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This study aimed to identify the primary pathogenic bacteria responsible for the mortality of the Chinese giant salamander (Andriasd davidianus). A pathogenic bacterium was isolated from a diseased Chinese giant salamander exhibiting typical symptoms under aseptic conditions and then identified by morphological examinations, biochemical analysis, and the sequence analysis of bacterial 16S rRNA. Artificial infection testing was then conducted to determine the pathogenicity of the isolated bacteria strain. Drug susceptibility tests were conducted using the agar diffusion method. The isolated pathogenic bacteria, named DN-2, was successfully identified as Acinetobacter lwoffii. The artificial infection showed that the typical symptoms of the disease could be replicated as the ones originally occurred, and this bacterium exhibited high pathogenicity to the Chinese giant salamander. In the Chinese giant salamander, the median lethal dosage (LD50) of A. lwoffii DN-2 for A. davidianus was determined to be 4.63*104 CFU/g. Drug sensitivity testing showed that these bacteria were highly sensitive to erythromycin, gentamicin, neomycin, streptomycin, midecamycin, ciprofloxacin, piperacillin, florfenicol, doxycycline, carbenicillin, and sulfanilamide. In summary, A. lwoffii was identified as the primary pathogen responsible for the demise of A. davidianus. Our study first presents how these bacteria harm Chinese giant salamanders. [ABSTRACT FROM AUTHOR]

Acinetobacter lwoffii is widely considered to be a harmful bacterium that is resistant to medicines and disinfectants. A. lwoffii NL1 degrades phenols efficiently and shows promise as an aromatic compound degrader in antibiotic-contaminated environments. To gain a comprehensive understanding of A. lwoffii, the first genome-scale metabolic model of A. lwoffii was constructed using semi-automated and manual methods. The iNX811 model, which includes 811 genes, 1071 metabolites, and 1155 reactions, was validated using 39 unique carbon and nitrogen sources. Genes and metabolites critical for cell growth were analyzed, and 12 essential metabolites (mainly in the biosynthesis and metabolism of glycan, lysine, and cofactors) were identified as antibacterial drug targets. Moreover, to explore the metabolic response to phenols, metabolic flux was simulated by integrating transcriptomics, and the significantly changed metabolism mainly included central carbon metabolism, along with some transport reactions. In addition, the addition of substances that effectively improved phenol degradation was predicted and validated using the model. Overall, the reconstruction and analysis of model iNX811 helped to study the antimicrobial systems and biodegradation behavior of A. lwoffii. [ABSTRACT FROM AUTHOR]

Dairy mastitis is one of the most common diseases in dairy farming, and the formation of pathogenic bacteria biofilms may be an important reason why traditional antibiotic therapy fails to resolve some cases of dairy mastitis. We isolated and identified three strains of A. lwoffii were with strong biofilm forming ability from dairy cow mastitis samples from Chongqing dairy farms in China. In order to investigate the effect of novel anti-biofilm peptide CRAMP-34 on A.lwoffii biofilms, the anti-biofilm effect was evaluated by crystal violet staining, biofilms viable bacteria counting and confocal laser scanning microscopy (CLSM). In addition, transcriptome sequencing analysis, qRT-PCR and phenotypic verification were used to explore the mechanism of its action. The results showed that CRAMP-34 had a dose-dependent eradicating effect on A. lwoffii biofilms. Transcriptome sequencing analysis showed that 36 differentially expressed genes (11 up-regulated and 25 down-regulated) were detected after the intervention with the sub-inhibitory concentration of CRAMP-34. These differentially expressed genes may be related to enzyme synthesis, fimbriae, iron uptake system, capsular polysaccharide and other virulence factors through the functional analysis of differential genes. The results of subsequent bacterial motility and adhesion tests showed that the motility of A.lwoffii were enhanced after the intervention of CRAMP-34, but there was no significant change in adhesion. It was speculated that CRAMP-34 may promote the dispersion of biofilm bacteria by enhancing the motility of biofilm bacteria, thereby achieving the effect of eradicating biofilms. Therefore, these results, along with our other previous findings, suggest that CRAMP-34 holds promise as a new biofilm eradicator and deserves further research and development. [ABSTRACT FROM AUTHOR]

为了筛选高产脂肪酶菌株并探究其对高含油废水的降解能力，采用传统的微生物筛选法从餐厨废水中分离筛选菌株，考察菌株对高含油废水（油脂含量20 g/L）的油脂降解率和产脂肪酶酶活，并对产脂肪酶酶活较高的菌株进行鉴定。采用单因素实验和响应面实验对鉴定菌株发酵产脂肪酶的工艺条件进行优化。结果表明：从餐厨废水中筛选出3株细菌、2株酵母菌，其中2株细菌可在高含油废水中快速生长代谢，油脂降解率和产脂肪酶酶活均较高，经鉴定1株为解淀粉芽孢杆菌（Bi），1株为鲁氏不动杆菌（Bu）；Bi产脂肪酶最优发酵工艺条件为pH 6.69、氯化钠含量301 g/L、蛋白胨含量6.01 g/L；Bu产脂肪酶最优发酵工艺条件为pH 5.07、氯化钠含量6.10 g/L、蛋白胨含量9.38 g/L；在最优发酵工艺条件下，Bi和Bu产脂肪酶酶活分别为（222.83±0.91）U/mL和（231.50±2.28）U/mL，优化后的Bu产脂肪酶酶活甚至高于初始脂肪酶酶活更高的Bi。综上，2株细菌具有高含油废水降解能力，具备广阔的应用前景。In order to screen high lipase-producing strains and explore the ability to degrade highly oily wastewater, the traditional microbial screening method was used to select the strains from the kitchen wastewater, and the oil degradation rate of highly oily wastewater (oil content 20 g/L) and the lipase activity of the selected strains were studied. Strains with higher lipase production activity were identified. Furthermore, single factor experiment and response surface methodology were employed to optimize the fermentation conditions for lipase production of the identified strains. The results indicated that three bacterial strains and two yeast strains were screened from kitchen wastewater, two bacteria grew and metabolized rapidly in highly oily wastewater, and the oil degradation rate and lipase activity were higher, which were identified as Bacillus amyloliquefaciens （Bi）and Acinetobacter lwoffii（Bu）, respectively. The optimal fermentation conditions for lipase production by Bi were pH 6.69, NaCl content 3.01 g/L, peptone content 6.01 g/L, and lipase activity was (222.83±0.91) U/mL, while that of Bu were pH 5.07, NaCl content 6.10 g/L, peptone content 9.38 g/L, and the lipase activity was (231.50±2.28) U/mL. The lipase activity of Bu after optimization even higher than that of Bi , which had a greater initial lipase activity. In conclusion, these two bacterial strains show a high biodegradation performance for highly oily wastewater, and they have a wide application prospect.

Abstract 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.

