Abstract A laboratory experiment was conducted to isolate and diagnose bacterial isolates from Pseudomonas aeruginosa and test their efficiency in dissolving tri-calcium phosphate in solid cultures. ...10 samples were collected from the soil and rhizosphere of different crops such as (coffee, barley, radishes, alfalfa) for several geographical regions, namely Thi-Qar, Muthanna, Qadisiyah and Najaf. Serial decimal dilutions of soil samples were carried out in order to isolate the bacteria, as King B medium was used to isolate the bacteria. The results showed obtaining bacterial isolates belonging to the bacteria Pseudomonas aeruginosa , which were diagnosed based on phenotypic traits and biochemical tests and by using special keys for diagnosis. With isolates P2, P10, and P1, the values were 2.46, 2.41, and 2.33, respectively, and the lowest values were represented by isolate 3P, which amounted to 21.4. The values of the other isolates varied in their phosphate solubility values, and the results indicated that there were no significant differences between P2 and P10.
The isolation and identification of secondary wound infection bacteria in diabetic patients in Jambi City are crucial for developing effective treatment strategies. The diversity of infecting ...bacteria underscores the importance of discerning the most prevalent types. This research aims to identify bacteria causing secondary wound infections in diabetic patients. Researchers obtained samples for this descriptive cross-sectional study by swabbing the incisions of diabetic patients at RSUD H. Abdul Manap in Jambi City between August and October 2023. Gram staining, culturing, and enzymatic tests were performed on the samples. Out of 21 samples, the age group most affected was 45-59 years (61.9%), predominantly male (81%), engaged in high-risk occupations (42.9%), with lower extremity wounds (90.5%), and primary wounds diagnosed as vulnus scissum and vulnus abrasio (33.3%). In contrast, DM ulcers constituted 66.7% of secondary wound infections in diabetic patients. Bacterial identification revealed Staphylococcus aureus as the predominant species (42.9%) responsible for secondary wound infections in diabetic patients. This study underscores the dominance of Staphylococcus aureus in secondary wound infections among diabetic patients.
Species of the bacterial genus
live in a symbiotic relationship with
entomopathogenic nematodes. Besides their use as biological control agents against agricultural pests, some
species are also a ...source of natural products and are of medical interest due to their ability to cause tissue infections and subcutaneous lesions in humans. Given the diversity of
species, rapid and reliable methods to resolve this genus to the species level are needed. In this study, we evaluated the potential of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the identification of
species. To this end, we established a collection of 54 isolates consisting of type strains and multiple field strains that belong to each of the validly described species and subspecies of this genus. Reference spectra for the strains were generated and used to complement a currently available database. The extended reference database was then used for identification based on the direct transfer sample preparation method and the protein fingerprint of single colonies. High-level discrimination of distantly related species was observed. However, lower discrimination was observed with some of the most closely related species and subspecies. Our results therefore suggest that MALDI-TOF MS can be used to correctly identify
strains at the genus and species level, but has limited resolution power for closely related species and subspecies. Our study demonstrates the suitability and limitations of MALDI-TOF-based identification methods for assessment of the taxonomic position and identification of
isolates.
Matrix-assisted laser desorption ionization-time of flight mass spectrometry is not widely used to identify bacteria directly from positive blood culture bottles (BCBs) because of overlong protocols. ...The objective of this work was to develop and evaluate a simple extraction protocol for reliable identification from BCBs. The 10-min protocol was applied over a 5-month period. Direct identifications on day 0 were compared with those obtained from colonies on day 1 log(score) of ≥2. We evaluated a range of seven log(score) thresholds on day 0 from 1.4 to 2.0 to find the lower confidence score that provides the higher percentage of direct identifications without loss of accuracy. With a log(score) threshold of ≥1.5 at day 0, our protocol allowed us to identify 80% of bacteria in 632 BCBs (96% of
, 95% of
, 92% of enterococci, and 62% of streptococci). At least one bacterial species of the mixture was identified in 77% of the polymicrobial samples. The rapidity and reliability of the protocol were factors in its adoption for routine use, allowing us to save up to 24 h in identifying 80% of the bacteria in the BCBs and, thus, to supply useful information to adapt antibiotic therapy when necessary. We currently provide reliable daily direct identifications of staphylococci, enterococci,
,
and beta-hemolytic streptococci.
