinical isolates identified as Acinetobacter baumannii and showing colistin resistance at the time of detection were collected. Antimicrobial susceptibility was determined using the VITEK2 system (bioMérieux) and Sensititre system (Thermo Fisher Scientific). Species identification and antimicrobial resistance gene searches were performed through whole-genome sequencing. Through whole-genome sequencing, three colistin-resistant strains from the bloodstream were identified as A. colistiniresistens. All three A. colistiniresistens strains were resistant to two or more antimicrobial agents except for colistin, and two of them were resistant to carbapenems. Genes involved in aminoglycoside [AAC(3)-Ⅱb, AAC(6')-Ⅰj, aadA2, ANT(3″)-Ⅱb, APH(3')-Ⅵa], macrolide (mphD, msrE), carbapenem and cephalosporin (OXA-420, VIM-2), fluoroquinolone and tetracycline (adeF), and sulfonamide (sul1, sul2) resistance were detected. We report multidrug-resistant A. colistiniresistens strains isolated from the bloodstream through whole-genome sequencing. Two strains carried carbapenemase genes, and this is the first report of VIM-2-producing A. colistiniresistens.

Infección urinaria por Acinetobacter dijkshoorniae y buena respuesta clínica al tratamiento / Urinary tract infection by Acinetobacter dijkshoorniae and good clinical response to treatment

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Reporting identification of Acinetobacter spp genomic species: A nationwide proficiency study in Spain / Capacidad de los laboratorios españoles para identificar las genoespecies de Acinetobacter spp: estudio nacional multicéntrico español

Acinetobacter baumannii is the most important genomic species of Acinetobacter from a clinical and epidemiological point of view. Nevertheless, genomic species other than A. baumannii are increasingly recognized as nosocomial pathogens. Molecular methods of identification (genotypic and proteomic assays) are more accurate and reliable and have greater discriminatory power than phenotypic methods. Eleven genomic species of Acinetobacter spp. (8 A. baumannii, 1 A. pittii, 1 A. nosocomialis and 1 A. lwoffii) with different antimicrobial resistance phenotypes and mechanisms of resistance to antimicrobial agents were sent to 48 participating Spanish centers to evaluate their ability for correct identification at the genomic species level. Identification of the genomic species was performed at the two Clinical Microbiology reference laboratories (Hospital Universitario Virgen Macarena, Seville, Spain; and Complejo Hospitalario Universitario de A Coruña, A Coruña, Spain) by partial DNA sequencing of the rpoB gene and MALDI-TOF. The mean percentage of agreement was 76.1%. Fifty percent of CC-01 (A. pittii) and 50% of CC-02 (A. nosocomialis) identification results were reported as A. baumannii. Discrepancies by type of systems used for identification were: MicroScan WA (51.1%), Vitek 2 (19.5%), MALDI-TOF (18.0%), Phoenix (4.5%), Wider (3.8%) and API 20 NE (3.0%). In conclusion, clinical microbiology laboratories must improve their ability to correctly identify the most prevalent non A. baumannii genomic species