Abstract Background Acinetobacter lwoffii (A.lwoffii) is a serious zoonotic pathogen that has been identified as a cause of infections such as meningitis, bacteremia and pneumonia. In recent years, the infection rate and detection rate of A.lwoffii is increasing, especially in the breeding industry. Due to the presence of biofilms, it is difficult to eradicate and has become a potential super drug-resistant bacteria. Therefore, eradication of preformed biofilm is an alternative therapeutic action to control A.lwoffii infection. The present study aimed to clarify that baicalin could eradicate A.lwoffii biofilm in dairy cows, and to explore the mechanism of baicalin eradicating A.lwoffii. Results The results showed that compared to the control group, the 4 MIC of baicalin significantly eradicated the preformed biofilm, and the effect was stable at this concentration, the number of viable bacteria in the biofilm was decreased by 0.67 Log10CFU/mL. The total fluorescence intensity of biofilm bacteria decreased significantly, with a reduction rate of 67.0%. There were 833 differentially expressed genes (367 up-regulated and 466 down-regulated), whose functions mainly focused on oxidative phosphorylation, biofilm regulation system and trehalose synthesis. Molecular docking analysis predicted 11 groups of target proteins that were well combined with baicalin, and the content of trehalose decreased significantly after the biofilm of A.lwoffii was treated with baicalin. Conclusions The present study evaluated the antibiofilm potential of baicalin against A.lwoffii. Baicalin revealed strong antibiofilm potential against A.lwoffii. Baicalin induced biofilm eradication may be related to oxidative phosphorylation and TCSs. Moreover, the decrease of trehalose content may be related to biofilm eradication.

Microorganism-based methods have been widely applied for the treatment of phenol-polluted environments. The previously isolated Acinetobacter lwoffii NL1 strain could completely degrade 0.5 g/L phenol within 12 h, but not higher concentrations of phenol. In this study, we developed an evolutionary strain NL115, through adaptive laboratory evolution, which possessed improved degradation ability and was able to degrade 1.5 g/L phenol within 12 h. Compared with that of the starting strain NL1, the concentration of degradable phenol by the developed strain increased three-fold; its phenol tolerance was also enhanced. Furthermore, comparative genomics showed that sense mutations mainly occurred in genes encoding alkyl hydroperoxide reductase, phenol hydroxylase, 30S ribosomal protein, and mercury resistance operon. Comparative transcriptomics between A. lwoffii NL115 and NL1 revealed the enrichment of direct degradation, stress resistance, and vital activity processes among the metabolic responses of A. lwoffii adapted to phenol stress. Among these, all the upregulated genes (log2fold-change > 5) encoded peroxidases. A phenotypic comparison of A. lwoffii NL1 and NL115 found that the adapted strain NL115 exhibited strengthened antioxidant capacity. Furthermore, the increased enzymatic activities of phenol hydroxylase and alkyl hydroperoxide reductase in A. lwoffii NL115 validated their response to phenol. Overall, this study provides insight into the mechanism of efficient phenol degradation through adaptive microbial evolution and can help to drive improvements in phenol bioremediation. [ABSTRACT FROM AUTHOR]

The incidence of Acinetobacter infections has increased in recent years. Acinetobacter infections are resistant to most antibiotics and can be found in hospitalized patients. Pregnancies complicated by severe sepsis or septic shock are associated with a higher rate of preterm labor and delivery, fetal infection, and operative delivery. This case report describes septic shock due to Acinetobacter lwoffii infection in the 31st week of gestation. A 47-year-old woman, with a gestation of 31 weeks and one day, presented with a fever, and signs of bacterial infection on laboratory tests. Although the patient was started on tazobactam/piperacillin, she went into septic shock, and was transferred to our hospital. Cesarean section was performed at a gestation of 31 weeks and 4 days because of severe maternal pneumonia and non-reassuring fetal status. A. lwoffii was detected in blood cultures collected at the previous hospital, and susceptibility to piperacillin and meropenem to A. lwoffii was confirmed. The pneumonia responded to antibiotic treatment and there were no findings of infection in the neonate. Maternal sepsis is an infrequent but important complication, causing significant maternal and fetal morbidity and fetal and neonatal mortality; therefore, early antibiotic therapy is required to improve the clinical outcome. [ABSTRACT FROM AUTHOR]

Background & Aims: This study has the objective to examine the resistance of the clinical isolates of Acinetobacter lwoffii to antibiotics. Materials & Methods: The samples, that were isolated from the patients admitted to Gazi Hospital in Turkey, were defined by the MicroScan 5 WalkAway Identification System (Siemens, Germany) in terms of species and were thus collected. Then, the resistance pattern of 10 isolated A.lwoffii strains was assessed to 11 antibodies and four antibiotic compounds in this study. Results: 50% of the strains were found to be Multidrug-Resistant (MDR). Tigecycline was proved to be the most effective antibiotic with 80% sensitivity and 10% intermediate sensitivity. Conclusion: The MDR A.lwoffii strains were observed in the clinical isolate of Gazi hospital patients. Hence, the identification and investigation of the model of antibiotic resistance of the microorganisms is necessary.

Background: Non-Fermenting Gram-Negative Bacilli (NFGNB) are defined as strict aerobic and nonspore forming group of bacteria that do not ferment carbohydrates but generate energy required for their metabolic activities by oxidative pathway. NFGNB are known saprophytes, resilient in nature which allows them to survive even in the harshest hospital environment making them an apt etiological agent for nosocomial opportunistic infections. Urinary tract infections, ventilator-associated pneumonia, septicemia, and surgical site infection are some of the important hospital acquired infection associated with these agents. Aims & Objectives: 1. To isolate and speciate the non-fermenting Gram negative bacilli from various clinical specimens. 2. To find out the antimicrobial susceptibility pattern of isolated, non-fermenting Gram negative bacilli. Material and Methods: The present cross sectional study was conducted in the central laboratory of Sri Ramachandra medical college of higher education and research a tertiary care hospital. This study was undertaken after obtaining institutional ethical committee clearance. (REF: CSP/19/May/77/154) and lasted for a period of 3 months (October 2019 to December 2019). During our study period a total of 15838 clinical specimens were received in our laboratory for processing from OPD as well as hospitalized patients from various wards. The samples were processed according to standard procedures and were first subjected to direct Gram stain and then all specimens were inoculated onto routine culture medium (Blood agar, McConkey agar) except Urine specimens which was inoculated onto Cystine Lactose Electrolyte Deficient agar (CLED) and all plates were incubated at 37 oC. for 18-24 hours. Results and Observations: Out of 15838 clinical specimens that were collected in the time period of 3months (October 2019-December 2019), 5148 different types of organisms were isolated and in that 846 NFGNB. Which is 5% out of total number. Out of 846 isolates, 529 (62.52%) were isolated from Males and 317 (37.47%) were isolated from females. Conclusion: From this study we can conclude that NFGNB mainly causes wound infections followed by respiratory infections. Emergence of resistance to multiple anti-microbial agents is a problem and this study showed Acinetobacter baumannii as the most common multi drug resistant agent in comparison to others. MDR NFGNB was detected most commonly form urinary tract infection. Identification of NFGNB and monitoring their susceptibility patterns are important especially in those isolated from urine samples as highlighted by our study. [ABSTRACT FROM AUTHOR]

Bacterial pericarditis can be considered a rare pathology, usually associated with cardiac procedures and, to a lesser extent, with immunosuppression and chronic diseases. The importance of its knowledge lies in the fact that mortality can reach up to 100% in untreated patients. Once diagnosed, pericardiocentesis and administration of intravenous antimicrobial therapy are mandatory for the prevention of its complications, which include cardiac tamponade and sepsis. Here we present an exceptional case of infectious pericarditis due to Acinetobacter Lwoffii in an older adult, which was complicated by pericardial effusion and cardiac tamponade.

