Current Microbiology

Dhole, Archana; Shelat, Harsha

doi: 10.1007/s00284-022-02792-xpmid: 35157135

Root nodules of legume plants are devoted for hosting endophytic symbiotic bacteria that fix atmospheric nitrogen but recently proved as a niche for various non-rhizobial endophytes (NRE) also. In the present investigation, one rhizobial and two NRE were isolated and characterized as Rhizobium sp. AAU B3, Bacillus sp. AAU B6 and Bacillus sp. AAU B12. These isolates were studied for in vitro biocontrol activity against two pathogenic fungi. NRE isolates exhibited antifungal activity against root rot causing Macrophomina phaseolina (ITCC-6749) isolated from Vigna radiata and wilt causing pathogen Fusarium udum Butler isolated from Cajanus cajan in liquid as well as on solid medium. Furthermore, their antagonism was increased markedly when combined with Rhizobium sp. Moreover, Bacillus sp. AAU B6 showed amplification of the zwittermicin A gene (~ 950 bp) which is evident for the production of antibiotics. All three isolates showed HCN production in vitro also, Bacillus sp. AAU B12 exhibited amplification of its gene hcnC. Pathogenic fungal hyphae became thin, transparent, and bent as well as fungi lost their normal growth and branching patterns when exposed to volatile compounds produced by NRE. All the 3 isolates produced siderophores, however siderophore production was increased considerably when all three strains are mixed together. Furthermore, all the three isolates produced cell wall degrading enzymes (chitinase, protease, and cellulase) but lipolytic activity was exhibited only by Rhizobium sp. AAU B3. When NRE inoculated in combination of Rhizobium; overcomes the disease severity against M. phaseolina under pot study. Thus, from present study it is concluded that co-inoculation of NRE and Rhizobium sp. can be exploited as biocontrol bio-agents against M. phaseolina in green gram at field levels.

Yousefi, Zahra; Taheri, Niloofar; Dargahi, Motahareh; Chaman, Reza; Binesh, Ehsan; Emamian, Mohammad Hassan; Jafari, Reza

doi: 10.1007/s00284-022-02800-0pmid: 35150319

Antibodies against severe acute respiratory syndrome coronavirus-2 (Anti-SARS-COV-2) can be detected in patients with COVID-19 in 7 to 10 days post onset of symptoms (POS). However, there is no firm evidence of the long-term persistence of these antibodies in recovered COVID-19 patients. Therefore, this study aimed to evaluate the stability of anti-SARS-COV-2 IgG in recovered COVID-19 patients in a 15-month follow-up testing. Thirty hospitalized patients with real-time PCR-confirmed SARS-COV-2 infections were included in the study and five serum samples (1st, 2nd, 3rd, 4th, and 5th) were collected from each participant. The serum levels of N and S specific anti-SARS-COV-2 IgG and IgM antibodies were evaluated by the immunoassay technique at the same time. To determine the correlation between levels of anti-SARS-CoV-2 IgG/IgM with severity of disease, neutrophil-to-lymphocyte ratio (NLR %), and the serum levels of C-reactive protein were evaluated using an automated analyzer and turbidimetry assays, respectively. The mean serum level of anti-SARS-CoV-2 IgG antibody was at the highest level up to 90 days and then decreased significantly 1 year POS (P < 0.0001). However, it was still detectable in a 15-month follow-up testing. There were no significant differences in the mean levels of IgG antibody in patients with mild, moderate, and severe diseases. The results from this study suggest that the titer of anti-SARS-COV-2 IgG antibody is detectable at high levels up to 3 months and then decreases over time. However, these antibodies can be reliably detected in up to 15 months, and they may persist for a long time.

Huang, Zhaobin; Huang, Yuanyuan; Lai, Qiliang; Chen, Xinlan; Dong, Chunming; Huang, Xiaozhou

doi: 10.1007/s00284-022-02798-5pmid: 35150341

A Gram-stain-negative, rod-shaped, motile, mesophilic, and aerobic bacterial strain, designated SM2-42 T was isolated from a mangrove sediment. Catalase activity and oxidase activity were positive. Growth was observed at 20 °C–40 °C, pH 6.0–8.0, and in the presence of 0.5–5.0% NaCl. Cells of strain SM2-42 T contained poly-β-hydroxybutyrate granules. The 16S rRNA gene of strain SM2-42 T had maximum sequence similarity with Oceanobacter kriegii 197 T of 97.1%. Phylogenetic analysis based on 16S rRNA gene sequence and 120 conserved concatenated proteins indicated that strain SM2-42 T was affiliated to the genus Oceanobacter and formed a monophyletic branch with O. kriegii 197 T. The average nucleotide identity and digital DNA-DNA hybridization values between strain SM2-42 T and O. kriegii 197 T were 76.43% and 21.60%, respectively. The major isoprenoid quinone was Q-8. The major fatty acids (> 10%) comprised C16:0, summed feature 8 (C18:1ω7c and C18:1ω6c), C18:0, and summed feature 3 (C16:1ω7c and/or C16:1ω6c). The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminolipid and two unidentified lipids. The draft genome size was 5,115,008 bp with DNA G + C content of 54.3%. Based on phylogenetic analyses and whole genomic comparisons, strain SM2-42 T represented a novel species, for which the name Oceanobacter mangrovi sp. nov. was proposed. The type strain was SM2-42 T (= MCCC 1K06300T = KCTC 82938 T).

