Open Access

Skin and soft tissue infection suspiciously caused by Klebsiella pneumoniae in an aquaculture worker: A case report

  • Authors:
    • Caipeng Xie
    • Na Li
    • Yan Chen
    • Yongtao Liang
    • Libing Huang
    • Xiaoyang Xie
    • Dongming Wang
    • Haitao Wang
    • Guanjun Huang
  • View Affiliations

  • Published online on: April 23, 2024
  • Article Number: 34
  • Copyright : © Xie et al. This is an open access article distributed under the terms of Creative Commons Attribution License [CC BY 4.0].

Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )
Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )


Skin and soft tissue infections (SSTIs), which are mainly caused by Gram‑positive cocci existing on the skin surface, are more common than those caused by Gram‑negative bacteria; however, the role of Gram‑negative bacteria as emerging pathogens in SSTIs cannot to be ignored. Klebsiella pneumoniae is an opportunistic pathogenic bacterium that mainly inhabits the respiratory and intestinal tracts of humans and animals, as well as the environment, including aquaculture farms. This bacterium can cause multiple infections in humans and animals. The present study reports the case of a SSTI which was suspected to be caused by Klebsiella pneumoniae in a 74-year-old farmer with venous thrombosis. The patient had exposed his four bare limbs to the farmed shrimps and shrimp pond routinely. Pustule and skin ulcers were observed on both the legs of the patient. After receiving anti‑infection therapy, the SSTI was almost completely resolved on day 9 and the patient was then discharged.


Klebsiella pneumoniae (K. pneumoniae) is widely distributed in nature and also colonizes the human gut and respiratory tract. It is divided into the opportunistic, hypervirulent and multi-drug resistant groups (1). It has been reported that aquaculture farms and farmed species also contain organism K. pneumoniae (2,3). The opportunistic strains cause respiratory tract, urinary system or blood stream infections, while hypervirulent ones can result in liver abscesses and endophthalmitis (1). The strains have also been reported to cause skin and soft tissue infections (SSTIs), including diabetic foot ulcers (4), cellulitis (5) and necrotizing fasciitis (6).

The present study describes the case of a patient with SSTI, which was suspected to have been caused by K. pneumoniae infection. The patient was an aquaculture worker with venous thrombosis.

Case report

A 74-year-old male patient presented to the Department of Rheumatology and Immunology of the Central People's Hospital of Zhanjiang, Zhanjiang, China, with a complaint of redness and swelling in both lower extremities. Purulent discharge drained from the wounds scattered on the legs and some wounds were scabbing. Multiple forming scabs were observed in the upper extremities. There was no complaint of fever. He denied having a history of diabetes. The patient, an aquaculture worker, worked in the shrimp pond routinely. Of note, 6 months prior, after completing his work, he had noted pitting edema over his lower legs with an elevated skin temperature, but no obvious tenderness. The edema was relieved when he lay flat, but became aggravated following activities. Open weeping or crusted sores had developed in all four limbs simultaneously. However, the patient continued to work at the shrimp pond with bare legs and arms. He had sought medical advice in the outpatient department of the hospital 1 month prior. At that time, laboratory tests revealed a high-sensitivity C-reactive protein (hs-CRP) level of 10.65 mg/l, a white blood cell count of 12.3x109/l and a neutrophil count of 90.81%; the patient had then been treated with Cefuroxime (1 g, i.v. drip, bid) for almost 1 week.

Notably, the patient had felt pain and swelling in his left ankle 2 years prior, which was before the current presentation. Gradually, the swelling and pain involved his right ankle and both knees. The symptoms were repetitive and could be relieved by anodyne.

Upon admission to the authors' institution, the patient had a temperature of 36.7˚C, a respiratory rate of 20 breaths/min, a heart rate of 90 beats/min and a blood pressure of 101/72 mmHg. The electrocardiogram assessment was normal. On day 2, laboratory tests revealed a white blood cell count of 13.2x109/l, a neutrophil count of 92.4%, a lymphocyte count of 4.3%, a hs-CRP level of 200.08 mg/l and a markedly increased CD64 index of 23.91. Procalcitonin levels were within the normal range (0-0.5 ng/ml). Urine glucose was negative, while the random blood glucose level was 5.39 mmol/l. A color Doppler ultrasound (data not shown) revealed a small amount of effusion, synovial thickening and degenerative changes in the ankles, as well as arthritis in the knee joints. Immune system diseases were not considered, as no abnormalities in the examination results were found in antinuclear antibody, anti double stranded DNA antibody IgG, as well as the markers of vasculitis and rheumatoid arthritis. The diagnosis of SSTI was thus established.