To identify causative bacteria of the death of wild mute swan(Cygnus olor),the suspected causative pathogen HeNSMX-1 was isolated from liver of dead wild mute swan in the Sanmenxia National Wetland Park of Swan Lake in August 2020.Using staining microscopy,MALDI-TOF identification,16S rDNA genetic evolutionary analysis,the strain was identified as Acinetobacter lwoffii.Then,Kirby-Bauer was used to evaluate antimicrobial susceptibility of the A.lwoffii strain HeNSMX-1.The results showed the strain was sensitive to amikacin,gatifloxacin,doxycycline,kanamycin,ciprofloxacin,cefotaxime,gentamicin and ofloxacin,and resistant to amoxycillin,ampicillin,cefixime. [ABSTRACT FROM AUTHOR]

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Acinetobacter species are gram negative non fermenters, which are important nosocomial pathogens involved in various outbreaks in hospitals due to widespread resistance to majority antibiotics. The aim of this study is to speciate Acinetobacter isolated from clinical samples, to assess the antibiotic sensitivity pattern and to detect the production of metallo-β-lactamase by double disc synergy test. The study was conducted in the department of microbiology, A.J Institute of Medical Sciences. All clinical samples were subjected to gram stain & cultured; the Acinetobacter isolates obtained were subjected to antibiogram. Those isolates that showed Imipenem resistant were further tested for production of metallo-β-lactamase by double disc synergy test. Out of 6625 culture positive isolates, 414 (36.1%) were identified biochemically to belong to Acinetobacter species. Of the 414 cases, 393 (94.9%) were further identified to be Acinetobacter baumannii and the remaining 21 (5.1%) to be Acinetobacter lwoffi. Acinetobacter lwoffii showed 100% sensitivity to all the drugs. Of the 393 Acinetobacter baumannii isolates 109(27.7%) showed resistant to Imipenem. Out of these 109 isolates, 65 (59.63%) were positive for metallo-β-lactamase production by double disk synergy test. The speciation is highly demanding and laborious but it’s important to be demonstrated due to difference in the antibiotic susceptibility pattern. Carbapenem resistant Acinetobacter nosocomial strains in ICUs are detected to be more resistant to antibiotics. As shown in this study the metallo-β-lactamase producing A.baumannii isolates were 59.63% and therapeutic options were limited. Therefore early identification of metallo-β-lactamase producers is of great importance to start appropriate treatment and to control the spread.

Background: Exist of folate pathway inhibitor genes among Acinetobacter spp. isolates are regarded as a significant mechanism of resistance for sulfa drugs in this pathogen. Objective: This study aimed to investigate genes associated with sulfa drugs resistance among Acinetobacter spp. using Polymerase Chain Reaction (PCR). Patients and Methods: This study included 928 specimens from patients who visited the main hospitals and private clinic laboratories of AlNajaf City-Iraq. All specimens were cultivated and bacterial diagnosis was done according to standard methods. Antibiotics susceptibility and molecular investigation for sul-1, sul-2, sul-3, dfr-A, dfr-B, dfr-G and dfr-K for all Acinetobacter spp. isolates were done. Results: The rate of Acinetobacter spp. isolates were 28 (5.4%). Results showed a high resistance towards antibiotics classes, 28 (100%) of isolates were resistance to piperacillin, cefotaxime, ceftriaxone, ceftazidime and cefepime, while the lowest resistance rate was against minocycline reached 42.85. PCR showed 28 (100%) of Acinetobacter spp isolates were harbored sul-1 and drf-G genes. 25 (89.29%) and 21 (75%) of isolates were positive for sul-2 and drf-A genes respectively, while sul-3, drf-B and drf-K genes were not detected. Conclusion: There is a great deal of concern about antimicrobial agent resistance and also about the number of drugassociated resistance genes contained in Acinetobacterspp. isolates especially sul-1, sul-2, dfr-A, and dfr-G, which have a significant role in sulfa drug resistance. [ABSTRACT FROM AUTHOR]

Background: Although lung macrophages are directly exposed to external stimuli, their exact immunologic roles in asthma are still largely unknown. The aim of this study was to investigate the anti‐asthmatic effect of Acinetobacter lwoffii in terms of lung macrophage modulation. Methods: Six‐week‐old female BALB/c mice were sensitized and challenged with ovalbumin (OVA) with or without intranasal administration of A. lwoffii during the sensitization period. Airway hyperresponsiveness and inflammation were evaluated. Using flow cytometry, macrophages were subclassified according to their activation status. In the in vitro study, a murine alveolar macrophage cell line (MH‐S) treated with or without A. lwoffii before IL‐13 stimulation were analysed by quantitative RT‐PCR. Results: In a murine asthma model, the number of inflammatory cells, including macrophages and eosinophils, decreased in mice treated with A. lwoffii (A. lwoffii/OVA group) compared with untreated mice (OVA group). The enhanced expression of MHCII in macrophages in the OVA group was decreased by A. lwoffii treatment. M2 macrophage subtypes were significantly altered. A. lwoffii treatment decreased CD11b+M2a and CD11b+M2c macrophages, which showed strong positive correlations with Th2 cells, ILC2 and eosinophils. In contrast, CD11b+M2b macrophages were significantly increased by A. lwoffii treatment and showed strong positive correlations with ILC1 and ILC3. In vitro, A. lwoffii down‐regulated the expression of M2 markers related but up‐regulated those related to M2b macrophages. Conclusions and Clinical Relevance: Intranasal A. lwoffii exposure suppresses asthma development by suppressing the type 2 response via modulating lung macrophage activation, shifting M2a and M2c macrophages to M2b macrophages. [ABSTRACT FROM AUTHOR]