Acinetobacter baumannii es la genoespecie de Acinetobacter más importante desde el punto de vista clínico y epidemiológico. No obstante, otras genoespecies distintas de A. baumannii están adquiriendo cada vez mayor importancia como patógeno nosocomial. Los métodos moleculares (genotípicos y proteómicos) usados para la identificación de genoespecies de Acinetobacter son más precisos, fiables, y tienen mayor poder de discriminación que los métodos fenotípicos. En este estudio se incluyen 11 genoespecies de Acinetobacter spp. (8 A. baumannii, 1 A. pittii, 1 A. nosocomialis y 1 A. lwoffii) con diferentes fenotipos de resistencia y mecanismos de resistencia antimicrobiana. Los aislados se enviaron a 48 centros españoles participantes para evaluar su capacidad para identificar correctamente la genoespecie de Acinetobacter. Las identificaciones de referencia se realizaron en 2 Laboratorios de Microbiología Clínica (Hospital Universitario Virgen Macarena, Sevilla, España; Complejo Hospitalario Universitario de A Coruña, A Coruña, España) mediante secuenciación parcial del gen rpoB y MALDI-TOF. El porcentaje medio de concordancia fue del 76,1%. El 50% de los resultados de identificación del control CC-01 (A. pittii) y el 50% de los resultados de identificación del control CC-02 (A. nosocomialis) se informaron como A. baumannii. Considerando el tipo de sistema de identificación usado las discrepancias fueron: MicroScan/WA (51,1%), Vitek 2 (19,5%), MALDI-TOF (18,0%), Phoenix (4,5%), Wider (3,8%) y API 20 NE (3,0%). En conclusión, los laboratorios españoles de microbiología clínica deben mejorar su capacidad para identificar correctamente las genoespecies de Acinetobacter distintas de A. baumannii que son más prevalentes

Effects of topical azithromycin, moxifloxacin, and povidone iodine on conjunctival bacterial flora in patients undergoing intravitreal injection / Os efeitos da azitromicina tópica, moxifloxacina e iodopovidona na flora bacteriana conjuntival em injeções intravítreas

ABSTRACT Purpose: To compare effects of 5% topical povidone iodine with prophylactic topical azithromycin and moxifloxacin on bacterial flora in patients undergoing intravitreal injection. Methods: A total of 132 patients were randomly assigned to receive treatment with azithromycin or moxifloxacin, or no treatment (control group). In total, 528 specimens were obtained at the time of admission, 4 days before intravitreal injection, 4 days after intravitreal injection, and 8 days after intravitreal injection. Samples were immediately sent to the microbiology laboratory for incubation. Results: The microorganism observed most frequently was coagulasenegative Staphylococcus (23.8%). When the results of samples obtained on Day 4 before injection were assessed, growth of coagulase-negative Staphylococcus was significantly lower in the moxifloxacin group, compared with controls (p=0.049). Acinetobacter baumannii continued to grow after administration of azithromycin (p=0.033). When the results of four days after intravitreal injection were evaluated, growth of coagulase-ne gative Staphylococcus was higher in controls, compared with patients who received azithromycin or moxifloxacin (p=0.004). Eradication rate was significantly higher in the moxifloxacin group than in the control group (p=0.001). Samples obtained on Day 8 after intravitreal injection showed similar levels of bacterial growth in all groups (p=0.217). Conclusion: Moxifloxacin was more effective than 5% povidone iodine in controlling the growth of conjunctival bacterial flora. Use of moxifloxacin in combination with 5% povidone iodine resulted in a synergistic effect.

RESUMO Objetivo: Comparar os efeitos de iodopovidona tópico a 5% com azitromicina e moxifloxacina profiláticas sobre a flora bacteriana em pacientes submetidos à injeção intravítrea. Métodos: Um total de 132 pacientes foram aleatoriamente designados para receber tratamento com azitromicina ou moxifloxacina ou nenhum tratamento (grupo controle). No total, 528 amostras foram obtidas no momento na admissão, 4 dias antes da injeção intravítrea, 4 dias após a injeção intravítrea e 8 dias após a injeção intravítrea. As amostras foram imediatamente enviadas para o laboratório de microbiologia para incubação. Resultados: O microorganismo mais frequentemente observado foi o Staphylococcus coagulase-negativo (23,8%). Quando os resultados das amostras obtidas no dia 4 antes da injeção foram avaliados, o crescimento do Staphylococcus coagulase-negativo foi significativamente menor no grupo mo xifloxacina, em comparação com os controles (p=0,049). Acinetobacter baumannii continuou a crescer após a administração de azitromicina (p=0,033). Quando os resultados de 4 dias após a injeção intravítrea foram avaliados, o crescimento do Staphylococcus coagulase-negativo foi maior no controle, em comparação com pacientes que receberam azitromicina ou moxifloxacina (p=0,004). A taxa de erradicação também foi significativamente maior no grupo moxifloxacina do que no grupo controle (p=0,001). As amostras obtidas no dia 8 após injeção intravítrea mostraram níveis semelhantes de crescimento bacteriano em todos os grupos (p=0,217). Conclusão: A moxifloxacina foi mais eficaz do que 5% de iodopovidona no controle do crescimento da flora bacteriana conjuntival. O uso de moxifloxacina em combinação com 5% de iodopovidona resultou em um efeito sinérgico.