Following the diagnosis of SSTI, the wounds of the patient were washed with normal saline and the secretion fluid from the ulceration (Fig. 1A) was sampled for pathogenic microbe culture upon admission. The patient was then commenced on treatment with Cefamandole Nafate (1 g i.v. drip, q8h) and a wet compress of ethacridine lactate solution was applied to the wounds on day 1 since admission. On day 3, the pus culture grew Pneumoniae subspecies (also named Friedlander bacillus), one sub-species of K. pneumoniae, which was identified using a fully automatic microbial identification system (VITEK 2 Compact system, bioMérieux France). The treatment was successful in relieving the redness and swelling. The wounds were found to have no fluid leakage. On day 4, the hs-CRP level was downregulated to 135.78 mg/l. The skin of the patient recovered (Fig. 1B-D). Pathogenic microbes in the skin sample could not be detected on day 6. However, the edema of the left leg worsened again. The patient had remained lying in bed in the past few days and the edema re-occurred as soon as he got up. A color Doppler ultrasound subsequently confirmed deep vein thrombosis and atherosclerosis in the left low extremities (Fig. 2), which explained the recurrent edema. The related indices of coagulation function, apart from fibrinogen (5.17 g/l) were in the normal range (2-4 g/l) and treatment was initiated with the anticoagulant, Rivaroxaban. The anti-infection therapy was maintained. With the redness and swelling exhibiting a marked reduction, the SSTI was almost completely resolved on day 9. The patient was then discharged.


SSTI, which is mainly caused by Gram-positive cocci, such as Staphylococcus aureus existing on the skin surface is more common than that of Gram-negative bacteria. The role of Gram-negative bacteria as emerging pathogens in SSTIs cannot to be ignored, with isolated microorganisms mainly comprising of Pseudomonas aeruginosa, K. pneumoniae, Escherichia coli and Enterobacter cloacae (7,8).

In the case presented herein, pustule and skin ulcers were observed on both the legs of the patient. Forming scars were also scattered over both upper extremities. The patient had exposed his four bare limbs to the shrimp pond for a long period of time. The impaired skin indicated a possible skin infection. A blood examination further confirmed the infection. The pathogen examination indicated was K. pneumoniae. The secondary infection of the ulcer surface on the limbs was considered. As has been reported, skin ulcers, disrupting the natural defense of the skin, as well as causing scar formation and poor blood perfusion, lead to a decrease in local immunity and thus render the ulcer surface an ideal site for bacterial proliferation and invasion (8). With development, skin ulcers become aggravated or even systemic infections can occur (8). Furthermore, chronic post-thrombotic syndrome on the left lower extremity was characterized by extremity pain, edema, venous claudication, skin changes and skin ulceration, and inflammatory responses impaired the skin barrier functions (9-12). As regards the patient in the present study, the swollen and fragile skin and soft tissue of the limbs, followed by frequent exposure to and stimulation by the shrimp pond water environment for a long period of time, may have led to further damage to the skin barrier.

On the one hand, K. pneumoniae is a conditional pathogen, originally colonizing in human mucous membranes, including the gastrointestinal tract and the oropharynx. However, when transported to distant sites or when it invades other tissue, it can cause infection. Skin ulcers increase the opportunistic infection of the bacterial colonization. As regards the patient described herein, perhaps K. pneumoniae invaded the distantly susceptible skin and induced the secondary infection. It is also possible for K. pneumoniae to spread to the patient's open wounds, causing secondary infection via other contact methods.