[Display omitted] • C and P sources regulated the growth and the P metabolism of P5, respectively. • P removal and recovery activities of P5 were activated (P/C ≥1/40). • P removal and recovery activities of P5 were inhibited (P/C ≤1/100). • P removal and recovery performance of P5 had little relationship with the growth. • P recovery rate of P5 was the highest (82.07 %) with sufficient C and P sources. The growth and metabolism of polyphosphate accumulating organisms (PAOs) affect the phosphorus (P) removal performance of the biofilm sequencing batch reactor (BSBR). A novel strain PAO Acinetobacter lwoffii (P5) was isolated and identified from the BSBR. The growth conditions of P5 in BSBR were simulated with alternate aerobic (9 h)/anaerobic (6 h) cycles for 10 days. The orthogonal experiment showed that P and carbon (C) sources had significant interactions with the growth and P metabolism of P5 (P >0.05). The growth of P5 was mainly affected by the C source, but its P metabolism was mainly affected by the P source. Metabolism model, enzyme activity, and P recovery efficiency tests showed that when the sludge loading was 0.15 g P/(gMLSS·d), the P recovery efficiency was the highest (82.07 %). When the P/C ratio was ≥1/40, the P removal activity was activated, and the P removal performance of P5 was improved by the polyphosphate-accumulating metabolism (PAM). When the P/C ratio was ≤1/100, the P removal activity was inhibited, and the P removal performance of P5 was decreased by the glycogen-accumulating metabolism (GAM). Our research on the P mechanism of P5 provided valuable in-depth insights into the P removal performance of PAOs. [ABSTRACT FROM AUTHOR]

Phenol is a common environmental contaminant. The purpose of this study was to isolate phenol-degrading microorganisms from wastewater in the sections of the Chinese Medicine Manufactory. The phenol-degrading Acinetobacter lwoffii NL1 was identified based on a combination of biochemical characteristics and 16S rRNA genes. To analyze the molecular mechanism, the whole genome of A. lwoffii NL1 was sequenced, yielding 3499 genes on one circular chromosome and three plasmids. Enzyme activity analysis showed that A. lwoffii NL1 degraded phenol via the ortho-cleavage rather than the meta-cleavage pathway. Key genes encoding phenol hydroxylase and catechol 1,2-dioxygenase were located on a megaplasmid (pNL1) and were found to be separated by mobile genetic elements; their function was validated by heterologous expression in Escherichia coli and quantitative real-time PCR. A. lwoffii NL1 could degrade 0.5 g/L phenol within 12 h and tolerate a maximum of 1.1 g/L phenol, and showed resistance against multiple antibiotics and heavy metal ions. Overall, this study shows that A. lwoffii NL1 can be potentially used for efficient phenol degradation in heavy metal wastewater treatment.

A novel plasmid-encoded aminoglycoside 3''-nucleotidyltransferase ANT(3")-IId, was discovered in Acinetobacter lwoffi strain H7 isolated from a chick on an animal farm in Wenzhou, China. The whole-genome of A. lwoffii H7 consisted of one chromosome and five plasmids (pH7-250, pH7-108, pH7-68, pH7-48, and pH7-11). ant(3")-IId was identified as being encoded on pH7-250, sharing the highest amino acid identity of 50.64% with a function-known resistance gene, ant(3")-IIb (KB849358.1). Susceptibility testing and enzyme kinetic parameter analysis were conducted to determine the function of the aminoglycoside 3"-nucleotidyltransferase. The ant(3")-IId gene conferred resistance to spectinomycin and streptomycin [the minimum inhibitory concentration (MIC) levels of both increased 16-fold compared with the control strain]. Consistent with the MIC data, kinetic analysis revealed a narrow substrate profile including spectinomycin and streptomycin, with Kcat/Km ratios of 4.99 and 4.45×103M−1 S−1, respectively. Sequencing analysis revealed that the ant(3")-IId gene was associated with insertion sequences (IS) element [ΔISAba14-ΔISAba14-hp-orf-orf-orf1-ant(3")-IId], and ant(3")-IId were identified in plasmids from various Acinetobacter species. This study of the novel aminoglycoside 3"-nucleotidyltranferase ANT(3")-IId helps us further understand the functional and sequence characteristics of aminoglycoside 3"-nucleotidyltranferases, highlights the risk of resistance gene transfer among Acinetobacter species and suggests that attention should be given to the emergence of new aminoglycoside 3"-nucleotidyltranferase genes.

Phenol is a common environmental contaminant. The purpose of this study was to isolate phenol-degrading microorganisms from wastewater in the sections of the Chinese Medicine Manufactory. The phenol-degrading Acinetobacter lwoffii NL1 was identified based on a combination of biochemical characteristics and 16S rRNA genes. To analyze the molecular mechanism, the whole genome of A. lwoffii NL1 was sequenced, yielding 3499 genes on one circular chromosome and three plasmids. Enzyme activity analysis showed that A. lwoffii NL1 degraded phenol via the ortho -cleavage rather than the meta -cleavage pathway. Key genes encoding phenol hydroxylase and catechol 1,2-dioxygenase were located on a megaplasmid (pNL1) and were found to be separated by mobile genetic elements; their function was validated by heterologous expression in Escherichia coli and quantitative real-time PCR. A. lwoffii NL1 could degrade 0.5 g/L phenol within 12 h and tolerate a maximum of 1.1 g/L phenol, and showed resistance against multiple antibiotics and heavy metal ions. Overall, this study shows that A. lwoffii NL1 can be potentially used for efficient phenol degradation in heavy metal wastewater treatment. [ABSTRACT FROM AUTHOR]

A novel plasmid-encoded aminoglycoside 3''-nucleotidyltransferase ANT(3")-IId, was discovered in Acinetobacter lwoffi strain H7 isolated from a chick on an animal farm in Wenzhou, China. The whole-genome of A. lwoffii H7 consisted of one chromosome and five plasmids (pH7-250, pH7-108, pH7-68, pH7-48, and pH7-11). ant(3")-IId was identified as being encoded on pH7-250, sharing the highest amino acid identity of 50.64% with a function-known resistance gene, ant(3")-IIb (KB849358.1). Susceptibility testing and enzyme kinetic parameter analysis were conducted to determine the function of the aminoglycoside 3"-nucleotidyltransferase. The ant(3")-IId gene conferred resistance to spectinomycin and streptomycin [the minimum inhibitory concentration (MIC) levels of both increased 16-fold compared with the control strain]. Consistent with the MIC data, kinetic analysis revealed a narrow substrate profile including spectinomycin and streptomycin, with K cat/ K m ratios of 4.99 and 4.45×103M−1 S−1, respectively. Sequencing analysis revealed that the ant(3")-IId gene was associated with insertion sequences (IS) element [ΔIS Aba14 -ΔIS Aba14 -hp-orf-orf-orf1- ant(3")-IId ], and ant(3")-IId were identified in plasmids from various Acinetobacter species. This study of the novel aminoglycoside 3"-nucleotidyltranferase ANT(3")-IId helps us further understand the functional and sequence characteristics of aminoglycoside 3"-nucleotidyltranferases, highlights the risk of resistance gene transfer among Acinetobacter species and suggests that attention should be given to the emergence of new aminoglycoside 3"-nucleotidyltranferase genes. [ABSTRACT FROM AUTHOR]