Shen, Lei; Liu, Pengxiao; An, Miaomiao; Liang, Ruina; He, Xiangwei; Zhao, Guozhu

doi: 10.1007/s00284-022-02819-3pmid: 35239058

Strain XMGL2T, isolated from rhizosphere soil of Quercus mongolica in China, was characterized using a polyphasic taxonomic approach. Cells were Gram-negative, aerobic, non-spore-forming, and rod-shaped. Growth occurred at 20–37 °C (optimum, 28 °C), pH 5.0–10.0 (optimum, pH 6.0), and with 0–1% NaCl (optimum, 1%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain XMGL2T was related to members of the genus Sphingomonas and had the highest 16S rRNA gene sequence identity to Sphingomonas oleivorans FW-11 T (96.4%). The average nucleotide identity and digital DNA–DNA hybridization values between strain XMGL2T and the closely related taxa Sphingomonas oleivorans FW-11 T and Sphingomonas fennica K101T were 75.3/19.8% and 75.8/20.2%, respectively. The major cellular fatty acids were C18:1ω7c, C14:0 2-OH, and C16:0. The major isoprenoid quinone was Q-10 and the polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine, an unidentified glycophospholipid and an unidentified phospholipid. The genomic DNA G + C content was 67.9%. Based on the phenotypic and genotypic properties and phylogenetic inference, strain XMGL2T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas quercus sp. nov. is proposed. The type strain is XMGL2T (= JCM 34441 T = GDMCC 1.2153 T).

Zhao, Huilin; Tian, Yue; Sun, Xunke; Wu, Qianwen; Chen, Si; Shan, Jiangfan; Zhong, Yu; Chen, Xinyu; Gao, Xiaoxue; Liu, Shengnan; Wang, Ruochen; Du, Zongjun; Li, Boqing; Ji, Xiaofei

Hedayati, Manouchehr Ahmadi; Khani, Delniya; Sheikhesmaeili, Farshad

doi: 10.1007/s00284-022-02775-ypmid: 35195783

Sirtuins, known as the intracellular acylation enzymes, play a major role in regulating the cell's physiological activities. The relevant studies have shown diversely sirtuin genes expression in various cancers in humans. This study has surveyed the transcription of sirt3, 6, and 7 genes in gastric antral epithelial cells (GAECs) of gastritis and gastric adenocarcinoma patients with and without Helicobacter pylori infection. First of all, a case–control study was conducted, including 50 and 53 gastric antral biopsy samples collected from gastritis and gastric adenocarcinoma patients with and without H. pylori infection referred to hospitals of Sanandaj City during 2018–2019. Total RNAs were extracted from biopsy samples, then cDNAs were synthesized by using TaKaRa kits. Quality essay of H. pylori virulence genes expression and relative quantitative essay of sirt3, 6, and 7 genes expressions in gastric antral biopsy samples were performed using the real-time RT-PCR method. The statistical analysis showed the significant correlations between H. pylori vacA s1m2 and sabA cDNAs with sirt3 geneś expression in GAECs (P < 0.05, 0.05 respectively). In addition, sirt6 gene's expression decreased along increasing age in gastric adenocarcinoma patients (P < 0.05). The samples of gastritis patients with gastric antral epithelial biopsy containing H. pylori hopQII, oipA, and sabB cDNA showed an increased amount of sirt7 genes expression (P < 0.05, 0.05, and 0.05 respectively). In conclusion, the H. pylori virulence genes expression and increasing age of patients showed the significant correlations with sirt3, 6, and 7 genes expressions in GAECs of gastric and gastric cancer patients.