Diversity of metallo-b-lactamase-encoding genes found in distinct species of Acinetobacter isolated from the Brazilian Amazon Region

BACKGROUND The multidrug resistance (MDR) phenotype is frequently observed in Acinetobacter baumannii, the most clinically relevant pathogenic species of its genus; recently, other species belonging to the A. calcoaceticus-A. baumannii complex have emerged as important MDR nosocomial pathogens. OBJECTIVES The present study aimed to verify the occurrence of metallo-β-lactamase genes among distinct Acinetobacter species in a hospital located in the Brazilian Amazon Region. METHODS Antimicrobial susceptibility profiles were determined by broth microdilution. The genetic relationships among these isolates were assessed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Pyrosequencing reads of plasmids carrying the bla NDM-1 gene were generated using the Ion Torrent™ platform sequencing. FINDINGS A total of six isolates carried bla NDM-1: A. baumannii (n = 2), A. nosocomialis (n = 3), and A. pittii (n = 1); three carried bla IMP-1: A. baumannii, A. nosocomialis, and A. bereziniae. Resistance to colistin was observed for an NDM-1-producing A. nosocomialis isolate. Diverse PFGE patterns and sequence types were found among A. nosocomialis and A. baumannii isolates. The bla NDM-1 sequence was inserted in a Tn125 transposon, while the bla IMP-1 was found as a gene cassette of the class 1 integron In86. MAIN CONCLUSIONS To the best of our knowledge, this is the first report describing the dissemination of bla NDM-1 among distinct Acinetobacter species recovered from the same hospital in South America.

Earliest identification of New Delhi metallo-ß-lactamase 1 (NDM-1) in Acinetobacter pittii in Brazil

Abstract We report the occurrence in Brazil of the bla NDM-1 gene in Acinetobacter pittii, prior to the previously described first reports regarding the species Providencia rettgeri and Enterobacter hormaechei. Clinical isolates were investigated by polymerase chain reaction followed by bidirectional sequencing, and species was confirmed by 16S rDNA sequencing and matrix-assisted laser desorption-ionization time-of-flight spectrometry. A. pittii carrying bla NDM-1 was confirmed in a patient with no national or international travel history, or transfer from another hospital. The findings warn of the possibility of silent spread of bla NDM-1 to the community.

Draft genome sequence of a multidrug-resistant beta-lactamase OXA-357-producing Acinetobacter pittii ST865 clinical isolate from China

Abstract Worldwide increasing emergence of carbapenem-resistant Acinetobacter spp. has rendered the limited availability of effective antimicrobial agents and has become a major public health concern. In this study, we report the draft genome sequence of A. pittii TCM156, a multidrug-resistant isolate that harbored the blaOXA-357 gene. The genome sequence was further analyzed by various bioinformatics methods. The genome size was estimated to be 3,807,313 bp with 3508 predicted coding regions and G + C content is 38.7%. These findings have raised awareness of the possible emergence of OXA-type enzyme-producing A. pittii isolate in China.