Acinetobacter species are gram negative non fermenters, which are important nosocomial pathogens involved in various outbreaks in hospitals due to widespread resistance to majority antibiotics. The aim of this study is to speciate Acinetobacter isolated from clinical samples, to assess the antibiotic sensitivity pattern and to detect the production of metallo-ß-lactamase by double disc synergy test. The study was conducted in the department of microbiology, A.J. Institute of Medical Sciences. All clinical samples were subjected to gram stain & cultured; the Acinetobacter isolates obtained were subjected to antibiogram. Those isolates that showed Imipenem resistant were further tested for production of metallo-ß-lactamase by double disc synergy test. Out of 6625 culture positive isolates, 414 (36.1%) were identified biochemically to belong to Acinetobacter species. Of the 414 cases, 393 (94.9%) were further identified to be Acinetobacter baumannii and the remaining 21 (5.1%) to be Acinetobacter lwoffi. Acinetobacter lwoffii showed 100% sensitivity to all the drugs. Of the 393 Acinetobacter baumannii isolates 109(27.7%) showed resistant to Imipenem. Out of these 109 isolates, 65 (59.63%) were positive for metallo-ß-lactamase production by double disk synergy test. The speciation is highly demanding and laborious but it's important to be demonstrated due to difference in the antibiotic susceptibility pattern. Carbapenem resistant Acinetobacter nosocomial strains in ICUs are detected to be more resistant to antibiotics. As shown in this study the metallo-ß-lactamase producing A. baumannii isolates were 59.63% and therapeutic options were limited. Therefore early identification of metallo-ß-lactamase producers is of great importance to start appropriate treatment and to control the spread. [ABSTRACT FROM AUTHOR]

Recently, aquaculture in Egypt has faced multiple records of mass mortality resulting in high economic losses. The mass mortality among tilapia fries is mostly attributed to bacterial pathogens either with or without other pathogens. This study is designed to investigate the etiological factors implicated in mortality of the Nile tilapia fries. Bacteriological examination of the Nile tilapia fries including isolation and identification using a range of techniques (API NE20, Vitec, PCR and 16SrRNA Sequencing) revealed an array of typical pathogens known to cause lethal infections in tilapia. The most frequently isolated strains were Aeromonads 33.3% (A. veronii, A. sobria, A. hydrophila), Staphylococcus epidermidis, 11.1 % Pseudomonas aeruginosa, 11.1% and Shigella sonnei 11.1%. Furthermore, three emerging freshwater aquaculture pathogens which have zoonotic significance, namely Providencia rettgeri (11.1%), Shewanella putrefaciens (11.1%) and Acinetobacter lwoffii (11.1%) were isolated from fish fries. Despite known pathogenicity, inoculation of fish fingerlings with the different bacterial isolates resulted in only mild mortality rates under non-stress conditions, emphasizing the role of additional environmental stressors in triggering mass mortality of juvenile fish. Conclusively, these pathogens have a significant negative impact on tilapia fries, particularly in combination with environmental stress. [ABSTRACT FROM AUTHOR]

The gut microbiota is reported to play an important role in carcinogenesis and the treatment of CRC. SW480 and SW620 colon cancer cells integrated with infrared fluorescent proteins were injected into the rectal submucosa of nude mice. In the subsequent 30 days, we observed tumor growth weekly using an in vivo imaging system. The bacterial solution was infused anally into the mice to perform bacterial transplant. Phosphate-buffered saline, Acinetobacter lwoffii, and Bifidobacterium longum solutions were infused individually. The 16S ribosomal DNA (rDNA) and polymerase chain reaction of murine feces were investigated to confirm the colonization of target bacteria. In the SW620 orthotopic xenograft rectal cancer model, 4 of 5 mice developed rectal cancer by 30 days after submucosal injection. In the SW480 orthotopic xenograft rectal cancer model, 2 of 6 mice developed rectal cancer by 30 days after submucosal injection. For the 16S rDNA analysis, the mice receiving the bacterial solution infusion demonstrated positive findings for A. lwoffii and B. longum. With the successful establishment of a mouse model of orthotopic rectal cancer and transplant of target bacteria, we can further explore the relationship between gut microbiota and CRC. The role of fecal microbiota transplant in the treatment and alleviation of adverse events of chemotherapy in CRC could be clarified in subsequent studies.

The gut microbiota is reported to play an important role in carcinogenesis and the treatment of CRC. SW480 and SW620 colon cancer cells integrated with infrared fluorescent proteins were injected into the rectal submucosa of nude mice. In the subsequent 30 days, we observed tumor growth weekly using an in vivo imaging system. The bacterial solution was infused anally into the mice to perform bacterial transplant. Phosphate-buffered saline, Acinetobacter lwoffii , and Bifidobacterium longum solutions were infused individually. The 16S ribosomal DNA (rDNA) and polymerase chain reaction of murine feces were investigated to confirm the colonization of target bacteria. In the SW620 orthotopic xenograft rectal cancer model, 4 of 5 mice developed rectal cancer by 30 days after submucosal injection. In the SW480 orthotopic xenograft rectal cancer model, 2 of 6 mice developed rectal cancer by 30 days after submucosal injection. For the 16S rDNA analysis, the mice receiving the bacterial solution infusion demonstrated positive findings for A. lwoffii and B. longum. With the successful establishment of a mouse model of orthotopic rectal cancer and transplant of target bacteria, we can further explore the relationship between gut microbiota and CRC. The role of fecal microbiota transplant in the treatment and alleviation of adverse events of chemotherapy in CRC could be clarified in subsequent studies. [ABSTRACT FROM AUTHOR]

Microbial life can be supported at subzero temperatures in permafrost up to several million years old. Genome analysis of strains isolated from permafrost provides a unique opportunity to study microorganisms that have not previously come into contact with the human population. Acinetobacter lwoffii is a typical soil bacterium that has been increasingly reported as hospital pathogens associated with bacteremia. In order to identify the specific genetic characteristics of ancient permafrost-conserved strains of A. lwoffii and their differences from present-day clinical isolates, we carried out a genome-wide analysis of five strains of A. lwoffii isolated from permafrost aged from 15 thousand to 1.8 million years. Surprisingly, we did not identify chromosomal genetic determinants that distinguish permafrost strains from clinical A. lwoffii isolates and strains from other natural habitats. Phylogenetic analysis based on whole genome sequences showed that permafrost strains do not form a separate cluster and some of them are most closely related to clinical isolates. The genomes of clinical and permafrost strains contain similar mobile elements and prophages, which indicates an intense horizontal transfer of genetic material. Comparison of plasmids of modern and permafrost strains showed that plasmids from the modern strains are enriched with antibiotic resistance genes, while the content of genes for resistance to heavy metals and arsenic is nearly the same. The thawing of permafrost caused by global warming could release new potentially pathogenic strains of Acinetobacter.