Nisa, Iqbal; Haroon, Mohammad; Driessen, Arnold; Nijland, Jeroen; Rahman, Hazir; Yasin, Nusrat; Hussain, Mubashir; Khan, Taj Ali; Ali, Amjad; Khan, Saeed Ahmad; Qasim, Muhammad

doi: 10.1007/s00284-022-02805-9

Abdullah, Sayed; Ain, Quratul; Jalil, Amna; Khan, Dilawar; Khan, Arsalan; Qasim, Muhammad; Badshah, Malik; Adnan, Fazal

doi: 10.1007/s00284-022-02791-ypmid: 35157141

Curli fimbriae, a virulent factor of the Avian Pathogenic Escherichia coli (APEC), is responsible for adhesion, biofilm formation, and colonization of pathogen. Major curli fimbriae protein is encoded by csgA gene. APEC is one of the leading causes of colibacillosis in poultry flocks and due to excessive use of antibiotics and vaccines in poultry, the emergence of various multi-drug resistant (MDR) bacterial strainsare is frequently reported. The growing concern of MDR bacterial strains necessitate novel antibacterial approaches to combat colibacillosis in poultry. RNA-based gene silencing is a very specific and robust strategy to target specific bacterial factors involved in pathogenicity and virulence. In this study, a phagemid-mediated sRNA expression system to target a vital gene, csgA, is employed. This comprises an M13 phagemid harboring a sRNA expression cassette and a pre-designed GUIDE sequences for the csgA target gene. To target the csgA gene at the mRNA level, a GUIDE sequence was computationally designed for pre-designed sRNA expression cassette. Online web tools were used to predict the binding energy, secondary structure, and off-target binding potential of the sRNA to optimize its expression. Results showed that the designed sRNA has a binding energy of − 29.60 kcal/mol with zero off-targets. After expression of the sRNA in the APEC cells, ̴ 45% reduction in the csgA level was observed via RT-PCR in the CS-APEC-O1 strains compared to the wt-APEC-O1. Similarly, the biofilm forming ability decreased by 40% in the CS-APEC-O1 strains. The swarming motility and hemagglutination efficiency were not affected by the sRNA expression. Future studies investigating the in vivo efficiency of M13 phagemid delivery are required to evaluate its candidacy in phage therapy.

Kobayashi, Fumiyuki; Odake, Sachiko

doi: 10.1007/s00284-022-02817-5pmid: 35235071

To clarify the lethal injury related to the inactivation of Saccharomyces pastorianus cells by low-pressure carbon dioxide microbubble (CO2MB) treatment, surviving number, leakage of nucleic acids and proteins, fluorescence polarisation (FP) of the cell membrane, activity of alkaline phosphatase (AP), intracellular pH (pHin), mitochondrial membrane potential (MMP), cell surface hydrophobicity (CSH) and oxidative stress of S. pastorianus treated with CO2MB at various temperatures were measured. The number of surviving S. pastorianus cells decreased below the detection limit after CO2MB treatment at temperatures of 40, 45 and 50 ℃, inducing a 2-log reduction at 35 ℃. The S. pastorianus cells treated with CO2MB at temperatures above 40 ℃ showed an increase in FP and leakage of nucleic acids and proteins. The AP in S. pastorianus cells treated with CO2MB at a temperature of 35 ℃ was also activated but inactivated at temperatures above 40 ℃. Furthermore, the decrease in pHin and MMP and the increase in CSH of S. pastorianus were caused by CO2MB treatment at temperatures above 35 ℃. Oxidative stress in S. pastorianus cells was also increased by CO2MB treatment without warming but decreased at temperatures above 35 ℃. Our results lead us to infer that the type of cell injury in S. pastorianus induced by CO2MB treatment differed from that caused by the treatment temperature and that the lethal injury was enzyme inactivation.

Mapipa, Qaqamba; Digban, Tennison Onoriode; Nnolim, Nonso Emmanuel; Nontongana, Nolonwabo; Okoh, Anthony Ifeanyi; Nwodo, Uchechukwu U.

doi: 10.1007/s00284-022-02815-7pmid: 35258680

Acinetobacter baumannii (A. baumannii) plays a significant part in nosocomial infections world over and is re-emerging as a formidable pathogen due to the wide range of antibiotic resistance factors it acquires and environmental resilience. The high attendance of patients (outpatients and inpatients) into the health care facilities formed the basis for the selection of the hospitals. Consequently, this study profiled the antibiogram and antibiotic resistance genes of A. baumannii isolated from selected hospital wastewater effluents. A total of twenty-four (24) wastewater samples from three selected hospital drainages were collected and analysed presumptively by culture-dependent methods for A. baumannii. The identity confirmation of A. baumannii was done by the amplification of recA and blaoxa-51 genes. Virulence and antibiotic resistance markers were assessed using polymerase chain reaction. A total of 53 A. baumannii isolates were confirmed and the highest antibiotic resistance profile was 93% (piperacillin). Multiple antibiotic resistance index (MARI) showed a range of 0.23 and 0.46. FimH virulence gene was detected in 29 (55%) of the isolates. Tetracycline and beta-lactam resistance markers were found; 70% and 92% of the isolates possessed tetA and ampC genes. The isolates showed high level of resistance to antibiotics. The multiple antibiotic resistance index (MARI) of ≥ 0.2 indicates that some of the isolates harbour virulence and resistance traits emerging from high-risk source thereby projecting a threat to public health.