The effect evaluation of the antibiotic susceptibility test based on bacterial solution is of great significance for clinical diagnosis and prevention of antibiotic abuse. Applying a microfluidic ...chip as the detection platform, the detection method of using microscopic images to observe bacteria under antibiotic can greatly speed up the detection time, which is more suitable for high-throughput detection. However, due to the influence of the depth of the microchannel, there are multiple layers of bacteria under the focal depth of the microscope, which greatly affects the counting and recognition accuracy and increases the difficulty of relocation of the target bacteria, as well as extracting the characteristics of bacterial liquid changes under the action of antibiotics. After the focal depth of the target bacteria is determined, although the z-axis can be controlled with the help of a three-dimensional micro-operator, the equipment is difficult to operate and the long-term changes of the target bacteria cannot be tracked quickly and accurately. In this paper, the YOLOv5 algorithm is adopted to accurately identify bacteria with different focusing states of multi-layer bacteria at the z-axis with any focal depth. In the meantime, a certain amount of microspheres were mixed into bacteria to assist in locating bacteria, which was convenient for tracking the growth state of bacteria over a long period, and the recognition rates of both bacteria and microspheres were high. The recognition accuracy and counting accuracy of bacteria are 0.734 and 0.714, and the two recognition rates of microspheres are 0.910 and 0.927, respectively, which are much higher than the counting accuracy of 0.142 for bacteria and 0.781 for microspheres with the method of enhanced depth of field (EDF method). Moreover, during long-term bacterial tracking and detection, target bacteria at multiple z-axis focal depth positions can be recorded by the aid of microspheres as a positioning aid for 3D reconstruction, and the focal depth positions can be repositioned within 3–10 h. The structural similarity (SSIM) of microscopic image structure differences at the same focal depth fluctuates between 0.960 and 0.975 at different times, and the root-mean-square error (RMSE) fluctuates between 8 and 12, which indicates that the method also has good relocation accuracy. Thus, this method provides the basis for rapid, high-throughput, and long-term analysis of microscopic changes (e.g., morphology, size) of bacteria detection under the addition of antibiotics with different concentrations based on microfluidic channels in the future.
This review discusses the relationship of the efflux pump (EP) system of Gram-negative bacteria to other antibiotic resistance mechanisms of the bacterium such as quorum sensing, biofilms, two ...component regulons, etc. The genetic responses of a Gram-negative to an antibiotic that render it immune to an antibiotic are also discussed. Lastly, the methods that have been developed for the identification of bacteria that over-express their EP system are presented in detail. Phenothiazines are well-known antipsychotic drugs with reported activity against bacterial EPs and other ancillary antibiotic mechanisms of the organism. Therefore these compounds will also be discussed.
Aims
Tattooing and use of permanent makeup (PMU) has dramatically increased over the last decade, with a concomitant increase in ink‐related infections. The aim of this study was to determine whether ...micro‐organisms are present, and if so, the number and their identification in the commercial tattoo and PMU inks available in the United States.
Methods and Results
We surveyed 85 unopened tattoo and PMU inks, purchased from 13 companies. We incubated 100 μl of ink samples on trypticase soy agar plates for bacterial growth, 7H10 Middlebrook medium for mycobacterial growth, and Sabouraud dextrose medium for fungal growth. In total, 42 inks were contaminated with micro‐organisms (49%). Thirty‐three inks were contaminated with bacteria, 2 inks with fungi, and 7 inks had both bacterial and fungal growth. Mycobacteria were not detected in any of the examined tattoo and PMU inks. In 26 inks, microbial concentrations ranged between 101 and 103 CFU per ml, but higher counts (>103 CFU per ml) were recorded in 16 inks. We identified 83 bacteria by their 16S rDNA sequences, including 20 genera and 49 species. Strains of Bacillus spp. (53%) were dominant, followed by Lysinibacillus fusiformis (7%) and Pseudomonas aeruginosa (5%). Thirty‐four (41%) possibly clinically relevant strains were identified, including P. aeruginosa, Dermacoccus barathri and Roseomonas mucosa, some of which have been previously reported to be associated with human skin infections.