Background and Objectives: In recent years, reports of Acinetobacter strains resistant to all known antibiotics have caused a great concern in medical communities. Overexpression of efflux pumps is one of the major causes of resistance in bacteria. The aim of this study was to investigate the role of efflux pumps in conferring resistance to imipenem in clinically important Acinetobacter spp; Acinetobacter baumannii and Acinetobacter lwoffii. Materials and Methods: A total number of 46 clinical Acinetobacter isolates, including 33 A. baumannii and 13 A. lwoffii isolates, previously collected from Shahid Kamyab and Ghaem hospitals of Mashhad, Iran were used in this study. Imipenem susceptibility testing was carried out by the disc diffusion method. Imipenem minimum inhibitory concentration (MIC) for resistant Acinetobacter isolates were determined both in the presence and absence of the efflux pumps inhibitor, carbonyl cyanide 3-chlorophenylhydrazone (CCCP). Results: Resistance to imipenem was observed in 38 isolates including 30 A. baumannii and 8 A. lwoffii isolates. Experiments in the presence of CCCP showed a 2 to 16384 fold reduction in imipenem MICs in 14 A. baumannii and 2 A. lwoffii isolates. Conclusion: The results obtained showed high levels of resistance to imipenem and contribution of efflux pumps in conferring resistance in both Acinetobacter species in this study. Moreover, imipenem efflux mediated resistance highlights the importance of this mechanism not only in A. baumannii but also in non-baumannii Acinetobacter Spp. which have been neglected in antibiotic resistance studies.

Background and Objectives: In recent years, reports of Acinetobacter strains resistant to all known antibiotics have caused a great concern in medical communities. Overexpression of efflux pumps is one of the major causes of resistance in bacteria. The aim of this study was to investigate the role of efflux pumps in conferring resistance to imipenem in clinically important Acinetobacter spp; Acinetobacter baumannii and Acinetobacter lwoffii. Materials and Methods: A total number of 46 clinical Acinetobacter isolates, including 33 A. baumannii and 13 A. lwoffii isolates, previously collected from Shahid Kamyab and Ghaem hospitals of Mashhad, Iran were used in this study. Imipenem susceptibility testing was carried out by the disc diffusion method. Imipenem minimum inhibitory concentration (MIC) for resistant Acinetobacter isolates were determined both in the presence and absence of the efflux pumps inhibitor, carbonyl cyanide 3-chlorophenylhydrazone (CCCP). Results: Resistance to imipenem was observed in 38 isolates including 30 A. baumannii and 8 A. lwoffii isolates. Experiments in the presence of CCCP showed a 2 to 16384 fold reduction in imipenem MICs in 14 A. baumannii and 2 A. lwoffii isolates. Conclusion: The results obtained showed high levels of resistance to imipenem and contribution of efflux pumps in conferring resistance in both Acinetobacter species in this study. Moreover, imipenem efflux mediated resistance highlights the importance of this mechanism not only in A. baumannii but also in non-baumannii Acinetobacter Spp. which have been neglected in antibiotic resistance studies. [ABSTRACT FROM AUTHOR]

Biodegradation of short-chain-length polyhydroxyalkanoates (scl-PHAs) and medium-chain-length polyhydroxyalkanoates (mcl-PHAs) was studied using 2 bacteria, Pseudomonas chlororaphis and Acinetobacter lwoffii, which secrete an enzyme, or enzymes, with lipase activity. These bacteria produced clear zones of depolymerization on Petri plates containing colloidal solutions of PHA polymers with different monomer compositions. Lipase activity in these bacteria was measured using p-nitrophenyl octanoate as a substrate. In liquid medium, scl-PHA (e.g., PHBV) and mcl-PHA (e.g., PHO) films were used as the sole carbon source for growth, and after 7 days, 5%–18% loss in mass of PHA films was observed. Scanning electron microscopy of these films revealed bacterial colonization of the polymers, with cracks and pitting in the film surfaces. Degradation of polymers released 3-hydroxyhexanoate, 3-hydroxyoctanoate, and 3-hydroxydecanoate monomers into the liquid medium, depending on the starting polymer. Genes encoding secretory lipases, with amino acid consensus sequences for lipase boxes and oxyanion holes, were identified in the genomes of P. chlororaphis and A. lwoffii. Although amino acid consensus sequences for lipase boxes and oxyanion holes are also present in PHA depolymerases identified in the genomes of other PHA-degrading bacteria, the P. chlororaphis and A. lwoffii lipases had low homology with these depolymerases. [ABSTRACT FROM AUTHOR]

Abstract In 1986, Bouvet and Grimont delineated two related taxa of the genus Acinetobacter termed genospecies (GS) 8 and 9. They proposed the name Acinetobacter lwoffii for GS8, which included the supposed type strain (CIP 64.10). As the authenticity of CIP 64.10 was later questioned, this study aimed at reassessing the taxonomy of these genospecies. We investigated 52 strains of GS8 or GS9, including CIP 64.10 and the genuine type strain of A. lwoffii (NCTC 5866T). All strains were subjected to the genus-wide comparative analyses of MALDI-TOF whole-cell mass spectra, rpoB gene sequences and metabolic traits while whole-genome sequences were analysed for 16 strains. The strains were classified into two distinct groups corresponding to GS8 (n = 15) and GS9 (n = 37). CIP 64.10 fell within GS8 whereas NCTC 5866T belonged to GS9. Intraspecies ANIb values for the genomes of GS8 (n = 6) and GS9 (n = 10) were ≥96.1% and ≥95.4%, respectively, whereas the ANIb values between them were 86.8–88.6%. Based on core genome phylogeny, GS8 and GS9 formed a distinct clade within the genus, with two respective, strongly supported subclades. GS8 and GS9 were similar in physiological and catabolic properties but were separable by MALDI-TOF MS. We conclude that the name A. lwoffii pertains to GS9 and not to GS8 as originally assumed and that these groups represent two species. We propose the name Acinetobacter pseudolwoffii sp. nov. for GS8, with ANC 5044T (= CCM 8638T = CCUG 67963T = CIP 111642T) as the type strain, and provide the emended description of A. lwoffii. [ABSTRACT FROM AUTHOR]