Draft genome sequence of phenol degrading Acinetobacter sp. Strain V2, isolated from oil contaminated soil

Abstract We report here the draft genome sequence of Acinetobacter sp. Strain V2 isolated from the oil contaminated soil collected from ENGEN, Amanzimtoti, South Africa. Degradation of phenolic compounds such as phenol, toluene, aniline etc. at 400 ppm in 24 h and oil degrading capability makes this organism an efficient multifunctional bioremediator. Genome sequencing of Acinetobacter spp. V2 was carried out on Illumina HiSeq 2000 platform (performed by the Beijing Genomics Institute [BGI], Shenzhen, China). The data obtained revealed 643 contigs with genome size of 4.0 Mb and G + C content of 38.59%.

Emergence of colistin resistance in the largest university hospital complex of São Paulo, Brazil, over five years

Abstract Colistin resistance involving Gram-negative bacilli infections is a challenge for health institutions around of the world. Carbapenem-resistance among these isolates makes colistin the last therapeutic option for this treatment. Colistin resistance among Enterobacteriaceae, Acinetobacter spp., and Pseudomonas spp. was evaluated between 2010 and 2014 years, at Hospital das Clínicas, São Paulo, Brazil. Over five years 1346 (4.0%) colistin resistant Gram-negative bacilli were evaluated. Enterobacteriaceae was the most frequent (86.1%) pathogen isolated, followed by Acinetobacter spp. (7.6%), and Pseudomonas spp. (6.3%). By temporal analysis there was a trend for an increase of colistin resistance among Enterobacteriaceae, but not among non-fermentative isolates. Among 1346 colistin resistant isolates, carbapenem susceptibility was observed in 21.5%. Colistin resistance in our hospital has been alarmingly increased among Klebsiella pneumoniae isolates in both KPC positive and negative, thus becoming a therapeutic problem.

Initial pH of medium affects organic acids production but do not affect phosphate solubilization

The pH of the culture medium directly influences the growth of microorganisms and the chemical processes that they perform. The aim of this study was to assess the influence of the initial pH of the culture medium on the production of 11 low-molecular-weight organic acids and on the solubilization of calcium phosphate by bacteria in growth medium (NBRIP). The following strains isolated from cowpea nodules were studied: UFLA03-08 (Rhizobium tropici), UFLA03-09 (Acinetobacter sp.), UFLA03-10 (Paenibacillus kribbensis), UFLA03-106 (Paenibacillus kribbensis) and UFLA03-116 (Paenibacillus sp.). The strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 solubilized Ca3(PO4)2 in liquid medium regardless of the initial pH, although without a significant difference between the treatments. The production of organic acids by these strains was assessed for all of the initial pH values investigated, and differences between the treatments were observed. Strains UFLA03-09 and UFLA03-10 produced the same acids at different initial pH values in the culture medium. There was no correlation between phosphorus solubilized from Ca3(PO4)2 in NBRIP liquid medium and the concentration of total organic acids at the different initial pH values. Therefore, the initial pH of the culture medium influences the production of organic acids by the strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 but it does not affect calcium phosphate solubilization.

Infecciones por los géneros Klebsiella y Acinetobacter en hospitales pediátricos cubanos y resistencia antibiótica / Infections caused by Klebsiella y Acinetobacter genuses in Cuban pediatric hospitals and antimicrobial resistance