On the other hand, as the patient had continued the work even though he began to show symptoms, the susceptible skin became further damaged and the vulnerability to the infection by microorganisms in the aquaculture environments increased. Samples from water, sediment and farmed species from fish and shrimp farms include organisms that have been shown to be associated with human opportunistic infections, such as Escherichia coli, Pseudomonas putida and K. pneumoniae (13); however, the incidence and prevalence of the skin damage caused by K. pneumoniae and other bacteria within aquaculture environments as the source remain unknown. Of note, Escherichia coli, Pseudomonas putida and K. pneumoniae are widely present throughout the natural environment as conditional pathogenic bacteria. Escherichia coli and K. pneumoniae, belonging to the Enterobacteriaceae family, have been reported to be involved in diabetic foot ulcers, necrotizing fasciitis, burn wounds or other necrotizing soft tissue infections (14-18). As they sometimes may develop into extended spectrum β-lactamase-, carbapenem- and multiple drug-resistant strains, it is better to cultivate bacteria on the surface of ulcers, test drug sensitivity and select appropriate antibiotics (14-18). Pseudomonas putida, also a Gram-negative bacteria, is an uncommon cause of SSTIs. It is often associated with trauma or an immunocompromised state with malnutrition, immobility and peripheral vascular disease as risk factors (19-22). Gentamicin, amikacin, levofloxacin, ceftazidime, ciprofloxacin, carbapenems and other antibiotics can be used for the clinical treatment of Pseudomonas putida (19-22). When related infections caused by the aforementioned Gram-negative bacteria occur, the clinical characteristics include an increased white blood cell count, elevated CRP levels or sometime symptoms of fever. The aquaculture environment is the reservoir of certain bacteria, such as K. pneumoniae, which can be further transferred by the aquaculture supply chains (2,23,24). The prevalence of K. pneumoniae in aquaculture farms may be due to high stocking density, organic matter levels and poor quality of the aquatic environment in the intensive systems (25). K. pneumoniae may be associated with both fish and human infections, and has pathogenic significance for humans, in addition to SSTIs, also causing food-borne diseases, meningitis, urinary tract infections; thus, the potential risk in aquaculture and public health should not be underestimated (3,24). It has also been reported that multi-drug resistant K. pneumoniae is present in aquaculture environments, such as shrimp farms and imported shrimp (2,3,26,27). Therefore, based on the cultured strain K. pneumoniae in pus, the present study suggests that K. pneumoniae infection in the patient was perhaps related to the long-term exposure of the skin ulcers to the shrimp pond. It can be deduced that long-term exposure to an aquaculture environment in which K. pneumoniae is prevalent, is likely to increase the risk of K. pneumoniae infection; for example, Vibrio vulnificus infection can be caused by exposure to the marine environment (28). As regards the role of the aquaculture environment as a potential source of K. pneumoniae infection, aquaculture-associated bacteria transferred between animals and humans via aquaculture supply chains may require further attention. Larger numbers of samples and clinical cases need to be analyzed in order to prove that human opportunistic SSTI can be caused by aquaculture-associated K. pneumoniae.

In the case presented herein, infection by other pathogens was not detected. However, it could not be completely ruled out that the cultured K. pneumoniae was the contaminating bacteria. The possibility of a Gram-positive co-infection can also not be ruled out. Following the treatment of the patient with a wet compress of ethacridine lactate solution and Cefamandole nafate empirically for the SSTI, the patient finally exhibited a good response against the K. pneumoniae infection identified.

The response indicated the sensitivity of the strain isolated. As Cephalosporin is a time-dependent antibiotic, the exposure lasting time of pathogenic bacteria to the antibiotic in the body is closely related to the antibacterial effect. The longer the concentration of antibiotic is maintained over the minimum inhibitory concentration, the better the antibacterial effect will be. The poorer effect of Cefuroxime (1 g i.v.drip, bid) used in the outpatient department before may partly have been due to its usage (bid) or insufficient treatment course.

In conclusion, the present study reported a suspected case of K. pneumoniae induced-SSTI accompanied by venous thrombosis-induced edema in an aquaculture worker.


Not applicable.


Funding: No funding was received.

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Authors' contributions

CX, YC and NL were main contributors to the conception of the study. CX was involved in the literature search for related studies. CX, YC, NL and YL were involved in the diagnosis and treatment of the patient. CX and YL wrote the original draft of the manuscript. YL and LH obtained and processed the images. LH interpreted of the patient's data. XX, DW and HW were involved in the literature review, provided advice on patient treatment and also involved in the revision of the manuscript. GH was involved in the microbiological testing. CX and YC confirmed the authenticity of all the raw data. All authors have read and approved the final version of the manuscript.

Ethics approval and consent to participate

The patient provided written consent for the inclusion of his data in the present study.

Patient consent for publication

The patient provided written consent for the publication of his data and any related images.

Competing interests

The authors declare that they have no competing interests.



Martin RM and Bachman MA: Colonization, infection, and the accessory genome of Klebsiella pneumoniae. Front Cell Infect Microbiol. 8(4)2018.PubMed/NCBI View Article : Google Scholar


Sivaraman GK, Rajan V, Vijayan A, Elangovan R, Prendiville A and Bachmann TT: Antibiotic resistance profiles and molecular characteristics of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae isolated from shrimp aquaculture farms in Kerala, India. Front Microbiol. 12(622891)2021.PubMed/NCBI View Article : Google Scholar