Abstract Acinetobacter baumanni is recognized as one of the most important agents of nosocomial infections. Other species such as Acinetobacter lwoffii have also been associated with such infections. These species can be found in food products, such as vegetables, fruits and meats which can be a source of transmission of these organisms to community and hospital settings. Evidence that hospitals' kitchens are a route of entry of pathogenic and antimicrobial-resistant bacteria was recently demonstrated. This study aimed to determine whether different Acinetobacter spp. isolated from human and food samples (lettuce, turkey meat, apple and pear) were resistant to stress conditions often applied in food processes, such as exposure to 60 °C, AMUKINA® and vinegar. Also the influence of food matrices on the behavior of isolates to these stress conditions was evaluated. Treatment with AMUKINA® and vinegar were effective against all clinical and food isolates. Exposure to 60 °C resulted in the reduction of the majority of isolates to values below the detection limit of the enumeration technique, however, it is important to note that most of the reductions only occurred after 30 min of exposure. One food isolate identified as A. baumanni was resistant to this thermal treatment and one clinical isolate only decreased 4 log cycles after 1 h. In general, food isolates were demonstrated to be more resistant than clinical isolates and no significant differences (p > 0.05) were found between A. baumanni and A. lwoffii species. With the exception of one food isolate that was more resistant to thermal stress in the presence of turkey meat, the food matrices investigated did not confer protection to the applied stresses. Due to the limited knowledge on this topic, we believe that this study is an important contribution to understanding the behavior of Acinetobacter spp. when exposed to treatments commonly applied to foods. Highlights • Acinetobacter isolated from human and food (lettuce, turkey meat, apple and pear) were used. • Treatment with AMUKINA® and vinegar were effective against all clinical and food isolates. • Exposure to 60 °C was not effective, but allowed the reduction of the majority of isolates. • Food matrices investigated did not confer protection to the applied stresses. • Food isolates demonstrated to be more resistant than clinical isolates. [ABSTRACT FROM AUTHOR]

The functioning of well-studied key groups of soil microorganisms depends on the microbial ecosystem in which they function in interaction with species belonging to other ecological groups. An analysis of the composition of the soil microbiota, and the possibility of analyzing the number of representatives of specific species, remains an urgent task of soil microbiology. Such analysis could be performed using modern and expensive methods such as metagenomics and mass-spectrometry, but some questions could also be answered using real-time PCR. This well-known approach is rather cheap for massive analysis and is ready to present reproducible results for practical agricultural applications. Understanding the variability of the primary structure of 16S rRNA is key to the reliable identification of bacterial species and provides an opportunity to choose the optimal pathways for their detection by PCR. In this work, analysis of the sequences of 16S rRNA of two species of soil bacteria, Acinetobacter lwoffii and Paenibacillus taichungensis is carried out. The most variable and most conservative areas on the level of species are detected. It was proved that conventional variable and conservative areas of the gene have on average nearly the same level of variability on the intraspecies level.

The incidence of Acinetobacter infections has increased in recent years. Acinetobacter infections are resistant to most antibiotics and can be found in hospitalized patients. Pregnancies complicated by severe sepsis or septic shock are associated with a higher rate of preterm labor and delivery, fetal infection, and operative delivery. This case report describes septic shock due to Acinetobacter lwoffii infection in the 31st week of gestation. A 47-year-old woman, with a gestation of 31 weeks and one day, presented with a fever, and signs of bacterial infection on laboratory tests. Although the patient was started on tazobactam/piperacillin, she went into septic shock, and was transferred to our hospital. Cesarean section was performed at a gestation of 31 weeks and 4 days because of severe maternal pneumonia and non-reassuring fetal status. A. lwoffii was detected in blood cultures collected at the previous hospital, and susceptibility to piperacillin and meropenem to A. lwoffii was confirmed. The pneumonia responded to antibiotic treatment and there were no findings of infection in the neonate. Maternal sepsis is an infrequent but important complication, causing significant maternal and fetal morbidity and fetal and neonatal mortality; therefore, early antibiotic therapy is required to improve the clinical outcome.

Acinetobacter lwoffii, a serious human pathogen, has been identified as a cause of nosocomial infections such as bacteremia, pneumonia and meningitis. There are only a few studies reporting A. lwoffii as a pathogen of fish. During 2016 and 2017, six bacterial strains, isolated from diseased fish of the Schizothorax genus, were identified as A. lwoffii by morphology, biochemical tests, 16S rDNA and gyrB gene sequencing analysis. One of these isolates was selected for experimental infection of Sclizothorax prenanti, Schizothorax davidi and Schizothorax wangchiachii, to confirm its pathogenicity. Experimentally infected fish showed similar symptoms to those observed in fish after natural outbreaks. Susceptibility of the isolates to 14 antibiotics was tested using a disc diffusion method; all isolates were resistant to cephalothin, aminoglycosides and β‐lactams, and sensitive only to some fluoroquinolones and tetracyclines. Histological examination revealed that A. lwoffii infection could cause pathological lesions in multiple organs and tissues, especially in liver, kidney, spleen and heart. These lesions included extensive haemorrhage, vacuolar degeneration, necrosis and inflammatory cell infiltration. To our knowledge, this is the first report on A. lwoffii as a virulent pathogen for fish of the Schizothorax genus. [ABSTRACT FROM AUTHOR]

Objectives: Numerous studies investigated multi-drug resistance and biofilm formation, but not determined the concentration of antibiotics which can be as anti-biofilm. Acinetobacter lwoffii is opportunistic pathogen that is caused increasing rate of hospital-acquired infections. Methods: A. lwoffii isolates from urinary tract infection are MDR. Results: A. lwoffii was resistance to all antibiotics that were tested. The planktonic cells of A. lwoffii 1 and A. lwoffii 7 show resistance (256 and 32) μg/ ml toward meropenem and levofloxacin respectively, as well as strong resistance (ND) for ceftazidime, amikacin and gentamicin. The biofilm cells MICs results were significantly P < 0.005 higher than the planktonic MICs. Pattern of biofilm ability for #1 and #7 with 2 μg/ ml meropenem and without showed great tendency to shape a biofilm, where A. lwoffii 1 (1.1) followed by A. lwoffii 7 (1.07). Conclusion: An interesting observation was the formation of biofilm showed enormous decline at a concentration 32 μg /ml with the presence of meropenem. The intracellular secondary messenger c-di-GMP also significantly declined with meropenem 32 μg /ml, hence, this confirm the estimation that meropenem affect biofilm formation. [ABSTRACT FROM AUTHOR]

Arsenic, a carcinogenic and toxic contaminant of soil and water, affects human health adversely. During last few decades, it has been an important global environmental issue. Among several arsenic detoxification methods remediation using arsenic resistant microbes is proved to be environment-friendly and cost-effective. This study aimed to test the effects of arsenic utilizing bacterial strain Acinetobacter lwoffii (RJB-2) on arsenic uptake and growth of mung bean plants ( Vigna radiata ). RJB-2 exhibited tolerance up to 125 mM of arsenic (V) and 50 mM of arsenic (III). RJB-2 produced plant growth promoting substances e.g. indole acetic acid (IAA), siderophores, exopolysaccharide (EPS) and phosphate solubilization in the absence and in presence of arsenic. Pot experiments were used to scrutinize the role of RJB-2 on arsenic uptake and growth of mung bean plants grown in soil amended with 22.5 mg kg − 1 of sodium arsenate (Na 2 HAsO 4 ·7H 2 O). RJB-2 could arrest arsenic uptake in just 7 days and increase plant growth, number of plants per pot, chlorophyll and carotenoid content of the mung bean plants. RJB-2 formed biofilm and its root-association helped to abate arsenic uptake in mung bean. Confocal and light microscopic studies also revealed the abatement of arsenic uptake and increase in chlorophyll content in mung bean plants in presence of RJB-2. RJB-2 was also responsible for less production of reactive oxygen species (ROS) in mung bean plants reducing the oxidative damage caused by arsenic. The lower percentage of electrolytic leakage (EL) in RJB-2 inoculated mung bean plants proved arsenic abatement. The study also reported the distribution of arsenic in various parts of mung bean plant. RJB-2 owing to its intrinsic abilities of plant growth promotion even in presence of high concentrations of arsenic could inhibit arsenic uptake completely and therefore it could be used in large-scale cultivation for phytostabilization of plants. [ABSTRACT FROM AUTHOR]