Conclusions
The results indicate that commercial tattoo and PMU inks on the US market surveyed in this study contain a wide range of micro‐organisms, including pathogenic bacteria.
Significance and Impact of the Study
Microbial contaminants in tattoo and PMU inks are an emerging safety concern for public health. This study provides evidence that microbial contamination of tattoo and PMU inks available in the United States is more common than previously thought and highlights the importance of monitoring these products for potentially pathogenic micro‐organisms.
•Two out of eight isolates obtained from cattle milk and feces showed characteristics of propionibacteria.•Probe Pap446 identified two isolates as Acidipropionibacterium acidipropionici.•The identity ...of these isolates was confirmed by molecular techniques.
Acidipropionibacterium acidipropionici is widely used for many applications, such as propionic acid production, cereal silage, and also as probiotic. Due to this plethora of applications, new isolates of A. acidipropionici with improved features are being searched for. These new isolates must be accurately identified, however, most approaches become expensive and time-consuming when the number of isolates is high. On the contrary, fluorescence in situ hybridization allows the affordable, reliable, and rapid identification of microorganisms in pure cultures and environmental and medical samples. Therefore, the aim of this work was to apply a fluorescent in situ hybridization probe for the reliable identification of new A. acidipropionici isolates. To this end, probe Pap446, specific for A. acidipropionici, was validated by hybridization assays with strains of this species from different origins, other species of the same genus or family, and unrelated genera. Eight isolates with propionibacterium characteristics were obtained from milk and feces of cows. Probe Pap446, hybridized only with isolates III and VI. The identity of these isolates was further confirmed by PCR using group and species-specific primers for propionibacteria and 16S rDNA sequencing.
Acidipropionibacterium acidipropionici es ampliamente usada para diversas aplicaciones, como producción de ácido propiónico, ensilado de cereales y probiótico. Debido a esta variedad de aplicaciones, continuamente se buscan nuevos aislamientos de A. acidipropionici con características nuevas. Estos nuevos aislamientos deben ser identificados correctamente, pero la mayoría de las técnicas disponibles resultan costosas e insumen mucho tiempo cuando el número de aislamientos es elevado. Por el contrario, la hibridación fluorescente in situ permite una identificación barata, confiable
y rápida de microorganismos en cultivos puros y en muestras ambientales y médicas. Por lo tanto, el objetivo de este trabajo fue la aplicación de una sonda oligonucleotídica en un protocolo de hibridación fluorescente in situ para la identificación confiable de nuevos aislamientos de A. acidipropionici. Con este fin, se validó la sonda Pap446, específica de A. acidipropionici mediante ensayos de hibridación con cepas de esta especie de diferente origen, otras especies del mismo género o familia, y géneros no relacionados. Se obtuvieron ocho aislamientos con características de propionibacterias a partir de leche y heces de vacas. La sonda Pap446, hibridó únicamente con los aislamientos III y VI. La identidad de estos aislamientos fue confirmada a través de PCR con cebadores específicos para propionibacterias y para A. acidipropionici, y mediante secuenciación del ADNr 16S.
In order to explore the possibility to identify common wound infection bacteria in mixed culture with gas chromatograph-ion migration spectroscopy (GC-IMS), the headspace gas of single and mixed ...cultures of
Escherichia coli
,
Staphylococcus aureus
and
Pseudomonas aeruginosa
were detected and analyzed by GC-IMS system. The bacteria were cultured in thioglycolate medium tubes then transferred to the sampling bottles (indirect method), or directly cultured in the sampling bottles (direct method) to allow accumulation of volatile compounds and facilitate automation. The specific microorganism volatile organic compounds (mVOCs) of the three bacteria were obtained. Some of them have been known to certain substance, for example, ethanol, isoamyl acetate, Phenylacetaldehyde, 2-heptanone etc., while others have not. Principal component analysis (PCA) showed that a higher separability can be achieved with direct method than indirect method. This work indicated that it is possible to identify compound bacteria by detecting specific mVOCs with GC-IMS, and the specific mVOCs should be medium-dependent.
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