Sivaraman GK, Sudha S, Muneeb KH, Shome B, Holmes M and Cole J: Molecular assessment of antimicrobial resistance and virulence in multi drug resistant ESBL-producing Escherichia coli and Klebsiella pneumoniae from food fishes, Assam, India. Microb Pathog. 149(104581)2020.PubMed/NCBI View Article : Google Scholar


Du F, Ma J, Gong H, Bista R, Zha P, Ren Y, Gao Y, Chen D, Ran X and Wang C: Microbial infection and antibiotic susceptibility of diabetic foot ulcer in China: Literature review. Front Endocrinol (Lausanne). 13(881659)2022.PubMed/NCBI View Article : Google Scholar


Hu T, Wang M, Chen W, Zhao J and Xiong J: The clinical characteristic and outcome of skin and soft tissue infection in immunosuppressive patients with nephrotic syndrome. Clin Exp Nephrol. 24:779–788. 2020.PubMed/NCBI View Article : Google Scholar


Murali S, Pillai AV and Ramachandran R: Efficacy of colistimethate sodium as local application in necrotising fasciitis. BMJ Case Rep. 12(e232354)2019.PubMed/NCBI View Article : Google Scholar


Ioannou P, Tsagkaraki E, Athanasaki A, Tsioutis C and Gikas A: Gram-negative bacteria as emerging pathogens affecting mortality in skin and soft tissue infections. Hippokratia. 22:23–28. 2018.PubMed/NCBI


Yang H, Wang WS, Tan Y, Zhang DJ, Wu JJ and Lei X: Investigation and analysis of the characteristics and drug sensitivity of bacteria in skin ulcer infections. Chin J Traumatol. 20:194–197. 2017.PubMed/NCBI View Article : Google Scholar


Silva JC, Constâncio V, Lima P, Nunes C, Silva E, Anacleto G and Fonseca M: Determinants of quality of life in patients with post-thrombotic syndrome. Ann Vasc Surg. 85:253–261. 2022.PubMed/NCBI View Article : Google Scholar


Murphy KD: Mechanical thrombectomy for DVT. Tech Vasc Interv Radiol. 7:79–85. 2004.PubMed/NCBI View Article : Google Scholar


Dias MKHM, Madusanka DMD, Han EJ, Kim HS, Jeon YJ, Jee Y, Kim KN, Lee K, Fernando IPS and Ahn G: Sargassum horneri (Turner) C. Agardh ethanol extract attenuates fine dust-induced inflammatory responses and impaired skin barrier functions in HaCaT keratinocytes. J Ethnopharmacol. 273(114003)2021.PubMed/NCBI View Article : Google Scholar


Gertner E and Lie JT: Systemic therapy with fibrinolytic agents and heparin for recalcitrant nonhealing cutaneous ulcer in the antiphospholipid syndrome. J Rheumatol. 21:2159–2161. 1994.PubMed/NCBI


Huys G, Bartie K, Cnockaert M, Oanh DT, Phuong NT, Somsiri T, Chinabut S, Yusoff FM, Shariff M, Giacomini M, et al: Biodiversity of chloramphenicol-resistant mesophilic heterotrophs from Southeast Asian aquaculture environments. Res Microbiol. 158:228–235. 2007.PubMed/NCBI View Article : Google Scholar


Abdallah Z, Staibano P and Zhang H: Fatal necrotizing fasciitis mediated by Escherichia coli after parotidectomy and neck dissection: A case report and review of the literature. Ear Nose Throat J. 3(1455613231214918)2023.PubMed/NCBI View Article : Google Scholar


Álvaro-Afonso FJ, García-Álvarez Y, Tardáguila-García A, García-Morales E, López-Moral M and Lázaro-Martínez JL: Bacterial diversity and antibiotic resistance in patients with diabetic foot osteomyelitis. Antibiotics (Basel). 12(212)2023.PubMed/NCBI View Article : Google Scholar


Yang Y, Chu WL and Feng G: Retrospective analysis of 2 997 inpatients with skin and soft tissue injuries. Zhonghua Shao Shang Za Zhi. 20:821–829. 2020.PubMed/NCBI View Article : Google Scholar : (In Chinese).