A novel mobile genetic element has been identified in small plasmids isolated from permafrost strains of Acinetobacter Iwoffii. This element, designated the chrAB dif module, contains the chromium resistance genes chrA and chrB, functionally active both in the original host strains and after transfer into Acinetobacter baylyi. The 3011 bp chrAB dif module is flanked by XerC/XerD recombination sites highly homologous to those of the site-specific recombination system dif/Xer. Analysis of public databases revealed almost identical variants of the chrAB difmodule in different plasmids in strains of various Acinetobacter species predominantly inhabiting the environment (A. lwoffii, Acinetobacter indicus, Acinetobacter idrijaensis, Acinetobacter shindleri and Acinetobacter nosocomialis). Together with previously described Acinetobacter antibiotic resistance elements, the chrAB difmodule defines a new group of mobile elements that rely on the dif/Xer system for their mobility. Our observations suggest an ancient origin of the mobile elements flanked by dif sites and their participation in the mobilization of plasmid genes bearing adaptive functions. [ABSTRACT FROM AUTHOR]

Members of the genus Acinetobacter are important opportunistic pathogens responsible for various nosocomial infections. However, Acinetobacter spp. are rarely isolated from fish. In this study, we isolated a dominant bacterial strain named I-702 from diseased hybrid sturgeons (Acipenser baerii ♀ × Acipenser schrenckii ♂) bred at a farm in Yichang City, Hubei Province, China. We identified the strain as Acinetobacter lwoffii based on morphological, physiological and biochemical, and 16S rRNA gene sequence analyses. Regression infection experiments using strain I-702 showed that the symptoms of the artificially infected fish were the same as those of natural diseased sturgeons, such as abdominal congestion and redness and swelling of cloaca. We calculated that the median lethal dose (LD 50) of strain I-702 for hybrid sturgeons was 1.22 × 102 ± 0.11 colony forming units/g fish. We also compared the proportion of different leukocytes between healthy and diseased fish; the proportion of neutrophils (30.89%) and monocytes (36.68%) in infected fish increased significantly, whereas that of lymphocytes (30.17%) decreased. Histopathological examination revealed that strain I-702 caused damage to the liver, and intestine tissues of sturgeons. Gut microbial analysis revealed that I-702 infection caused dysbiosis in sturgeons. The relative abundance of Acinetobacter in the diseased group (54.4%) was significantly higher than that in the healthy group (10.7%), whereas the relative abundance of Cetobacterium decreased significantly (healthy sturgeon: 25.6%, diseased sturgeon: 1.5%). Strain I-702 was susceptible to aminoglycosides (neomycin sulfate, amikacin, and gentamycin) and tetracyclines (minocycline and doxycycline). These results suggest that A. lwoffii is an important pathogen of sturgeons. Moreover, the study provides a scientific basis for the control and prevention of A. lwoffii infection in fish. • This is the first report that Acinetobacter (I-702) was isolated from hybrid sturgeon. • Strain I-702 can cause pathological damage to multiple organs of sturgeon. • Strain I-702 infection breaks the original dynamic balance of gut microbiota. • I-702 infection can be treated with neomycin sulfate, minocycline, doxycycline. [ABSTRACT FROM AUTHOR]

Background: Aerobic non-fermenting Gram-negative bacilli (NFGNB) once considered as contaminants now associated with life-threatening infections and emerging as multi drug resistant nosocomial pathogens. Aim: Isolation and identification of NFGNB in all the clinical samples and to determine antibiotic susceptibility pattern of the isolated NFGNB. Materials and Methods: This study has been conducted in the Department of Microbiology at a tertiary care teaching hospital over a period of 2 months from September to October 2013. NFGNB were isolated and identified from clinical specimens by standard procedure and antibiotic sensitivity test was performed. Results: NFGNB isolation rate in the present study was 3.58%. Male to female ratio was 2.125. Pus was the most common specimen (21%) followed by tracheal aspirate (17%). Pseudomonas aeruginosa was the most common isolate (60%) followed by Acinetobacter baumannii (22%) and Acinetobacter lwoffii (12%). P. aeruginosa has shown good sensitivity to amikacin (83.3%), imipenem (80%) and piperacillin-tazobactam (73.3%) whereas A. baumannii showed multidrug resistance. Conclusion: It is necessary to identify NFGNB and to monitor their susceptibility pattern to guide the clinician for better care and management of patients. NFGNB are now emerging as organisms of nosocomial infections. Hence, antibiotic sensitivity testing and infection control measures are needed to prevent the emergence and spread of multi drug resistant NFGNB in health care settings.

South American Camelids have an increasing relevance in local economies, worldwide. These animals are bred for their meat, fur and as companion and therapy animals. Thus, their sanitary status should be well-established. According to the OIE (World Organization for Animal Health), respiratory infections mainly produced by Pasteurella spp. have been reported for camelids. It has been stated that this microorganism causes a mild disease, although many authors report it is an important cause of mortality among alpacas. Nevertheless, the incidence of infection by Pasteurella spp. in camelids still needs to be investigated. The aim of the present study was to analyze the occurrence of nasopharyngeal colonization of Lama glama by respiratory bacteria, and to assess the usefulness of serological tests for clinical diagnosis. The colonization was studied by culture techniques carried out with material taken by nasopharyngeal swabs. Bacterial isolates were first phenotypically characterized and then identified by MALDI/TOF-MS. The presence of specific serum antibodies was studied by ELISA and Western blot. In the present work Pasteurella spp. was not found. Nevertheless, we report for the first time, the colonization of L. glama by bacteria of the Acinetobacter lwoffii, at a reliable level in 19.4% of the animals. Acinetobacter species are found in different environmental sources, as well as vegetables, animals, and humans, and their role in infections has recently gained relevance. The results presented herein contribute to a better understanding of the respiratory microbiota in camelids, and increase the knowledge about environmental distribution of Acinetobacter non-baumanii species. Given that these respiratory bacteria might be the cause of infection among cattle, and even humans, this report highlights the need for further research. [ABSTRACT FROM AUTHOR]