Introducción: Klebsiella pneumoniae y el complejo Acinetobacter baumannii-calcoaceticus constituyen importantes patógenos nosocomiales a nivel mundial siendo más susceptibles los pacientes ingresados en neonatología y unidades de cuidados intensivos. Objetivos: caracterizar, desde el punto de vista clínico-microbiológico los aislamientos de los géneros Klebsiella y Acinetobacter causantes de infecciones en hospitales pediátricos cubanos. Métodos: se realizó un estudio descriptivo-longitudinal durante el período de Junio 2011-Septiembre 2012 que incluyó 152 aislamientos clínicos (102 de Klebsiella spp. y 50 de Acinetobacter spp) causantes de infecciones nosocomiales en niños y que fueron remitidos al Laboratorio Nacional de Referencia de Microbiología del Instituto Pedro Kourí. La identificación de esta especie se realizó mediante pruebas bioquímicas. Se determinó la susceptibilidad a 18 antimicrobianos, la producción de ß;-lactamasas de espectro extendido (BLEE) y la de metalo-ß;-lactamasas (MBLs) según las normas del Instituto de Estandarización de Laboratorio Clínico (CLSI, por sus siglas en inglés). Resultados: las muestras más frecuentes de recuperación de Acinetobacter y Klebsiella fueron sangre, secreción endotraqueal y lesiones de piel. Klebsiella pneumoniae (96 por ciento) y el complejo Acinetobacter baumannii-calcoaceticus (90 por ciento) fueron las especies más prevalentes y se aislaron con mayor frecuencia en servicios de terapias, neonatología y quemado. Ambos patógenos mostraron elevada resistencia a las cefalosporinas con 57 por ciento de producción de BLEE para el género Klebsiella spp. La resistencia a carbapenémicos solo se detectó en Acinetobacter spp (61 por ciento) mediada por la producción de metalo-&-lactamasas en un 2 por ciento de los aislamientos. La mayor susceptibilidad de este género se encontró para las tetraciclinas, mientras que el género Klebsiella spp. fue más susceptible a la ciprofloxacina. En ambos se observó resistencia elevada para los aminoglucósidos (66 por ciento-75 por ciento) y el trimetoprim-sulfametoxazol (45 por ciento-60 por ciento). Conclusiones: Klebsiella pneumoniae y el Complejo Acinetobacter baumannii-calcoaceticus constituyen un peligro potencial en servicios pediátricos con escasas opciones terapéuticas quedando como únicas alternativas los carbapenémicos para las infecciones por Klebsiella spp multidrogorresistentes y la colistina para las infecciones por Acinetobacter spp con extrema drogorresistencia(AU)

Introduction: Klebsiella pneumoniae and the Acinetobacter baumannii-calcoaceticus complex represent important nosocomial pathogens worldwide. The patients admitted to the neonatology and the intensive care unit services suffer infections very frequently. Objectives: to characterize clinically and microbiologically Klebsiella and Acinetobacter isolates causing infections in Cuban pediatric hospitals. Methods: a descriptive longitudinal study of 152 clinical isolates (102 Klebsiella spp and 50 Acinetobacter spp), which caused nosocomial infections in children and were sent to the national reference laboratory of microbiology in Pedro Kouri Institute. The study was conducted from June 2011 to September 2012. The species were identified by biochemical tests. The susceptibility to 18 antimicrobials, the production of extended spectrum ß-lactamase (ESBL) and metallo-ß-lactamases were determined according to the Clinical and Laboratory Standards Institute. Results: the most frequent infections in infants and children by Acinetobacter and Klebsiella were found in blood, endotracheal secretion and skin lesions.. Klebsiella pneumoniae (96 percent) and Acinetobacter baumannii-calcoaceticus complexes (90 percent) were the most prevalent species and were frequently isolated in intensive care, neonatology and burned patient wards. Both pathogens showed high resistance to cephalosporins with 57 percent of extended-spectrum betalactamase production in Klebsiella spp. Resistance to carbapenems was only detected in Acinetobacter (61 percent) with 2 percent of metallobetalactamse production. Acinetobacter spp. was more susceptible to tetracyclines and cholistin where Klebsiella spp was more susceptible to ciprofloxacin. In both pathogens, a high resistance to aminoglycosides (66 percent -75 percent) and trimethoprim-sulfamethoxazole (45 percent-60 percent) was observed. Conclusions: Klebsiella pneumoniae and Acinetobacter baumannii-calcoaceticus complex represent a potential threat in pediatric services with few therapeutic options. The carbapenems remain the only alternative to severe infections caused by multidrug resistant Klebsiella spp and cholistin is the only choice to treat extreme multidrug resistant Acinetobacter spp infections(AU)