Gibson D, Chow O, Seth I, Siu AHY and Kwei J: Compartment syndrome as a novel complication of extended spectrum beta lactamase Escherichia coli necrotising soft tissue infection-A case report. Int J Surg Case Rep. 99(107574)2022.PubMed/NCBI View Article : Google Scholar


Cen H and Zhang L: Management of carbapenem-resistant Klebsiella pneumoniae infection in a patient with diabetic foot ulcer and necrotizing soft tissue infection, bacteremia and lung infection: A case report. Asian J Surg. 43:930–931. 2020.PubMed/NCBI View Article : Google Scholar


Carpenter RJ, Hartzell JD, Forsberg JA, Babel BS and Ganesan A: Pseudomonas putida war wound infection in a US Marine: A case report and review of the literature. J Infect. 56:234–240. 2008.PubMed/NCBI View Article : Google Scholar


Chen CH, Hsiu RH, Liu CE and Young TG: Pseudomonas putida bacteremia due to soft tissue infection contracted in a flooded area of central Taiwan: A case report. J Microbiol Immunol Infect. 38:293–295. 2005.PubMed/NCBI


Thomas BS, Okamoto K, Bankowski MJ and Seto TB: A lethal case of Pseudomonas putida Bacteremia due to soft tissue infection. Infect Dis Clin Pract (Baltim Md). 21:147–213. 2013.PubMed/NCBI View Article : Google Scholar


Xie ZY, Xiong Y, Sun J, Yang ZL, Yang HU and Yang H: Epidemiological characteristics and antimicrobial resistance of 9l strains of Pseudomonas putida. Chin J Infect Control. 16:1185–1188. 2017.


Shen Y, Lv Z, Yang L, Liu D, Ou Y, Xu C, Liu W, Yuan D, Hao Y, He J, et al: Integrated aquaculture contributes to the transfer of mcr-1 between animals and humans via the aquaculture supply chain. Environ Int. 130(104708)2019.PubMed/NCBI View Article : Google Scholar


Salgueiro V, Manageiro V, Bandarra NM, Reis L, Ferreira E and Caniça M: Bacterial diversity and antibiotic susceptibility of Sparus aurata from aquaculture. Microorganisms. 8(1343)2020.PubMed/NCBI View Article : Google Scholar


Das A, Behera BK, Acharya S, Paria P, Chakraborty HJ, Parida PK and Das BK: Genetic diversity and multiple antibiotic resistance index study of bacterial pathogen, Klebsiella pneumoniae strains isolated from diseased Indian major carps. Folia Microbiol (Praha). 64:875–887. 2019.PubMed/NCBI View Article : Google Scholar


Pham TTH, Rossi P, Dinh HDK, Pham NTA, Tran PA, Ho TTKM, Dinh QT and De Alencastro LF: Analysis of antibiotic multi-resistant bacteria and resistance genes in the effluent of an intensive shrimp farm (Long An, Vietnam). J Environ Manage. 214:149–156. 2018.PubMed/NCBI View Article : Google Scholar


Yang JT, Xiao DY, Zhang LJ, Chen HX, Zheng XR, Xu XL and Jiang HX: Antimicrobial resistome during the transition from an integrated to a monoculture aquaculture farm in Southern China. Sci Total Environ. 882(163511)2023.PubMed/NCBI View Article : Google Scholar


Kushawaha A, Mobarakai N, Cooper M, Rose K and Awasum M: Necrotising fasciitis with Vibrio vulnificus: A limb threatening dermatologic complication following exposure to marine life. BMJ Case Rep. 6(bcr11.2009.2478)2010.PubMed/NCBI View Article : Google Scholar

Related Articles

Journal Cover

July-August 2024
Volume 4 Issue 4

Print ISSN: 2754-3242
Online ISSN:2754-1304

Sign up for eToc alerts

Recommend to Library

Copy and paste a formatted citation
Spandidos Publications style
Xie C, Li N, Chen Y, Liang Y, Huang L, Xie X, Wang D, Wang H and Huang G: Skin and soft tissue infection suspiciously caused by <em>Klebsiella</em> <em>pneumoniae</em> in an aquaculture worker: A case report. Med Int 4: 34, 2024
Xie, C., Li, N., Chen, Y., Liang, Y., Huang, L., Xie, X. ... Huang, G. (2024). Skin and soft tissue infection suspiciously caused by <em>Klebsiella</em> <em>pneumoniae</em> in an aquaculture worker: A case report. Medicine International, 4, 34.
Xie, C., Li, N., Chen, Y., Liang, Y., Huang, L., Xie, X., Wang, D., Wang, H., Huang, G."Skin and soft tissue infection suspiciously caused by <em>Klebsiella</em> <em>pneumoniae</em> in an aquaculture worker: A case report". Medicine International 4.4 (2024): 34.
Xie, C., Li, N., Chen, Y., Liang, Y., Huang, L., Xie, X., Wang, D., Wang, H., Huang, G."Skin and soft tissue infection suspiciously caused by <em>Klebsiella</em> <em>pneumoniae</em> in an aquaculture worker: A case report". Medicine International 4, no. 4 (2024): 34.